For decades, scientists have been grappling with what is considered to be the most fundamental question about the cosmos: How fast is our universe expanding? 



The rate of expansion influences everything from how galaxies form to how they might one day drift apart.



Determining the expansion rate of the universe, a number called the "Hubble constant," shapes our entire understanding of the cosmos, its age, and its ultimate fate.



<h2 class="wp-block-heading" id="h-hubble-tension-expansion-conundrum">"Hubble tension" expansion conundrum</h2>



Unfortunately, though many brilliant minds have dedicated their lives to finding the answer to this riddle, all who have tried thus far have failed, running repeatedly into a brick wall that has come to be known as the "Hubble tension."



Adam Riess, a physicist at <a href="https://www.jhu.edu/" target="_blank" rel="noreferrer noopener">Johns Hopkins University</a> in Baltimore, has been at the forefront of this debate. "With measurement errors negated, what remains is the real and exciting possibility that we have misunderstood the universe," Riess admitted.



Riess, who won a Nobel Prize for discovering that the universe's expansion is accelerating due to dark energy, has been working tirelessly to resolve what's known as the Hubble Tension.



<h2 class="wp-block-heading" id="h-why-the-hubble-constant-matters">Why the Hubble constant matters</h2>



But before diving deeper, let's consider why the expansion rate -- called the Hubble constant -- is so crucial. 



Named after Edwin Hubble, who first observed that galaxies are moving away from us, this constant helps us map out the history and future of everything we see in the night sky. 



Determining it with precision has been a major goal of astronomers for decades.



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/11/hubble-constant_3-steps_illustration_nasa_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/11/hubble-constant_3-steps_illustration_nasa_1s.webp" alt="This illustration shows the three basic steps astronomers use to calculate how fast the universe expands over time, a value called the Hubble constant. All the steps involve building a strong &quot;cosmic distance ladder,&quot; by starting with measuring accurate distances to nearby galaxies and then moving to galaxies farther and farther away. Credit: NASA" class="wp-image-1951709"/></a><figcaption class="wp-element-caption">This illustration shows the three basic steps astronomers use to calculate how fast the universe expands over time, a value called the Hubble constant. All the steps involve building a strong "cosmic distance ladder," by starting with measuring accurate distances to nearby galaxies and then moving to galaxies farther and farther away. Credit: NASA</figcaption></figure>



When the <a href="https://hubblesite.org/home" target="_blank" rel="noreferrer noopener">Hubble Space Telescope</a> was launched in 1990, one of its main objectives was to pin down the universe's expansion rate. 



Before Hubble, estimates of the universe's age ranged wildly from 10 to 20 billion years -- a huge uncertainty. 



Thanks to Hubble's observations of <a href="https://www.earth.com/news/expansion-rate-of-the-universe-confirmed-by-jwst/" target="_blank" rel="noreferrer noopener">Cepheid variable stars</a> -- stars that pulsate at regular intervals and serve as cosmic mileposts -- we now have a more precise age of about 13.8 billion years.



<h2 class="wp-block-heading" id="h-webb-telescope-to-the-rescue">Webb telescope to the rescue?</h2>



Some scientists wondered if the discrepancies in measurements were due to errors in Hubble's data. Maybe, they thought, the way Hubble measured distances had some hidden flaws. 



Then came the James Webb Space Telescope (<a href="https://science.nasa.gov/mission/webb/" target="_blank" rel="noreferrer noopener">Webb</a>), launched to great fanfare as the successor to Hubble. Webb's infrared observations of Cepheids matched Hubble's optical data perfectly. 



"Combining Webb and Hubble gives us the best of both worlds. We find that the Hubble measurements remain reliable as we climb farther along the cosmic distance ladder," Riess explained.



<h2 class="wp-block-heading" id="h-hubble-vs-webb-vs-expansion">Hubble vs. Webb vs. expansion</h2>



Despite the new data, the tension between measurements remains. The Hubble and Webb telescopes confirm one universe expansion rate, based on observations of the local universe.



Meanwhile, observations from the early universe, like those from the Planck satellite's mapping of the cosmic microwave background radiation, suggest another. 



This leaves cosmologists scratching their heads. Is there something about the <a href="https://www.earth.com/news/universe-expansion-rate-dark-energy-measured-11-billion-years-ago/" target="_blank" rel="noreferrer noopener">fabric of space</a> we don't yet understand? Does resolving this discrepancy require new physics, or is there another explanation?



<h2 class="wp-block-heading" id="h-brenda-frye-tackles-hubble-and-expansion">Brenda Frye tackles Hubble and expansion</h2>



In October 2024, <a href="https://blogs.nasa.gov/webb/2024/10/01/webb-researchers-discover-lensed-supernova-confirm-hubble-tension/" target="_blank" rel="noreferrer noopener">as reported by NASA</a>, Brenda Frye from the <a href="https://www.arizona.edu/" target="_blank" rel="noreferrer noopener">University of Arizona</a> and an international team took a different approach. 



They used <a href="https://www.earth.com/news/webb-telescope-finds-a-second-lensed-supernova-in-a-distant-galaxy/" target="_blank" rel="noreferrer noopener">gravitationally lensed supernovae</a> to measure the Hubble constant -- a method independent of previous techniques. 



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/11/hubble-constant_galaxy-cluster-G165_supernova-H0pe_gravitational-lensing_jwst_UArizona_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/11/hubble-constant_galaxy-cluster-G165_supernova-H0pe_gravitational-lensing_jwst_UArizona_1s.webp" alt="NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) image of the galaxy cluster PLCK G165.7+67.0, also known as G165, on the left shows the magnifying effect a foreground cluster can have on the distant universe beyond. The foreground cluster is 3.6 billion light-years away from Earth. The zoomed region on the right shows supernova H0pe triply imaged (labeled with white dashed circles) due to gravitational lensing. Credit: NASA, ESA, CSA, STScI, B. Frye (University of Arizona)" class="wp-image-1951711"/></a><figcaption class="wp-element-caption">NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) image of the galaxy cluster PLCK G165.7+67.0, also known as G165, on the left shows the magnifying effect a foreground cluster can have on the distant universe beyond. The foreground cluster is 3.6 billion light-years away from Earth. The zoomed region on the right shows supernova H0pe triply imaged (labeled with white dashed circles) due to gravitational lensing. Credit: NASA, ESA, CSA, STScI, B. Frye (University of Arizona)</figcaption></figure>



While observing a densely populated cluster of galaxies, they noticed something unusual. "What are those three dots that weren’t there before? Could that be a supernova?" the team wondered. 



