<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features a large sediment plume from the Yangtze River that extends hundreds of kilometers off the coast of China.</p>



<p>"Brown, sediment-laden water is visible along this shallow, turbid stretch of coast year-round, but a vast plume like the one visible here is a characteristic feature of winter. Scientists have proposed several causes of this seasonal phenomenon," said NASA.</p>



<p>"The ebb and flow of tides contain enough energy to stir up sediments from the seafloor, a 2017 study found. While there are also tides in the summer, the models used in the study showed that sediment only rises to the surface in the winter. That’s when temperatures and salinities at the sea surface and bottom are similar, allowing for vertical mixing to occur and for sediment to churn higher into the water column."</p>



<p>Additional studies have suggested that the summer monsoon’s influence on currents impedes the eastward flow of sediment out of the estuaries, noted NASA.</p>



<p>"Despite what looks like a glut of suspended sediment in the water, the overall amount of it flowing from the Yangtze River has declined steadily over the past several decades. The construction of dams, including the Three Gorges Dam, has been the primary driver of this trend."</p>



<p>It is important for scientists to track the movement of suspended sediment. This material can cause direct harm to marine life, as well as indirect harm by blocking sunlight.</p>



<p>The Yangtze River, also known as the Chang Jiang in Chinese, is the longest river in Asia and the third-longest in the world, following the Nile and the <a href="https://www.earth.com/news/amazon-river-dolphins-are-at-great-risk-of-extinction-due-to-human-activities/">Amazon</a>. It flows for over 6,300 kilometers (about 3,917 miles) from the glaciers of the Qinghai-Tibet Plateau in western China to the East China Sea at Shanghai.&nbsp;</p>



<p>The Yangtze River basin is a key region for China's agriculture, industry, and hydroelectric power production. The river's waters are used for irrigation, navigation, and as a source of freshwater. The basin is home to diverse wildlife, including the critically endangered Yangtze river dolphin or Baiji, which may now be extinct.</p>



<p>The image was captured on February 12, 2024 by the Visible Infrared Imaging Radiometer Suite sensor on the NOAA-20 satellite.</p>



<p>Image Credit: NASA Earth Observatory</p>



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Sediment flows offshore from the Yangtze River 

Today's Image of the Day from NASA Earth Observatory features...

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the Ruki River in the Democratic Republic of the Congo (DRC). It is a tributary of the Congo River, one of the largest <a href="https://www.earth.com/news/warmer-rivers-keep-antimicrobial-resistant-genes-at-bay/">rivers</a> in the world by discharge and depth. </p>



<p>The Ruki River, previously known as the Busira, merges with the Momboyo River near the town of Basankusu to become the Lulonga River, which eventually flows into the Congo River at the town of Lisala.</p>



<p>"If the appearance of the muddy Amazon River evokes a coffee cut with cream, the Ruki River, coursing gently through the Congo Basin, is like a dark tea," said NASA.</p>



<p>"On its slow path through mostly untouched lowland rainforest in the Democratic Republic of Congo (DRC), the water leaches organic material from vegetation, prompting some researchers to think it is one of the darkest blackwater rivers on Earth. The dissolved material in this distinctive water, scientists are finding, offers clues into the carbon cycle of tropical forests."</p>



<p>In a recent study, researchers measured the chemical composition and flow of the Ruki for the first time.&nbsp;</p>



<p>"The study reported that, as the water color suggests, the Ruki is rich in dissolved organic carbon compounds. It contains four times as much organic carbon as the Congo River and 1.5 times as much as the Rio Negro, the world’s largest blackwater river and a major tributary of the Amazon," said NASA.</p>



<p>Due to this heavy carbon load, the researchers concluded that “tropical forests like those around the Ruki might not accumulate quite as much carbon as we once thought.”</p>



<p>The region around the Ruki River is rich in biodiversity, hosting various species of flora and fauna. It is part of the Congo Basin, the second-largest tropical rainforest area in the world, which is a critical habitat for endangered species and a significant carbon sink.</p>



<p>The river is vital for the livelihoods of local communities. Fishing is a crucial activity, with many people depending on it for sustenance and income. The river also supports agriculture along its banks, where communities grow crops.</p>



<p>In many parts of the DRC, rivers like the Ruki are crucial transportation corridors due to the challenging and often nonexistent road infrastructure. The river enables the movement of people and goods, facilitating trade and access to markets, health care, and education.</p>



<p>The region faces several challenges, including deforestation, overfishing, and environmental degradation, which threaten its ecological balance and the livelihoods of people who depend on it. Efforts to manage and conserve the river's resources are vital for sustainable development.</p>



<p>Understanding and protecting the Ruki River and its surroundings are crucial for the DRC's environmental sustainability, economic development, and the well-being of its communities.</p>



<p>The image was captured by the OLI (Operational Land Imager) on Landsat 8.</p>



<p>Image Credit: NASA Earth Observatory&nbsp;</p>



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The Ruki River in the Democratic Republic of the Congo

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> features dust streaming from Lago Colhué Huapi, a shallow endorheic lake located in the Chubut Province in southern Argentina.</p>



<p>"Strong northwesterly winds often race down the eastern side of the Andes Mountains and whip across the central Patagonian Desert. In the process, they sometimes lift dust from Argentina’s drying Lago Colhué Huapi, fueling intense dust storms," said NASA.</p>