It turned out to be a <a href="https://www.earth.com/news/webb-travels-back-in-time-to-better-understand-supernovae-science/" target="_blank" rel="noreferrer noopener">Type Ia supernova</a>, an explosion of a <a href="https://www.earth.com/news/white-dwarf-stars-may-be-billions-of-years-older-than-estimated/" target="_blank" rel="noreferrer noopener">white dwarf star</a>, magnified and split into multiple images by the gravitational lensing effect of the intervening galaxy cluster.



<h2 class="wp-block-heading" id="h-what-is-gravitational-lensing">What is gravitational lensing?</h2>



<a href="https://www.earth.com/news/rare-carousel-lens-galaxy-alignment-reveals-dark-matter-secrets/" target="_blank" rel="noreferrer noopener">Gravitational lensing</a> is important to this experiment. The lens, consisting of a cluster of galaxies situated between the supernova and us, bends the supernova's light into multiple images. 



This effect not only magnifies the supernova but also allows scientists to measure the time delays between the images, providing another way to calculate the Hubble constant.



Their analyses confirmed that these dots corresponded to an exploding star with rare qualities. 



The team's work provided a Hubble constant value of 75.4 kilometers per second per megaparsec, plus 8.1 or minus 5.5. For context, one megaparsec is about 3.26 million light-years. 



"Our team’s results are impactful: The Hubble constant value matches other measurements in the local universe, and is somewhat in tension with values obtained when the universe was young," Frye concluded.



Another strikeout... add Brenda Frye to the long list of brilliant minds still probing the universe for an answer to Hubble tension.



<h2 class="wp-block-heading" id="h-this-is-getting-sad-now-what">This is getting sad, now what?</h2>



So, where does this leave us? 



The Hubble Tension isn't going away. It might be telling us that there's new physics waiting to be discovered. 



Perhaps our understanding of <a href="https://www.earth.com/news/dark-energy-could-explain-the-rapid-expansion-of-the-early-universe/" target="_blank" rel="noreferrer noopener">dark energy</a>, dark matter, or other fundamental forces needs to be revised. 



"We need to find out if we are missing something on how to connect the beginning of the universe and the present day," Riess pointed out. 



It's possible that new theories or modifications to existing ones could bridge the gap.



<h2 class="wp-block-heading" id="h-shaking-things-up-with-new-theories">Shaking things up with new theories</h2>



Could the solution lie in something entirely unexpected? Perhaps there's a <a href="https://www.earth.com/news/dark-matter-may-consist-of-particles-that-travel-faster-than-light/" target="_blank" rel="noreferrer noopener">new particle or force</a> that affects the expansion rate. Or maybe the nature of dark energy changes over time. 



Some theories even propose the existence of extra dimensions or modifications to gravity at large scales. It's also worth considering that the universe might not be uniform in all directions. 



If there are variations in the density of matter and energy across vast distances, this could affect expansion rates in ways we haven't fully accounted for. 



Maybe everyone is completely off base and <a href="https://www.earth.com/news/study-dark-matter-does-not-exist-and-the-universe-is-27-billion-years-old/" target="_blank" rel="noreferrer noopener">dark matter doesn't even exist</a>? Or maybe we're looking in the wrong place -- what if the answers can be found by looking for <a href="https://www.earth.com/news/scientists-are-now-searching-for-dark-matter-inside-old-earth-rocks-minerals-crystals/" target="_blank" rel="noreferrer noopener">dark matter in rocks on Earth</a>?



One thing's for sure: the cosmos isn't giving up its secrets easily. But that's part of the thrill of science. Every answer leads to new questions.



<h2 class="wp-block-heading" id="h-hubble-constant-hubble-tension-mysterious-universe">Hubble constant, Hubble tension, mysterious universe</h2>



In the end, the universe is reminding us that there's still so much we don't know. The quest to figure out how fast our universe is expanding has led to some fascinating discoveries and even more intriguing questions. 



Scientists like Adam Riess and Brenda Frye have used powerful tools like the Hubble and James Webb Space Telescopes to measure the Hubble constant with increasing precision. 



Their efforts confirm that the local universe is expanding at a certain rate, but this doesn't quite line up with measurements from the early universe.



This mismatch, known as the Hubble Tension, suggests there might be something we’re missing in our understanding of the cosmos. Maybe there are new physics to uncover, or perhaps our current models need some tweaking. 



What's clear is that the universe isn't giving up its secrets easily, and that keeps things exciting for astronomers and physicists alike.



As we look ahead, upcoming missions like NASA's <a href="https://roman.gsfc.nasa.gov/" target="_blank" rel="noreferrer noopener">Nancy Grace Roman Space Telescope</a> and ESA's <a href="https://www.esa.int/Science_Exploration/Space_Science/Euclid" target="_blank" rel="noreferrer noopener">Euclid mission</a> offer hope for new insights. Until then, we can marvel at the fact that we're part of an ever-expanding universe that's still full of surprises.



The full study was published in the <a href="https://iopscience.iop.org/article/10.3847/2041-8213/ad1ddd" target="_blank" rel="noreferrer noopener">Astrophysical Journal Letters</a>.



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Webb telescope confirms: What we think we know about the universe is very wrong

For decades, scientists have been grappling with what is considered to be the most fundamental question about the cosmos: How fast is our universe expanding? The rate of expansion influences everything from how galaxies form to how they might one day drift apart. Determining the expansion rate of the universe, a number called the "Hubble constant," shapes our entire understanding of the cosmos, its age, and its ultimate fate. "Hubble tension" expansion conundrum Unfortunately, though many brilliant minds have dedicated their lives to finding the answer to...

Turbulence serves a source of energy that birds can use to their advantage, according to a new study led by <a href="https://www.cornell.edu/">Cornell University</a>. Instead of hindering the ability to fly, the experts found that turbulence seems to serve as a speed booster for birds. 

While the flight of birds may appear easy and graceful to earthbound spectators, winged animals are actually navigating air flow that is structured, textured and constantly in flux, explained Professor Gregory Bewley, who led the team.