<p>"Lago Colhué Huapi is a particularly rich source of dust because the shallow lake regularly grows and shrinks with variations in the flow of the Senguer River and the pace of evaporation. When lake water levels are low, as they were when MODIS captured this image, fine-grained, lightweight particles are easily transported by the wind."</p>



<h2 class="wp-block-heading" id="h-dust-activity-from-lago-colhue-huapi">Dust activity from Lago Colhué Huapi</h2>



<p><a href="https://www.earth.com/news/dust-storms-in-the-gulf-of-alaska-help-shape-the-global-climate/">Dust storms</a> in this region are most common during the summer months from December to March. There are 15 to 30 dust storms in a typical year.&nbsp;</p>



<p>"Dust storms are frequent and persistent enough in this area that they have exposed an open-air archaeological site along the lake’s edge," said NASA.</p>



<p>"The Puesto Roberts 1 site, located in an old floodplain on the southeast side of Lago Colhué Huapi, was first identified in 2019 when archaeologists noticed that winds had exposed a five-centimeter layer of sandy loam soil littered with stone tools and the bones of a wild species of llama called guanaco."</p>



<p>"Archaeologists identified 427 artifacts at the site - including stone cutting blades, milling tools, scrapers, and egg-shaped bola stones used for hunting - spread across 15 square meters, according to a 2022 study led by Heidi Hammond, an archaeologist at the National University of the Patagonia San Juan Bosco."</p>



<h2 class="wp-block-heading" id="h-more-about-lago-colhue-huapi">More about Lago Colhué Huapi</h2>



<p>This lake is an interesting geographical feature primarily because it acts as a seasonal sink for the Senguerr River, which in turn gathers waters from various smaller streams in the region. </p>



<h3 class="wp-block-heading" id="h-size">Size</h3>



<p>Due to its shallow nature, the size of Lago Colhué Huapi can vary significantly with the seasons and the amount of water it receives from its sources. During times of drought or reduced rainfall, the <a href="https://www.earth.com/news/climate-change-is-pushing-lakes-to-their-boiling-point/">lake</a> can shrink considerably, affecting the local ecosystem and the wildlife that depends on it.</p>



<h3 class="wp-block-heading" id="h-climate">Climate</h3>



<p>The lake's surroundings are characterized by a semi-arid climate, which influences the type of vegetation and animal life that can thrive in the area. Despite the harsh conditions, the region around Lago Colhué Huapi supports a variety of bird species, making it a site of interest for birdwatchers and naturalists.</p>



<h3 class="wp-block-heading" id="h-environmental-challenges">Environmental challenges </h3>



<p>In recent years, Lago Colhué Huapi has faced environmental challenges, including the impact of <a href="https://www.earth.com/news/alarming-study-most-of-the-worlds-largest-lakes-are-quickly-losing-water/">climate change</a>, which has led to lower water levels and increased salinity. These changes pose threats to the lake's ecological balance and the species that inhabit its waters and shores. The situation at Lago Colhué Huapi serves as a reminder of the broader environmental issues facing water bodies in arid and semi-arid regions around the world.</p>



<p>The image was captured on March 29, 2024 by the MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA’s Aqua satellite.</p>



<p>Image Credit: NASA Earth Observatory</p>



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Dust streams from Lago Colhué Huapi in Argentina 

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features thick haze over Thailand during the fire season. The photograph was captured by the VIIRS (Visible Infrared Imaging Radiometer Suite) on the Suomi NPP satellite on March 16, 2024.</p>



<h2 class="wp-block-heading" id="h-waves-of-smoke-and-haze">Waves of smoke and haze</h2>



<p>"Each year in January and February, satellites begin to detect waves of smoke and fire in Southeast Asia, particularly in highland forests in Cambodia, Laos, Myanmar, and Thailand. Fire activity continues to increase through March and April, reaches a peak during the height of the dry season, and then fades in May with the start of the rainy season," noted NASA.</p>



<p>"Individual fires are usually small and short-lived. But they are often so numerous that smoke, along with air pollution from rural and urban areas, mixes to produce thick layers of haze that blanket the landscape." </p>



<p>"Such hazes contain mixtures of small airborne particles called aerosols and gaseous pollutants such as nitrogen dioxide, sulfur dioxide, carbon monoxide, and ozone that degrade air quality and have harmful health effects."</p>



<h2 class="wp-block-heading" id="h-haze-in-thailand-nbsp">Haze in Thailand&nbsp;</h2>



<p>An international field campaign - the Airborne and Satellite Investigation of Asian Air Quality (ASIA-AQ) - was recently launched to investigate the haze in Thailand.</p>



<p>"During the last two weeks of March 2024, NASA’s DC-8 and Gulfstream III aircraft flew several flights over Chiang Mai, Bangkok, and rural areas surrounding the cities to sample air quality with several sensors. At the same time, satellites observed the haze from above," said NASA.</p>



<p>James Crawford, ASIA-AQ’s principal investigator, said the team is collaborating closely with national and local government entities in Thailand.</p>



<p>“The goal is to take as many simultaneous measurements of pollutants as possible from the ground, air, and space,” said Crawford. The team will use the data to gain a better understanding of how the haze forms, evolves chemically over time, and moves throughout the region.</p>



<h2 class="wp-block-heading" id="h-haze-and-public-health-in-thailand">Haze and public health in Thailand </h2>



<p>According to media reports, nearly 200,000 people have been hospitalized this year due to air quality in the region, with over 1.3 million people falling ill since January.&nbsp;</p>