For the investigation, the researchers partnered with two groups, Conservation Science Global and Cellular Tracking Technologies. The scientists captured a female golden eagle in Alabama and equipped the bird with a solar GPS telemetry unit that weighed less than three ounces.

Over the next 17 days, the eagle migrated north along the Appalachian Mountains toward Canada. During this time, the GPS "backpack" transmitted more than 200 hours of data including location, altitude, and speed through cellular networks.

The team also obtained wind speed data from the National Centers for Environmental Prediction, and compared it to the eagle's flight measurements. This allowed the experts to identify the bird's various flying and non-flying behaviors.

The researchers identified a "highly irregular, fluctuating pattern" in the eagle's accelerations. This pattern resembled the typical trajectories of particles in turbulent airflows.

For time periods ranging from 0.5 to 10 seconds, or approximately 1 to 25 wingbeats, the eagle's accelerations were completely in sync with atmospheric turbulence.

Professor Bewley believes there are opportunities to harness the energy of turbulence, particularly for autonomous transport and small reconnaissance aircraft.

"If you could find a path in which every vortex is pushing you the right way, then obviously you get there a little faster with a little less energy," said Professor Bewley. "We're still working hard to understand turbulence by itself. I think it's fascinating that there might be some practical empirical knowledge embodied in wildlife that we don't appreciate yet."

The study is published in the journal <a href="https://www.pnas.org/">Proceedings of the National Academy of Sciences</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Turbulence gives birds a speed boost

Turbulence serves a source of energy that birds can use...

Biodiversity hotspots along streams and rivers in California are threatened by intensive <a href="https://www.earth.com/news/how-ducks-balance-water-pressure-while-diving/">water</a> management. Rare plant species living in streamside forests can benefit from water that humans are diverting for their own needs, but these benefits are only short term, according to a new study from the <a href="https://www.esf.edu/">SUNY College of Environmental Science and Forestry</a>.

The experts report that natural communities have become dependent on an artificial water supply, threatening their long-term survival.

As water is rerouted from rivers, an environment is created that promotes a "live fast, die young" strategy among the trees in streamside forests. These trees peak and decline within a few decades, according to the report. 

Furthermore, the extensive changes to streams and river channels are fixed in place, which means that there are no new floodplain areas where young trees can become established.

Plants and animals in California rely on the rainy winter and spring seasons to replenish their water supply. Trees in streamside forests, including willows, cottonwoods, and oaks, seek out groundwater to survive dry summers. 

The researchers analyzed five years of vegetation greenness data from Google Earth satellite imagery. They found that many streamside forest ecosystems are dependent upon "subsidies of water" provided by human regulation of rivers, agricultural canals, and discharges from wastewater treatment plants. 

Rohde said the discovery of this artificially stable environment was a "mind bender." In the most arid regions of the state, altered streamside communities remained greener for longer into the dry season. These ecosystems were less responsive to changes in groundwater levels.

California's Central Valley produces a third of the produce for the United States. This is also site where many of the most-altered stream ecosystems were identified. 

The researchers noted that 95 percent of the natural floodplain woodlands have been cleared across the region since the Gold Rush of the 1850s. The isolated streamside forests that remain provide important habitats for many endangered species.

"We call these forests the 'living dead' because the forest floor is devoid of saplings and younger trees that can replace the mature trees when they die," said study lead author Melissa Rohde.

"California is one of the most biodiverse regions in the world, containing more species than the rest of the United States and Canada combined."

"In the midst of the sixth mass extinction, the long-term sustainability of California's river ecosystems and the preservation of the rare and endemic species that live within them now rely on the deliberate, coordinated management of resource and government agencies." 

Insights from the study will be used to provide scientific guidance to California natural resource agencies for sustainably managing streamside ecosystems.

"We need to be more intentional in incorporating ecosystem water needs when we manage water - both for aquatic organisms and species on land," said Rohde. 

"These forest ecosystems are in a precarious state because we have disrupted the natural hydrologic processes that these plant species rely upon to support and sustain key life processes."

The study is published in the journal <a href="https://www.pnas.org/">Proceedings of the National Academy of Sciences</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

California's streamside forests are threatened by water management

Biodiversity hotspots along streams and rivers in California are threatened...

Fires are a normal and natural part of life in the Rocky Mountains and much of the interior western United States. Hot summer days are normal too. It’s common knowledge today that humans are causing a shift in <a href="https://www.earth.com/news/butterflies-and-moths-are-struggling-to-adapt-to-climate-change/">climate</a> to favor warmer, drier weather. 

For years, scientists have predicted that a shift in climate would also come along with an increase in forest fires. Now researchers working in the central Rocky Mountains of southern Wyoming and northern Colorado have evidence that this is already happening. 

Paleoecologists with both the University of Wyoming and the <a href="https://www.umt.edu/">University of Montana</a> collected ash deposited in lake bed sediments to look at the history of wildfires in the area. What they found was shocking. Following the extreme fire season of 2020, the researchers discovered that more high elevation forests are burning than at any point in the past 2,000 years. 

"As the 2020 fire season unfolded, we realized we already had a well-defined understanding of the fire history of many of the places burning, based on over 20 lake-sediment records our teams had collected over the past 15 years," said study lead author Professor Phillip Higuera. 

"When the smoke settled, we thought 'Wow, we may have witnessed something truly unprecedented here.' So we combined the existing records for the first time and compared them to recent fire activity. To our surprise, 2020 indeed pushed fire activity outside the range of variability these forests have experienced over at least the past two millennia."

The experts found that high elevation forests, which historically burned at a rate of once every 230 years, are now burning at a rate of every 120 years. The record shows that as climate has varied, Rocky Mountains fires have followed trends - the hotter and drier, the more fires. While none of this is surprising, it is still shocking to realize the harsh consequences of human-induced climate change have already emerged. 

“It's sobering to see that it's clearly happening, and early in the 21st century - not in 2050, not in 2075, but by 2020," said Professor Higuera.

Not only are there more fires accompanying climate change, but also unprecedented rates of fires in forests that are fire adapted. As one last word of hope, Professor Higuera pointed out that if we as humans can cause this problem, possibly we can fix it as well. 

"It's critical to remember that we have ample opportunities to limit or reverse climate warming while still working to adapt to the increasing fire activity expected in upcoming decades."