<h3 class="wp-block-heading" id="h-root-causes">Root causes</h3>



<p>The root causes of the haze include agricultural burning, particularly of corn fields, as part of slash-and-burn practices to prepare land for the next planting cycle. This is exacerbated by the dry season when there's little rain to wash the pollutants away. </p>



<p>The situation is worsened by industrial emissions and vehicle fumes, particularly in urban areas like Bangkok​.</p>



<h3 class="wp-block-heading" id="h-sustainable-solutions-are-needed">Sustainable solutions are needed</h3>



<p>Efforts to address the crisis have been complex, involving local and transboundary issues. Much of the agricultural burning occurs not only within Thailand but also in neighboring countries like Myanmar and Laos, contributing to the transboundary nature of the haze. </p>



<p>Activists and local communities have called for sustainable solutions that do not exacerbate the poverty of smallholder farmers, emphasizing the need for affordable and realistic alternatives to burning​.</p>



<h3 class="wp-block-heading" id="h-mitigation-measures-nbsp">Mitigation measures&nbsp;</h3>



<p>The Thai government has implemented a no-burning rule until the end of April to combat wildfires and haze, but enforcement and effectiveness remain challenges​​. </p>



<p>Some measures taken to mitigate the immediate effects of pollution in urban areas include spraying water and seeding clouds to encourage rain, although these have had limited success​​.</p>



<p>This ongoing environmental crisis has sparked widespread concern among citizens, who are increasingly using public interest litigation to hold companies and the government accountable for environmental commitments. </p>



<p>With recent political changes, there is hope that the new administration will take more decisive action against the haze, possibly through more stringent regulations and international cooperation​​.</p>



<h2 class="wp-block-heading" id="h-health-impacts-of-haze">Health impacts of haze</h2>



<p>Haze poses several health hazards for those exposed to it, particularly when it contains fine particulate matter (PM2.5). Here are some of the main health risks associated with exposure to haze:</p>



<h3 class="wp-block-heading" id="h-respiratory-problems">Respiratory problems</h3>



<p>Haze can aggravate conditions such as asthma, bronchitis, and other chronic obstructive pulmonary diseases (COPD). The fine <a href="https://www.earth.com/news/heatwaves-and-air-pollution-may-double-fatal-heart-attack-risk/">particles</a> can penetrate deep into the lungs, causing inflammation and reducing lung function.</p>



<h3 class="wp-block-heading" id="h-cardiovascular-issues-and-haze">Cardiovascular issues and haze</h3>



<p>Exposure to fine particulate matter can also affect the cardiovascular system, leading to increased risk of heart attacks, strokes, and high blood pressure. Particles can affect blood vessel function and promote the formation of blood clots.</p>



<h3 class="wp-block-heading" id="h-eye-irritation">Eye irritation</h3>



<p>Haze can cause eye irritation, leading to conditions such as conjunctivitis (pink eye) or exacerbated symptoms in people with existing eye conditions.</p>



<h3 class="wp-block-heading" id="h-skin-problems">Skin problems</h3>



<p>For some people, exposure to <a href="https://www.earth.com/news/air-pollution-will-increase-dramatically-in-a-hotter-climate/">polluted air</a> can cause skin irritation or exacerbate skin conditions like eczema or psoriasis.</p>



<h3 class="wp-block-heading" id="h-reduced-immune-function">Reduced immune function</h3>



<p>There is evidence to suggest that prolonged exposure to polluted air can weaken the immune system, making individuals more susceptible to infections.</p>



<h3 class="wp-block-heading" id="h-impact-on-mental-health">Impact on mental health</h3>



<p>There are growing concerns about the impact of air pollution on <a href="https://www.earth.com/news/air-pollution-linked-to-multiple-chronic-health-conditions/">mental health</a>, with studies suggesting a link between exposure to polluted air and an increased risk of depression and anxiety.</p>



<h3 class="wp-block-heading" id="h-pregnant-women-and-children">Pregnant women and children</h3>



<p>Pregnant women, children, and the elderly are particularly vulnerable to the effects of haze. There may be increased risks of preterm birth and low birth weight in babies, and children may experience delayed development and reduced lung function.</p>



<p>The health impacts of haze can be mitigated by staying indoors on days when air quality is particularly poor, using air purifiers, wearing masks designed to filter out fine particles, and following local health advisories.</p>



<p>Image Credit: NASA Earth Observatory</p>



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<h3 class="wp-block-heading" id="h-nbsp">&nbsp;</h3>

Haze pollution is an environmental crisis in Thailand

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the delta of the Ebro River on the northeast coast of Spain, captured by the Copernicus Sentinel-2 mission.</p>



<h2 class="wp-block-heading" id="h-ebro-river">Ebro River</h2>



<p>“Stretching across 910 km of northern Spain, the Ebro River is the second-longest river in the Iberian Peninsula. In the image, it can be seen as a green line winding its way through the peninsula before flowing into the Mediterranean, shaping the Ebro Delta,” noted ESA.</p>



<p>“The Ebro River discharges more water into the sea than any other river in Spain. As suspended sediment flows from the river’s mouth, it tints the coastal waters with a turquoise hue.”</p>



<h2 class="wp-block-heading" id="h-ebro-delta">Ebro Delta</h2>



<p>The Ebro Delta is one of the largest <a href="https://www.earth.com/news/wetland-methane-emissions-have-surged-at-high-latitudes/">wetland areas</a> in the western Mediterranean region. The river's basin is the largest in Spain, covering about 85,000 square kilometers.</p>