The study is published in the <a href="https://www.pnas.org/">Proceedings of the National Academy of Sciences</a>.

---

By <a href="http://zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Unprecedented fires threaten the Central Rocky Mountains

Fires are a normal and natural part of life in...

The analysis of two 99 million-year-old fossils of the genus Oculudentavis has yielded some surprising results. Now that researchers have painstakingly examined the second fossil, they can confirm that the first was actually a lizard, even though it was initially believed to be a <a href="https://www.earth.com/news/noise-pollution-is-changing-which-birds-visit-your-backyard/">bird</a>. 

The species represented by the second fossil was named Oculudentavis naga in honor of the Naga people of Myanmar and India. The specimen, which is preserved in amber, consists of a partial skeleton, a complete skull, and visible scales and soft tissue.

The first fossil of this genus, Oculudentavis khaungraae, was mistakenly labeled as a hummingbird-sized dinosaur. Its original description as the smallest known bird was retracted last year. 

A team of experts led by Arnau Bolet of Barcelona's Institut Català de Paleontologia Miquel Crusafont used CT scans to digitally analyze and compare each bone in the two species. They found physical characteristics which confirmed that the tiny animals were lizards. 

Oculudentavis is so strange, however, it was difficult to categorize without close examination of its features, explained Bolet. "The specimen puzzled all of us at first because if it was a lizard, it was a highly unusual one."

"From the moment we uploaded the first CT scan, everyone was brainstorming what it could be," said Professor Juan Diego Daza of Sam Houston State University. "In the end, a closer look and our analyses help us clarify its position."

The characteristics that distinguished Oculudentavis as a lizard were the presence of scales, teeth attached directly to its jawbone, lizard-like eye structures and shoulder bones; and a hockey stick-shaped skull bone that is universal among scaled reptiles.

The team discovered that the skulls of both specimens had deformed during preservation. The distortions highlighted birdlike features in one skull and lizard-like features in the other, said study co-author Edward Stanley of the <a href="https://www.floridamuseum.ufl.edu/">Florida Museum of Natural History</a>.

"Imagine taking a lizard and pinching its nose into a triangular shape," said Stanley. "It would look a lot more like a bird."

The two skulls did not closely resemble one another at first, but the researchers said their shared characteristics became clearer as they isolated each bone and compared them with each other. 

"We concluded that both specimens are similar enough to belong to the same genus, Oculudentavis, but a number of differences suggest that they represent separate species," Bolet said.

Professor Daza noted that the Cretaceous Period, 145.5 to 66 million years ago, gave rise to many lizard and snake groups on the planet today, but tracing fossils from this era to their closest living relatives can be difficult.

"We estimate that many lizards originated during this time, but they still hadn't evolved their modern appearance," said Professor Daza. "That's why they can trick us. They may have characteristics of this group or that one, but in reality, they don't match perfectly."

The study is published in the journal <a href="https://www.cell.com/current-biology/home">Current Biology</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Strange prehistoric lizard was mistaken for a bird

The analysis of two 99 million-year-old fossils of the genus...

Ozone pollution levels dropped rapidly in American and Asian cities during the coronavirus pandemic, according to a new report from <a href="https://www.jpl.nasa.gov/">NASA’s Jet Propulsion Laboratory</a>. 

The researchers found that emissions of nitrogen oxides (NOx), which create ozone pollution, decreased by up to 50 percent in some regions as global commerce slowed and the burning of fossil fuels was reduced. 

The experts report that by June 2020, global ozone pollution had dropped to a level that policymakers thought would take at least 15 years to reach through regulations and other conventional means.

When ozone is high in the stratosphere, it protects life on Earth from harmful solar radiation. Close to the ground, however, ozone is very dangerous to human health. In 2019 alone, ozone pollution caused an estimated 365,000 deaths due to lung damage. 

Plants are also affected by ozone pollution, which impacts their ability to photosynthesize. This ultimately reduces plant growth and crop yields. Furthermore, higher up in the troposphere, ozone acts as a heat-trapping greenhouse gas that increases global temperatures.

A team of international researchers led by JPL scientist Kazuyuki Miyazaki set out to investigate how human activity affects levels of nitrogen oxide and nitrogen dioxide, which are collectively called NOx. The experts found that the greatest reductions in NOx emissions were tied to the nations with the strictest COVID-19 lockdown measures.

In some Chinese cities, stay-at-home orders in early February 2020 resulted in a 50 percent drop in NOx emissions within a few weeks. Later in the spring,  most U.S. states achieved a 25 percent drop.

According to the study, ozone reductions from the reduced NOx emissions quickly spread both around the globe and from the surface upward more than 6 miles.

The results of the study suggest that strategies designed to decrease ozone pollution on a local level have the potential to rapidly improve air quality worldwide. 

“I was really surprised at how large the impact on global ozone was,” said study co-author and JPL scientist Jessica Neu. “We expected more of a local response at the surface.”

“I was very happy that our analysis system was able to capture the detailed changes in emissions across the world,” said Miyazaki. “The challenging and unprecedented nature of this work is a testament to improvements in satellite monitoring in service of societal needs.” 

The study is published in the journal <a href="https://advances.sciencemag.org/">Science Advances</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Ozone pollution dropped dramatically during pandemic

Ozone pollution levels dropped rapidly in American and Asian cities...

The northern lights are created by high-powered electromagnetic waves that propel electrons toward Earth at a speed of millions of miles per hour. This decades-old theory has been confirmed in a new study by scientists at the <a href="https://uiowa.edu/">University of Iowa</a>.

"The shimmering displays of the aurora borealis have always fascinated humankind since the dawn of civilization, first inspiring both awe and fear for their seemingly mysterious origin, but more recently capturing the attention of scientists curious to explain what causes this natural phenomenon," study co-author Professor Greg Howes writes in the journal <a href="https://www.nature.com/ncomms/">Nature Communications</a>.

"One of the proposed theories to explain the discrete auroral arcs - the most widely known type of the aurora, which appears as bright and undulating curtains of light - involves the acceleration of electrons by Earthward traveling Alfven waves, with a progression of events as follows."

Professor Howes explains that violent events on the Sun, such as solar flares and coronal mass ejections, disturb the flow of the solar wind that moves through the solar system. These disturbances, he says,  can trigger severe geomagnetic storms directed at the Earth, accompanied by some of the most intense auroral displays.