<h2 class="wp-block-heading" id="h-historical-significance-nbsp">Historical significance&nbsp;</h2>



<p>Historically, the Ebro River has been significant in numerous battles, including the famous Battle of the Ebro during the Spanish Civil War, which was one of the war's longest and deadliest conflicts.&nbsp;</p>



<h2 class="wp-block-heading" id="h-economic-significance-nbsp">Economic significance&nbsp;</h2>



<p>Economically, the Ebro plays a crucial role in agriculture, particularly in regions like La Rioja and Navarre, which are known for their vineyards. Additionally, the river supports various industries and hydroelectric power generation.</p>



<h2 class="wp-block-heading" id="h-ecological-significance">Ecological significance</h2>



<p>The Ebro Delta is ecologically rich, providing habitat for diverse bird species. It is also a vital area for rice cultivation in Spain.&nbsp;</p>



<h3 class="wp-block-heading" id="h-nature-reserve">Nature reserve</h3>



<p>“Most of the delta comprises the Ebro Delta Nature Reserve. With its protected wetlands, beaches, marshes, salt pans and estuaries, this reserve provides a natural habitat for numerous migratory birds and waterfowl,” said ESA.</p>



<h3 class="wp-block-heading" id="h-environmental-challenges-nbsp">Environmental challenges&nbsp;</h3>



<p>The river and its delta face environmental challenges such as pollution, water extraction for irrigation, and the impacts of <a href="https://www.earth.com/news/climate-change-may-have-altered-river-flow-worldwide/">climate change</a>, which threaten its ecosystem and the sustainability of its water resources.</p>



<h2 class="wp-block-heading" id="h-the-northeast-coast-of-spain">The northeast coast of Spain</h2>



<p>The northeast coast of Spain is a vibrant and diverse region, characterized by its rich history, unique culture, and stunning landscapes. </p>



<p>It includes the autonomous communities of Catalonia, which features the dynamic city of Barcelona, and part of the Valencian Community. This area is also part of what is known as the Costa Brava, which stretches from the town of Blanes up to the French border.</p>



<h3 class="wp-block-heading" id="h-geography">Geography</h3>



<p>The <a href="https://www.earth.com/news/human-activity-impacts-97-percent-of-the-worlds-coastline/">coastline</a> is renowned for its rugged beauty, with rocky cliffs, secluded coves, and small beaches. The interior regions feature mountains such as the Pyrenees, which offer skiing in winter and hiking in the summer.</p>



<h3 class="wp-block-heading" id="h-cultural-heritage">Cultural heritage</h3>



<p>The area has a strong cultural identity, particularly in Catalonia, where there is a significant movement for independence. The Catalan language is widely spoken alongside Spanish. The region is also known for its festivals, architecture (notably the works of Antoni Gaudí in Barcelona), and traditional dances like the Sardana.</p>



<h3 class="wp-block-heading" id="h-cuisine">Cuisine</h3>



<p>The cuisine is a delightful mix of fresh seafood from the Mediterranean, traditional Catalan dishes like "pa amb tomàquet" (bread with tomato), and rice dishes such as paella in the Valencian region. The area is also famous for its wines, including the sparkling wine Cava.</p>



<h3 class="wp-block-heading" id="h-tourism">Tourism</h3>



<p>The northeast coast attracts millions of tourists each year due to its beautiful beaches, historical sites, and vibrant cities. Barcelona, in particular, is a major tourist destination with attractions like the Sagrada Familia, Park Güell, and the bustling La Rambla.</p>



<h3 class="wp-block-heading" id="h-economy">Economy</h3>



<p>The economy of the northeast coast is one of the most dynamic in Spain, with Barcelona serving as a major hub for trade, education, entertainment, and technology.</p>



<p>Image Credit: NASA Earth Observatory</p>



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The Ebro River on the northeast coast of Spain

<p>Have you ever wondered what secrets lie hidden in the Sun's atmosphere? Scientists have been puzzled by a <a href="https://www.earth.com/wp-content/uploads/2024/04/sun-moss_nasa-TRACE-mission_1m.jpg" target="_blank" rel="noreferrer noopener">peculiar structure</a> on the Sun that they've dubbed "moss" due to its resemblance to the earthly plants. </p>



<p>This bright, patchy plasma formation has been a mystery for decades, but recent research is shedding light on its superheating mechanism.</p>



<h2 class="wp-block-heading" id="h-discovering-the-sun-s-moss">Discovering the Sun's moss</h2>



<p>Souvik Bose, a research scientist at Lockheed Martin <a href="https://www.lmsal.com/" target="_blank" rel="noreferrer noopener">Solar and Astrophysics Laboratory</a> and <a href="https://baeri.org/" target="_blank" rel="noreferrer noopener">Bay Area Environmental Institute</a>, NASA's <a href="https://www.nasa.gov/ames/" target="_blank" rel="noreferrer noopener">Ames Research Center</a> in California's Silicon Valley, and his team have made significant progress in understanding the "moss" on the Sun.</p>



<p>First identified in 1999 by NASA's <a href="https://science.nasa.gov/mission/trace/" target="_blank" rel="noreferrer noopener">TRACE mission</a>, this structure is found around the center of sunspot groups, where magnetic conditions are strong. It spans two atmospheric layers, the chromosphere and corona, and lies beneath the feathery ropes of plasma known as coronal loops.</p>