"The dynamics of the geomagnetic storm drives a process called magnetic reconnection in the Earth's distant magnetotail, in which magnetic field lines break and reform, eventually snapping back towards the Earth due to magnetic tension, like a stretched rubber band that is suddenly released." 

"This rebounding of the magnetic field launches Alfven waves that travel Earthward along the magnetic field. At altitudes below about three Earth radii (20,000 km, or 12,000 mi), where Alfven wave speed exceeds the electron thermal velocity, electrons moving in the same direction as the Alfven wave can be efficiently accelerated by the wave to higher speeds." 

The electrons "surf" on the electric field of the Alfven wave, picking up speed from the energy of the wave. This process, known as Landau damping, was first proposed in 1946 by Russian physicist Lev Landau.

In the current study, the experts determined that the accelerated electrons travel at speeds of up to 45 million miles per hour. Streaming down along the Earth's magnetic field, the supercharged electrons collide with oxygen and nitrogen atoms in the thin air of the upper atmosphere. 

"The impact causes these atoms and molecules to emit light, resulting in the glow of the shimmering curtains of light in discrete auroral arcs," explains Professor Howes.

For the investigation, researchers from the University of Iowa collaborated with experts at Wheaton College and UCLA to conduct experiments on the Large Plasma Device (LAPD) at UCLA's Basic Plasma Science Facility. The team replicated the conditions of Earth's auroral magnetosphere in the laboratory.

"The research team used an innovative analysis technique that combines the measurements of the wave's electric field and the electrons to generate a unique signature of the electron acceleration by Landau damping," notes Professor Howes.

"Through numerical simulations and mathematical modeling, they showed that the signature of acceleration measured in the experiment agreed with the predicted signature for Landau damping." 

"The agreement of experiment, simulation, and modeling provides the first direct test showing that Alfven waves produce accelerated electrons that cause auroras."

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Northern lights linked to electrons traveling at millions of miles per hour

The northern lights are created by high-powered electromagnetic waves that...

A growing collection of research suggests that physical activity can delay or prevent the development of Alzheimer's disease. In older adults, aerobic <a href="https://www.earth.com/news/why-do-some-people-benefit-more-from-exercise-than-others/">exercise</a> training improves memory, enhances blood flow, and increases gray and white matter volume.

The ability to measure the effects of exercise on memory biomarkers could advance efforts to prevent Alzheimer's disease or to effectively treat it. However, there is a lack of knowledge on which specific biomarkers can measure the effects of exercise on cognitive function.

To investigate, researchers at the <a href="https://www.fau.edu/">Florida Atlantic University</a> Schmidt College of Medicine and Brain Institute tested the theory that three specific biomarkers associated with learning and memory would increase in older adults following exercise training. The experts also theorized that these biomarkers correlate with cognition and metabolomics markers of brain health. 

The research was focused on myokine Cathepsin B (CTSB), brain derived neurotrophic factor (BDNF), and klotho. The team also used metabolomics, or the large-scale study of metabolites, which has become increasingly utilized to understand biochemical pathways that may be affected by Alzheimer's disease.

The metabolomics analysis was conducted using blood samples of 23 asymptomatic older adults with a genetic risk for Alzheimer's disease. The participants were divided into two groups: usual physical activity (UPA) and enhanced physical activity (EPA). The EPA group participated in 26 weeks of treadmill training. 

Blood samples showed that plasma CTSB levels were increased following the aerobic exercise training. The experts found that learning and memory correlated positively with change in CTSB but was not related to BDNF or klotho. 

The study also revealed that multiple lipid metabolites relevant to Alzheimer's disease were modified by exercise in a manner that may be neuroprotective. "Our findings position CTSB, BDNF, and klotho as exercise biomarkers for evaluating the effect of lifestyle interventions on brain function," said study co-author Dr. Henriette van Praag. 

"Human studies often utilize expensive and low throughput brain imaging analyses that are not practical for large population-wide studies."

"Systemic biomarkers that can measure the effect of exercise interventions on Alzheimer's-related outcomes quickly and at low-cost could be used to inform disease progression and to develop novel therapeutic targets."

After exercise, CTSB is secreted from muscle into circulation and is associated with memory function and adult hippocampal neurogenesis. Older adults with cognitive impairment have lower serum and brain CTSB levels. 

"The positive association between CTSB and cognition, and the substantial modulation of lipid metabolites implicated in dementia, support the beneficial effects of exercise training on brain function and brain health in asymptomatic individuals at risk for Alzheimer's disease," said Dr. van Praag.

The study is published in the journal <a href="https://www.frontiersin.org/journals/endocrinology">Frontiers in Endocrinology</a>.

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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Exercise protects older adults from the onset of Alzheimer's disease

A growing collection of research suggests that physical activity can...

A new study from the <a href="https://www.cam.ac.uk/">University of Cambridge</a> describes how plants get an early start to their day, bursting with activity just after dawn. While it was known that gene activity peaks at sunrise in plants, the experts wanted to gain a better understanding of what controls this peak. 

Early morning light plays an important role in coordinating circadian rhythm and various growth processes in plants. By staying aligned with day-night cycles, plants can control the timing of their day, such as when to open flowers for pollinators or make the best use of sunlight.

Within an hour of dawn, plant genes that control light, stress, and growth hormones become strongly active. To investigate this genetic activity, the researchers focused on the small flowering plant thale cress, collecting samples every two minutes from dawn to measure gene expression.

"We set out to characterize 'dawn burst' dynamics in more detail, focusing on the expression of transcription factor genes. We found three distinct gene expression waves within two hours after dawn. The first of these occurs just 16 minutes after dawn and lasts only 8 minutes," explained study first author Dr. Martin Balcerowicz.

"Many of these genes are known to be sensitive to light and temperature, but we wanted to find out specifically how the transcription of these genes is coordinated." 

"Interfering in photoreceptor signaling, the circadian clock and chloroplast derived light signals did cause problems in some genes' expression, but there was a large proportion of genes still unaffected. This indicated to us that some of the upstream pathways are redundant and that additional regulators are in play."

The team ultimately identified a network that regulates genes at dawn, with two key regulators of light signaling - HY5 and BBX31. These genes appeared to play a central role during the dark-to-light transition at dawn.

"In fact, multiple BBX genes form part of the dawn burst alongside BBX31, HY5 and its homologue HYH," said Dr Balcerowicz. "These genes include both positive and negative regulators of the light response. We found that they act downstream of phytochrome and cryptochrome photoreceptors to control a light-induced subset of dawn burst genes, with HY5 and BBX31 having largely antagonistic roles."

"This observation strengthens the idea that HY5 and BBX genes act in concert to fine-tune light responses in the context of the day-night cycle."

Study senior author Dr. Daphne Ezer is a lecturer in Computational Biology at the University of York who investigates gene-environment interactions through the analysis of gene networks. 

"By studying gene networks we can interpret how plants integrate light and temperature signals in the early morning to entrain the circadian clock," explained Dr. Ezer. 

"Taken together, our results show that phytochrome and cryptochrome signaling is required for fine-tuning the dawn transcriptional response to light, but separate pathways can robustly activate much of the programme in their absence."

"Characterizing the peak we see in gene expression that results from the onset of light is useful in helping us to understand how plants respond to light and, in particular, for crops grown under artificial lighting, how this dawn burst impacts longer term on growth."

The study is published in the journal <a href="https://www.cell.com/molecular-plant/home">Molecular Plant</a>.

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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Study reveals why plants have a burst of activity at dawn

A new study from the University of Cambridge describes how...

The main ice shelf that stabilizes the Pine Island Glacier is tearing away, which means the <a href="https://www.earth.com/news/doomsday-glacier-exposed-to-more-warm-water-than-expected/">glacier</a> will likely collapse into the ocean sooner than expected, according to a new study from the <a href="https://www.washington.edu/">University of Washington</a>.

"We may not have the luxury of waiting for slow changes on Pine Island; things could actually go much quicker than expected," said study lead author Ian Joughin, a glaciologist at the UW Applied Physics Laboratory. 

"The processes we'd been studying in this region were leading to an irreversible collapse, but at a fairly measured pace. Things could be much more abrupt if we lose the rest of that ice shelf."

The ice held in the Pine Island Glacier is estimated at approximately 180 trillion tons. This is the equivalent of 1.6 feet of global sea level rise. The glacier is already responsible for much of Antarctica's contribution to rising sea levels. 

Copernicus Sentinel-1 satellite images revealed that Pine Island's ice shelf lost one-fifth of its area in a few dramatic breaks from 2017 to 2020. When the researchers analyzed images from 2015 to 2020, they determined that recent changes on the ice shelf were not directly caused by melting.

"The ice shelf appears to be ripping itself apart due to the glacier's acceleration in the past decade or two," explained Joughin. The team found that two points on the glacier's surface sped up by 12 percent between 2017 and 2020. 

"The recent changes in speed are not due to melt-driven thinning; instead they're due to the loss of the outer part of the ice shelf," said Joughin. "The glacier's speedup is not catastrophic at this point. But if the rest of that ice shelf breaks up and goes away then this glacier could speed up quite a lot."

Joughin noted that other factors will influence whether the shelf will continue to crumble, such as the slope of the land below the glacier's receding edge. 

"The loss of Pine Island's ice shelf now looks like it possibly could occur in the next decade or two, as opposed to the melt-driven subsurface change playing out over 100 or more years," said study co-author Pierre Dutrieux, an ocean physicist at British Antarctic Survey. "So it's a potentially much more rapid and abrupt change."

"Sediment records in front of and beneath the Pine Island ice shelf indicate that the glacier front has remained relatively stable over a few thousand years. Regular advance and break-ups happened at approximately the same location until 2017, and then successively worsened each year until 2020."

The study is published in the journal <a href="https://advances.sciencemag.org/">Science Advances</a>.

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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Pine Island Glacier will collapse sooner than expected

The main ice shelf that stabilizes the Pine Island Glacier...

Some butterflies and <a href="https://www.earth.com/news/butterflies-and-moths-are-struggling-to-adapt-to-climate-change/">moths</a> have achieved the ultimate self-defense mechanism. Species like the glasswing butterfly, Greta oto, have evolved transparent wings that make them nearly invisible to predators.

A team of scientists led by the <a href="https://www.mbl.edu/">Marine Biological Laboratory</a> (MBL) set out to investigate how transparent structures, which are far more common in marine animals, developed in the glasswing butterfly.

"It's an interesting biological question because there just aren't that many transparent organisms on land," said study lead author Aaron Pomerantz, a PhD candidate at UC Berkeley. "So we asked the question, what is the actual developmental basis of how they create their transparent wings?"

The colorful patterns found on butterfly wings are created by tiny chitinous scales that reflect or absorb various wavelengths of light. 

Pomerantz explained that although scale coloration has been intensively studied, investigating the developmental origins of transparency in land-based butterflies hadn't been done before. "Transparency is sort of the opposite of color."

The current research was inspired by the work of students in MBL's Embryology course, which is taught by study co-author MBL Director Nipam Patel.

"I decided to bring some of the transparent butterfly and moth species I had in my collection, which I never really looked at in detail, to the course and present it as a challenge for the students to look at how these wings were transparent," said Patel.

"A group of students took that on by imaging the wings with various microscopes. And they realized that pretty much any way you could think to make the wing transparent, some butterfly or moth had figured out how to do it. That's what got us looking in more detail at the development of transparency."

The team used an advanced electron microscopy technique to construct a developmental time scale of how transparency emerged in the glasswing butterfly from the pupal stage to adulthood. 

The study revealed that the glasswing butterfly's wings do not develop in the same way as other opaque species. 

"What Greta oto does is to make fewer scales and to make them in these very different, bristle-like shapes," explained Patel. "But getting the scales out of the way is only part of the problem of creating transparency." 

"Aaron also made a series of observations about nanostructures on the wing that prevent glare in bright sunlight. When light hits these little arrays of nanostructures, it doesn't reflect off - it goes straight through. So that gives much better transparency."

"As humans, we think we're so brilliant because we figured out how to put anti-glare coating on glass, but butterflies basically figured that out tens of millions of years ago."

Beyond their unusual wing scales, the experts identified a second layer of waxy hydrocarbon nanopillars over the wing surface that enhance the anti-reflective properties. The researchers removed this waxy layer to compare the reflectivity of the wings with and without it. 