<h2 class="wp-block-heading" id="h-sunspot-groups-dark-regions-on-the-sun-s-surface">Sunspot groups: Dark regions on the Sun's surface</h2>



<p>Sunspot groups are areas on the Sun's surface that appear darker than their surroundings due to their lower temperatures. These fascinating features have captivated astronomers for centuries and play a crucial role in our understanding of solar activity and its impact on Earth.</p>



<h3 class="wp-block-heading" id="h-formation-and-structure">Formation and structure</h3>



<p><a href="https://www.earth.com/news/giant-sunspot-may-soon-disrupt-earths-power-grids/" target="_blank" rel="noreferrer noopener">Sunspots</a> form when intense magnetic fields emerge from the Sun's interior and pierce through its surface. These magnetic fields inhibit the upward flow of hot gases from below, causing the affected areas to cool down and appear darker. Sunspots typically develop in pairs or groups, with each spot having opposite magnetic polarities.</p>



<p>Within a sunspot group, the largest and most dominant spot is called the "leader," while the smaller spots are known as "followers." The leader spot usually appears first and is located closer to the Sun's equator, while the followers trail behind and are positioned at higher latitudes.</p>



<h3 class="wp-block-heading" id="h-sun-moss-and-the-sunspot-cycle">Sun moss and the sunspot cycle</h3>



<p>Sunspot groups are not static features; they evolve and change over time. The number and size of sunspot groups on the Sun's surface vary in a periodic manner known as the <a href="https://www.earth.com/news/giant-sunspot-may-soon-disrupt-earths-power-grids/" target="_blank" rel="noreferrer noopener">sunspot cycle</a>, which lasts approximately 11 years. </p>



<p>During the peak of the cycle, known as the solar maximum, the Sun exhibits a higher number of sunspot groups and increased solar activity. Conversely, during the solar minimum, sunspot groups are less frequent, and the Sun is relatively calm.</p>



<h3 class="wp-block-heading" id="h-impact-on-solar-activity">Impact on solar activity</h3>



<p>Sunspot groups are often associated with intense solar activity, such as solar flares and coronal mass ejections (<a href="https://www.earth.com/news/massive-solar-outburst-detected-simultaneously-at-earth-the-moon-and-mars/" target="_blank" rel="noreferrer noopener">CMEs</a>). These events occur when the magnetic fields in and around sunspots become entangled and release a tremendous amount of energy. </p>



<p><a href="https://www.earth.com/news/geomagnetic-disturbances-throw-nocturnal-birds-off-course/" target="_blank" rel="noreferrer noopener">Solar flares</a> and CMEs can have significant impacts on Earth, including disrupting satellite communications, affecting power grids, and triggering beautiful auroral displays.</p>



<p>Astronomers monitor sunspot groups using various ground-based and space-based observatories. The Solar and Heliospheric Observatory (<a href="https://soho.nascom.nasa.gov/" target="_blank" rel="noreferrer noopener">SOHO</a>), a joint mission between <a href="https://www.nasa.gov" target="_blank" rel="noreferrer noopener">NASA</a> and <a href="https://www.esa.int" target="_blank" rel="noreferrer noopener">ESA</a>, provides continuous observations of the Sun and helps scientists track the development and evolution of sunspot groups.</p>



<p>Ground-based solar telescopes, such as the <a href="https://noirlab.edu/public/programs/kitt-peak-national-observatory/mcmath-pierce-solar-telescope/" target="_blank" rel="noreferrer noopener">McMath-Pierce Solar Telescope</a> in Arizona and the <a href="https://www.iac.es/en/observatorios-de-canarias/telescopes-and-experiments/swedish-solar-telescope" target="_blank" rel="noreferrer noopener">Swedish Solar Telescope</a> in La Palma, offer detailed views of sunspot groups and their intricate structures.</p>



<h2 class="wp-block-heading" id="h-sun-moss-heating-enigma">Sun moss heating enigma</h2>



<p>One of the biggest challenges scientists have faced is understanding how the mossy region is connected to the Sun's lower <a href="https://www.earth.com/news/for-the-very-first-time-a-spacecraft-has-touched-the-sun/" target="_blank" rel="noreferrer noopener">atmospheric layers</a>. </p>



<p>In addition, how is the material there heated from 10,000 degrees Fahrenheit to nearly 1 million degrees Fahrenheit -- a staggering 100 times hotter than the bright surface below? This heating mechanism has been a puzzle for the past quarter of a century.</p>



<p>Thanks to observations from NASA's High Resolution Coronal Imager (<a href="https://www.nasa.gov/soundingrockets/" target="_blank" rel="noreferrer noopener">Hi-C</a>) sounding rocket and the Interface Region Imaging Spectrograph (<a href="https://science.nasa.gov/mission/iris/" target="_blank" rel="noreferrer noopener">IRIS</a>) mission, combined with complex 3D simulations, scientists have gained new insights into the superheating mechanism at play in the moss.</p>



<p>"Thanks to the high-resolution observations and our advanced numerical simulations, we're able to figure out part of this mystery that's stumped us for the past quarter of a century," said Bose. "However, this is just a piece of the puzzle; it doesn't solve the whole problem."</p>



<h2 class="wp-block-heading" id="h-role-of-electrical-currents">Role of electrical currents</h2>



<p>The research team discovered that electrical currents may contribute to heating the moss. Throughout this region, there is a tangle of magnetic field lines, like invisible spaghetti. </p>