"We measured the amount of light that reflected off the wing," said Pomerantz. "Those experiments demonstrated that that upper layer was very important for helping to reduce that glare." 

Further research is needed to explore how these remarkable transparent structures evolved. Pomerantz noted that learning more about how nature creates new types of nanostructures could be very informative for human applications.

The study is published in the <a href="https://journals.biologists.com/jeb">Journal of Experimental Biology</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

The glasswing butterfly has a unique type of transparency

Some butterflies and moths have achieved the ultimate self-defense mechanism....

Sweet Pittosporum is a fast-growing <a href="https://www.earth.com/news/ghost-forests-release-greenhouse-gas-emissions-in-tree-farts/">tree</a> that has become invasive in parts of Australia where it is not indigenous. The tree almost completely extinguishes the surrounding vegetation, but experts report that clearing the trees could allow this native vegetation to return.

In a new study from <a href="https://www.monash.edu/">Monash University</a>, scientists have investigated how clearing Pittosporum trees may affect birds such as the threatened Powerful Owl. The researchers found that the richness and abundance of birds is greatly reduced in areas with dense Pittosporum canopies.

"The almost complete absence of any understory vegetation and no ground cover means there is very little for birds to eat in invaded sites," said study lead author Dr. Ben O'Leary.

"Most habitat components for birds exists within the Eucalyptus overstorey and mid canopy. The presence or removal of Pittosporum doesn't appear to greatly influence ground storey bird species, which have been in long-term decline."

The study also showed that there are also fewer carnivorous birds in sites that have been invaded by Pittosporum trees, which is likely due to the lack of vegetation and prey on the ground.

"While invaded sites are not great habitat, restoration projects need to ensure that the full range of habitats continue to be available during the transition period," said Dr. O'Leary.

The removal of an invasive tree species without affecting other wildlife can be a challenge. In certain circumstances, the trees provide structural value to local flora and fauna. 

"The trick is balancing the progression of weed control with the retention of enough structure to support local plants and animals," said Dr. O'Leary.

Study co-author Ros Gleadow is a professor in the School of Biological Sciences who has been studying Pittosporum for over 40 years.

"It is important to get rid of the Pittosporum now," said Professor Gleadow. "Not only does it suppress the understorey, but in all these years, I have never seen a eucalypt seedling growing under a Pittosporum canopy."

"Once the old eucalypts at a site die, that's it and it of both native vegetation and birds is impossible without major intervention."

"For areas where Pittosporum is native, like around Sydney, management is philosophically complicated but there is no doubt that clearing will to help preserve biodiversity."

The study is published in the journal <a href="https://besjournals.onlinelibrary.wiley.com/journal/26888319">Ecological Solutions and Evidence</a>.

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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Invasive Pittosporum trees are destroying owl habitats

Sweet Pittosporum is a fast-growing tree that has become invasive...

Arctic coastal sea ice is thinning at double the rate that was expected, according to a new study from the <a href="http://www.esa.int/">European Space Agency</a>. The researchers analyzed ice-thickness data from the CryoSat and Envisat missions, while using a new model to estimate snow depth. 

The CryoSat altimeter measures ice height by timing how long it takes for radar waves to return to the satellite from the ice surface. 

The thickness of floating sea ice is determined by measuring the height of the ice above the water. But these measurements are not always reliable when heavy snow is pushing the ice down into the water. 

To overcome this challenge, the researchers used a new computer model that calculates snow depth and density. The team then combined the snow model projections with radar observations. 

Robbie Mallett is a PhD student at the Centre for Polar Observation and Modeling (CPOM) at University College London.

“The thickness of sea ice is a sensitive indicator of the health of the Arctic. It is important as thicker ice acts as an insulating blanket, stopping the ocean from warming up the atmosphere in winter, and protecting the ocean from the sunshine in summer. Thinner ice is also less likely to survive during the Arctic summer melt," said Mallett.

“Previous calculations of sea-ice thickness are based on a snow map that was last updated 20 years ago. Because sea ice has begun forming later and later in the year, the snow on top has less time to accumulate. Our calculations account for this declining snow depth for the first time, and suggest the sea ice is thinning faster than we thought.”

The researchers concluded that sea ice in Arctic coastal regions is thinning at a rate of 70 to 100 percent faster than previously thought. 

For example, ice is thinning in the coastal regions of the Kara and Chukchi seas at a rate of up to 110 percent higher than previous calculations.

“There are a number of uncertainties in measuring sea-ice thickness, but we believe our new calculations are a major step forward in terms of more accurately interpreting the data we have from satellites," said Professor Julienne Stroeve.

“We hope this work can be used to better assess the performance of climate models that forecast the effects of long-term climate change in the Arctic - a region that is warming at three times the global rate, and whose millions of square kilometres of ice are essential for keeping the planet cool.”

The study is published in the journal <a href="https://tc.copernicus.org/">The Cryosphere</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Coastal sea ice is thinning much faster than expected

Arctic coastal sea ice is thinning at double the rate...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Flu viruses are more flexible than expected

[sendtonews key="G9bUoxcjr4-2511624-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Detecting mercury contamination with the tap of a finger

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Kainji Lake, a reservoir on the Niger River.



In 1968, Kainji Lake was created by the construction of the Kainji Dam. The Niger River, the third longest in Africa, enters the lake in the north.&nbsp;



According to <a href="https://www.earth.com/news/rivers-in-the-american-west-are-a-lifesaving-resource-for-birds/">ESA</a>, the creation of the lake submerged Foge Island and the town of Bussa and permanently flooded other riverine settlements, leaving around 50,000 people displaced.&nbsp;



Large parts of Foge Island are temporarily exposed during low water tides, and the land is often used by migrating fishermen. Kainji Dam is a dam across the Niger River in Niger State of Central Nigeria. 



Wild mammals occur at relatively low densities due to illegal hunting. Lake Kainji has suffered a dramatic decline as a fishery due to the high numbers of artisanal and subsistence fisherfolk using the lake. It has been suggested that a period of closure, together with controlled fishing rights may help improve fish stocks.



Kainji Lake National Park is the oldest of its kind in Nigeria. The park contains three distinct areas: a part of the Kainji Lake, the Borgu Game Reserve to the west of the lake, and the Zugurma Game Reserve to the southeast. The park is home to around 65 mammal species, 350 bird species, and 30 species of reptiles and amphibians. 