<p>This mess of magnetic spaghetti creates electrical currents that can help heat material to a wide range of temperatures, from 10,000 to 1 million degrees Fahrenheit. </p>



<p>The local heating in the moss appears to occur in addition to heat flowing from the hot, multi-million-degree overlying corona.</p>



<h2 class="wp-block-heading" id="h-implications-for-understanding-the-sun-s-corona">Implications for understanding the Sun's corona</h2>



<p>The findings, published in the journal <em>Nature Astronom</em>y, can help scientists understand the larger question of why the Sun's entire <a href="https://www.earth.com/image/total-solar-eclipse-captured-from-one-million-miles-away/" target="_blank" rel="noreferrer noopener">corona</a> is so much hotter than the surface. However, to fully address how the corona and moss are heated, more observations are needed.</p>



<p>Hi-C is scheduled to launch again this month to capture a solar flare and possibly another moss region together with IRIS. </p>



<p>Scientists and engineers are also working on developing new instruments onboard the future MUlti-slit Solar Explorer (<a href="https://science.nasa.gov/mission/muse/" target="_blank" rel="noreferrer noopener">MUSE</a>) mission to further investigate this fascinating phenomenon.</p>



<h2 class="wp-block-heading" id="h-sun-moss-and-the-future-of-solar-research">Sun moss and the future of solar research</h2>



<p>In summary, as scientists continue to unravel the mysteries of the Sun's atmosphere, the discovery of electrical currents contributing to the superheating of solar moss marks a significant milestone. </p>



<p>This breakthrough, made possible by advanced observations and complex simulations, brings us one step closer to understanding the perplexing heating mechanism of the Sun's corona. </p>



<p>With upcoming missions like Hi-C and MUSE, researchers are poised to delve deeper into the secrets of the solar moss and its role in the larger puzzle of the Sun's atmospheric heating. </p>



<p>As we eagerly await further revelations, this fascinating cosmic garden reminds us that even the most familiar celestial object still holds countless mysteries waiting to be explored.</p>



<p>The full study was published in the journal <em><a href="https://www.nature.com/articles/s41550-024-02241-8" target="_blank" rel="noreferrer noopener">Nature Astronomy</a></em>.</p>



<p>-----</p>



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The Sun is covered with moss, though not the kind you’re thinking

Have you ever wondered what secrets lie hidden in the...

Spirobranchus,Giganteus,,Christmas,Tree,Worms,Extended,On,Caribbean,Coral,Reef

<p>Individual behaviors and rhythms in even the simplest marine creatures, like the polychaete worm <em>Platynereis dumerilii</em>, have been captivatingly showcased in a recent study. </p>



<p>Published in the journal <em>PLOS Biology</em>, this research was carried out by an international team from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (<a href="https://www.awi.de/" target="_blank" rel="noreferrer noopener">AWI</a>), and various universities.</p>



<p>The findings offer profound implications for our understanding of <a href="https://www.earth.com/news/circadian-rhythms-persist-during-bear-hibernation/" target="_blank" rel="noreferrer noopener">biological rhythms</a> and their applications in both medicine and ecology.</p>



<h2 class="wp-block-heading" id="h-platynereis-dumerilii"><em>Platynereis dumerilii</em></h2>



<p><em>Platynereis dumerilii</em>, often referred to as a ragworm or clam worm, is a species of <a href="https://www.earth.com/wp-content/uploads/2024/04/Platynereis-dumerilii-worms_Alfred-Wegener-Institute_1m.jpg" target="_blank" rel="noreferrer noopener">marine polychaete worm</a> found in temperate and tropical coastal waters worldwide. </p>



<p>This worm is particularly interesting to scientists because of its well-defined life cycle and relatively simple nervous system, making it an excellent model organism for biological studies.</p>



<h3 class="wp-block-heading" id="h-key-characteristics">Key characteristics</h3>



<ul>
<li><strong>Size and Appearance:</strong> <em>Platynereis dumerilii</em> is typically a few centimeters long, with a segmented body and a pair of distinctive, paddle-like parapodia on most segments, which aid in swimming.</li>
</ul>



<ul>
<li><strong>Habitat:</strong> These worms thrive in shallow marine environments, often burying themselves in sediments or hiding in crevices during the day and becoming more active at night.</li>
</ul>



<ul>
<li><strong>Reproduction:</strong> They have a fascinating reproductive behavior known as "swarming," where mature individuals synchronously release eggs and sperm into the water column, often influenced by the lunar cycle.</li>
</ul>



<h3 class="wp-block-heading" id="h-scientific-importance">Scientific importance</h3>



<p><em>Platynereis dumerilii</em> is widely used in research related to developmental biology, neurobiology, and evolutionary biology. </p>



<p>Studies on this <a href="https://www.earth.com/news/even-teenage-worms-angsty/" target="_blank" rel="noreferrer noopener">worms</a> help scientists understand basic biological processes such as circadian and lunar <a href="https://www.earth.com/news/how-moonlight-affects-the-circadian-clocks-of-animals/" target="_blank" rel="noreferrer noopener">rhythms</a>, which are applicable to other species, including humans. </p>



<p>This research can have implications for medicine, particularly in understanding body clocks and their effects on health.</p>



<h2 class="wp-block-heading" id="h-platynereis-dumerilii-biological-timing"><em>Platynereis dumerilii</em> biological timing</h2>



<p>Kristin Tessmar-Raible, a biologist at AWI, explains the importance of timing in biology. She states, "Biological timing is crucial across multiple levels, from the ecological interactions between species to cellular biochemical processes."</p>