Video/ Image Credit: European Space Agency&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Kainji Lake in north central Nigeria

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Today’s Video of the Day from <a href="https://www.igb.illinois.edu/">Carl R. Woese Institute for Genomic Biology</a> reveals how scientists can modify common crops like soybean, rice, and wheat to protect them from heat stress.



“We need to double crop production by 2050 to feed a growing global population, and not only are we not on track to do that, but climate change is further complicating things,” said Amanda Cavanagh, a lecturer at the University of Essex. 



The study is part of Realizing Increased Photosynthetic Efficiency (RIPE), an international research project that aims to develop food crops that turn the sun’s energy into food more efficiently.



“Using an engineering approach we designed multiple alternative metabolic pathways to photorespiration. Testing them in the field showed increases in productivity which led Amanda to significantly move the project forward by showing our engineered plants can withstand pretty extreme temperature stress,” said study co-author and RIPE researcher Paul South.&nbsp;



“As the climate changes and temperature stresses increase the pressure on our global food supply, farmers will need every tool available including engineering approaches like the synthetic biology used here to maintain safe and productive harvests.”



The experts tested plants modified to have more efficient photorespiration to see if they were better adapted to warmer temperatures.&nbsp;



The team found that the engineered plants produced 26 percent more biomass than the wild-type plants exposed to the same temperatures, and had 15 percent less yield loss under the higher temperatures.



Video Credit: Amanda Nguyen/University of Illinois



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Designing crops that can beat the heat

[sendtonews key="QGPzYnXEtN-1712599-12187" type="single"] Today’s Video of the Day from Carl...

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

How does salt makes things taste better?

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Santiago, Chile in South America

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Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Interactive map of the universe includes 200,000 galaxies

[sendtonews key="e4ZG0Jawp3-2374785-12187" type="single"] Astronomers at Johns Hopkins University have created...

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes the first comprehensive estimate of carbon density in the Saharan, Sahel, and Sudanian zones of Africa. In an effort to measure the amount of carbon stored across these drylands, a team of scientists used high-resolution satellite images and artificial intelligence to map nearly 10 billion individual trees. 



"The high spatial resolution (50 cm) combined with AI and field measurements used in this study is key to improving tree inventories in drylands," said Pierre Hiernaux, a French researcher working for NASA. "The ever-increasing availability of very high-resolution satellite imagery will make it possible to assess carbon pools and their dynamics at the individual tree level on a global scale."



"This study is exceptional because it is pioneering a type of approach that will revolutionize the monitoring of trees and forests on a global scale: in the short term, it will be possible to map the world's trees from the centre of the Amazon to our schoolyards," said <a href="https://www.inrae.fr/en">INRAE</a> researcher Jean-Pierre Wigneron.



"Many fields of application will become much more efficient and accurate, such as tracking carbon stocks, biodiversity, monitoring logging and protection against illegal forest degradation, in near real time.”



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Remote sensing will revolutionize the way we monitor trees

[sendtonews key="EjmSP20gQK-2593093-12187" type="single"] Today's Video of the Day from NASA...

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The province of Zaragoza in northeast Spain

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> features a visual dataset of.methane emissions from wetlands across the globe. Atmospheric methane levels have reached record highs in recent years, and wetlands are a major source of these emissions.&nbsp;



"Methane is an important greenhouse gas that contributes substantially to global warming. On a molecule by molecule basis, methane is much more efficient at trapping heat than carbon dioxide, the main driver of warming," says NASA.



"Though human activities, including agriculture, oil and natural gas production and use, and waste disposal, collectively contribute the majority of methane to the atmosphere, about a third of total methane emissions comes from wetlands."&nbsp;



According to NASA, understanding methane emissions from wetlands and other natural sources is critically important for scientists and policymakers who are working to combat climate change by reducing emissions from human activities.



Video Credit: NASA Goddard



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Wetlands are a major source of methane emissions

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The rapid retreat of the Columbia Glacier

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The Pyrenees Mountains in southwest Europe

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Today’s Video of the Day from <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes why experts are studying zebrafish to gain a better understanding of how the immune system responds to injury. Zebrafish have the ability to repair and regenerate organs.



“Organ regeneration offers an exciting opportunity for studying the immune system and to inquire why some species can regenerate organs like the heart or missing limbs while others like humans cannot,” explained Dr. Tatjana Piotrowski.



Zebrafish sensory organ hair cells are an ideal system to investigate the pathways and cell types involved in regeneration since they are easily destroyed with antibiotics and begin regenerating within five hours. This enabled the researchers to identify the exact timing and genetic programs for each anti-inflammatory macrophage activation state.&nbsp;



“Our hypothesis is that human macrophages do not receive the proper chemical activation 'cocktail' to instruct pro-regenerative processes,” said Dr. Nicolas Denans. “Identifying the molecular recipe of macrophage activation in zebrafish may one day enable us to design regenerative immunotherapies in humans.”&nbsp;&nbsp;&nbsp;



“The new evidence is a valuable resource for comparative studies on the genetic programs involved in macrophage-mediated repair and regeneration. In other words, different types of injuries may induce different kinds of inflammatory responses. We want to decipher whether this 'language' is universal or if there are a variety of dialects."



Video Credit: Stowers Institute for Medical Research&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

How the immune system responds to injury

[sendtonews key="0dEcERCq61-2283382-12187" type="single"] Today’s Video of the Day from Stowers...

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes how record-breaking heat expressed itself around the world in 2022.



Scientists have determined that 2022 was the 5th warmest year since 1880. Furthermore, the last nine consecutive years have been the warmest on record.



From devastating floods and wildfires to natural disasters like Hurricane Ian, 2022 showed us yet again how a warming climate affects people across the globe.&nbsp;



"As we look back at 20:22 and years past, we see that each year we better understand the challenges we face and how important it is to meet them," says NASA.



Video/ Image Credit: NASA Goddard



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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2022 illustrated the consequences of a warming climate

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Two distant planets may be "water worlds"

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites reveal how Earth's systems are interconnected

[sendtonews key="JbW4VsY53O-1632195-12187" type="single"] Satellites reveal how Earth's systems are interconnected...

Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...