<p>This study primarily focused on understanding how these worms' internal clocks help them adapt daily. It examined their responses to changing conditions such as temperature, light, and food availability.</p>



<p>The implications are vast, as Sören Häfker, the study's lead author, points out. This is especially true as marine organisms face challenges from human-induced changes such as global warming and light pollution.</p>



<h2 class="wp-block-heading" id="h-a-spectrum-of-behaviors">A spectrum of behaviors</h2>



<p>During the experiments, researchers observed distinct patterns in the <a href="https://www.earth.com/news/hunger-alters-the-behavior-of-worms-and-perhaps-humans-too/" target="_blank" rel="noreferrer noopener">worms' activity</a>. Some were consistently active at the same time each night, while others showed sporadic activity, akin to "couch potatoes," with many variations in between. </p>



<p>What was particularly striking was the consistency of these patterns over time, suggesting ingrained biological rhythms. </p>



<p>"We were very surprised to see how reproducible the individual behavioral rhythms were," Tessmar-Raible remarks. "This shows us that even worms have tiny, rhythmic personalities, so to speak."</p>



<h2 class="wp-block-heading" id="h-genetic-rhythms-of-platynereis-dumerilii">Genetic rhythms of <em>Platynereis dumerilii</em></h2>



<p>The study went further to compare the genetic activity in the heads of both rhythmic and arrhythmic worms. Results showed that all worms maintained a robust internal clock, regardless of their activity pattern.</p>



<p>This finding suggests a diverse range of survival strategies among the worms. These strategies potentially offer evolutionary advantages in their fluctuating coastal environments.</p>



<h2 class="wp-block-heading" id="h-implications-for-conservation-and-medicine">Implications for conservation and medicine</h2>



<p>This diversity not only speaks to the resilience of <em>Platynereis dumerilii</em> but also has broader implications for how we understand the adaptability of all species to environmental changes. </p>



<p>It suggests that individual variability might be a key factor in the survival of species under the pressures of climate change and other anthropogenic impacts.</p>



<p>Furthermore, the study's findings resonate beyond marine biology into human medicine. The concept of individual biological rhythms plays a significant role in chronomedicine, which considers patients' natural rhythms in treatment plans. </p>



<p>Tessmar-Raible elaborates, "That's why such findings are also exciting for fields like chronomedicine," indicating that the variability seen in worms could mirror the human condition, impacting how treatments are tailored for different individuals.</p>



<h2 class="wp-block-heading" id="h-study-significance">Study significance</h2>



<p>This research not only broadens our understanding of marine life but also reinforces the significance of individual biological rhythms in both ecology and medicine. </p>



<p>As we continue to explore the intricate dance of life's timings, from the smallest worm to human beings, embracing these natural variations could be crucial to future biomedical advances and conservation efforts.</p>



<p>The full study was published in the journal <em><em><a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002572" target="_blank" rel="noreferrer noopener">PLoS Biology</a></em></em>.</p>



<p>-----</p>



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Even the simplest organisms, like worms, have unique personalities

Individual behaviors and rhythms in even the simplest marine creatures,...

<p>A study led by <a href="https://www.harvard.edu/">Harvard University</a> has provided a fresh perspective on evolutionary processes, particularly in how species intermingle and evolve. The experts have found compelling evidence that <a href="https://www.earth.com/news/hybridization-evolution-life/">hybridization</a> can lead to the formation of entirely new species, challenging traditional views of evolution as a neatly branching tree.</p>



<h2 class="wp-block-heading" id="h-evolution-of-heliconius-butterflies-nbsp">Evolution of Heliconius butterflies&nbsp;</h2>



<p>Revisiting a fascinating observation first made by naturalist Henry Walter Bates in 1861 and shared with Charles Darwin, the scientists examined the evolution of the Heliconius <a href="https://www.earth.com/news/heliconius-butterflies-have-a-surprising-aptitude-for-learning-and-remembering/">butterflies</a> of the Amazon.&nbsp;</p>



<p>Bates famously described these butterflies as a peek into nature's workshop for creating new species. Now, the researchers provided direct evidence of this phenomenon by documenting the evolution of a new butterfly species through hybridization.</p>



<h2 class="wp-block-heading" id="h-hybridization-and-new-species">Hybridization and new species</h2>



<p>The study focused on Heliconius butterflies, shedding new light on how a hybridization event from 180,000 years ago between <em>Heliconius melpomene</em> and an ancestor of today’s <em>Heliconius pardalinus</em> gave rise to a third species, <em>Heliconius elevatus</em>.&nbsp;</p>



<p>This new species is not just a blend of its progenitors but has distinct ecological and physiological traits, such as unique preferences for caterpillar host plants and specific adult characteristics like male sex pheromones, <a href="https://www.earth.com/news/butterflies-wing-colors/">wing color</a> patterns, and mate selection.</p>



<h2 class="wp-block-heading" id="h-hybridization-and-evolution">Hybridization and evolution</h2>



<p>“Historically hybridization was thought of as a bad thing that was not particularly important when it came to evolution,” said Neil Rosser, an associate in entomology at the <a href="https://mcz.harvard.edu/">Museum of Comparative Zoology</a> and a former postdoctoral fellow at Harvard. “But what genomic data have shown is that in fact hybridization among species is widespread.”</p>



<p>This discovery not only challenges the traditional concept that species are distinct, non-overlapping units, but also highlights the fluidity with which genetic material is exchanged in nature. “A lot of species are not intact units,” Rosser said. “They're quite leaky, and they’re exchanging genetic material.”</p>



<h2 class="wp-block-heading" id="h-evolution-of-completely-new-lineages-nbsp">Evolution of completely new lineages&nbsp;</h2>



<p>The research also raises important questions about how new species emerge from the intermingling of existing ones. “So the species that are evolving are constantly exchanging genes, and the consequence of this is that it can actually trigger the evolution of completely new lineages,” Rosser explained.</p>



<p>“Normally, species are thought to be reproductively isolated. They can’t produce hybrids that are reproductively fertile,” added co-author James Mallet, a professor of organismic and evolutionary biology at Harvard. Thus, although there is now evidence of hybridization between species, it was still difficult to confirm that this hybridization is, in some way, involved in speciation.</p>



<h2 class="wp-block-heading" id="h-fluid-nature-of-species-boundaries-nbsp">Fluid nature of species boundaries&nbsp;</h2>



<p>The implications of this study extend beyond academic circles. Understanding the fluid nature of species boundaries is crucial for conservation efforts, particularly in <a href="https://www.earth.com/news/climate-dictates-biodiversity-hotspots/">biodiversity hotspots</a> like the Amazon. It also has potential applications in studying disease vectors, such as mosquitoes that carry malaria, and their inter-species interactions.</p>



<p>This paradigm shift in understanding hybridization and evolution marks a significant advance, suggesting that the interplay of genetic material across species boundaries can play a pivotal role in the emergence of new species.</p>



<h2 class="wp-block-heading" id="h-more-about-heliconius-butterflies-nbsp">More about Heliconius butterflies&nbsp;</h2>



<p>Heliconius butterflies, also known as longwing butterflies, are a diverse and colorful group found primarily in tropical regions, particularly in Central and South America. They are notable for their striking patterns and vibrant colors, which serve as a form of defense through mimicry and warning signals. Heliconius butterflies exhibit a variety of interesting behaviors and adaptations:</p>



<h3 class="wp-block-heading" id="h-mullerian-mimicry">Müllerian mimicry</h3>



<p>Heliconius butterflies are famous for their participation in Müllerian mimicry, where multiple species share similar warning coloration to protect against predators, as the colors signal toxicity.</p>



<h3 class="wp-block-heading" id="h-diet-and-lifespan-of-heliconius-butterflies">Diet and lifespan of Heliconius butterflies </h3>



<p>Unlike most butterflies that sip nectar, Heliconius butterflies also feed on pollen, which is rich in proteins and extends their <a href="https://www.earth.com/news/warmer-autumns-reduce-the-life-expectancy-of-butterflies/">lifespan</a> significantly, often living several months rather than the usual weeks that most butterflies survive.</p>



<h3 class="wp-block-heading" id="h-reproduction-and-habitat">Reproduction and habitat</h3>



<p>They have unique reproductive behaviors, including the use of pheromones and lekking (males display in groups). They often return to the same spot each night, showing high site fidelity.</p>



<h3 class="wp-block-heading" id="h-conservation-status">Conservation status</h3>



<p>While some species are abundant and widespread, others are endangered and face threats from habitat destruction due to logging and agriculture.</p>



<h3 class="wp-block-heading" id="h-role-in-ecosystems">Role in ecosystems</h3>



<p>Heliconius butterflies are important pollinators in their ecosystems, helping to maintain the health and diversity of tropical forests.</p>



<p>The study is published in the journal <a href="http://dx.doi.org/10.1038/s41586-024-07263-w"><em>Nature</em></a><em>.</em></p>



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Butterflies show that new species can evolve from hybridization

A study led by Harvard University has provided a fresh...


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<p>Today’s <strong>Video of the Day</strong> from the <a href="https://www.esrf.fr/">European Synchrotron Radiation Facility</a> (ESRF) describes the details of a new study which reveals that dinosaurs died in the spring.</p>



<p>The researchers analyzed X-rays and carbon isotope records, which showed that fish died within 60 minutes after the Chicxulub meteoroid collided with the Earth.&nbsp;</p>



<p>For the analysis, the experts focused on the bones of the fish skeletons to examine seasonal growth rings.</p>



<p>“The retrieved growth rings not only captured the life histories of the fishes but also recorded the latest Cretaceous seasonality and thus the season in which the catastrophic extinction occurred,” explained study senior author Jeroen van der Lubbe.</p>



<p>“In all studied fishes, bone cell density and volumes can be traced over multiple years. These were on the rise but had not yet peaked during the year of death,” said study co-author Dennis Voeten.</p>



<p>In particular, the experts examined the diet of a paddlefish, which prefers to feed upon zooplankton. Throughout the year, the abundance of zooplankton fluctuates.&nbsp;</p>



<p>The study revealed that when the paddlefish died, zooplankton were approaching their summer climax.</p>



<p>“This temporary increase of ingested zooplankton enriched the skeleton of its predator with the heavier 13C carbon isotope relative to the lighter 12C carbon isotope,” explained Suzan Verdegaal-Warmerdam.</p>



<p>“The carbon isotope signal across the growth record of this unfortunate paddlefish confirms that the feeding season had not yet climaxed &#8211; death came in spring,” added study lead author Melanie During from Uppsala University.</p>



<p><em>Video Credit: ESA</em></p>



<p><em>&#8211;</em><em>&#8212;</em></p>



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


New evidence that dinosaurs died in the spring