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    River turbulence can push toxic pollutants into the air

    Toxic pollutants from a Southern California river are infiltrating the air.

    Polluted water surging along a turbulent section of the Tijuana River in San Diego can release toxic gases, including hydrogen sulfide, into the air, researchers report in the Aug. 28 Science. In a nearby neighborhood, hydrogen sulfide — produced from sewage breakdown and known for its rotten egg smell — peaked at levels thousands of times the typical urban amounts.

    “As far as we can tell, this is one of, if not the first time, that we’ve seen a full-on air pollution crisis caused by a river, especially one so close to the community,” says Benjamin Rico, an atmospheric chemist at the University of California, San Diego. More

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    A glacier burst, flooding Juneau. Again. This one broke records

    A glacial outburst has sent floodwaters rushing through the town of Juneau, Alaska, forcing residents to evacuate parts of the state capital. The unusual event, called a glacial lake outburst flood, or GLOF, happened as water spilled out of an ice-dammed lake and gushed downstream through melted tunnels in the underside of a large glacier.

    The people of Juneau have experienced at least one such flood every summer for the last 15 years.

    “It’s a story about glacier change,” says Jason Amundson, a glaciologist at the University of Alaska Southeast in Juneau, who is monitoring the event. The warming climate has caused glaciers here to shrink and separate from one another. That’s left an empty valley along the edge of Mendenhall Glacier, which now fills with rain and meltwater each summer. At some point, the water collects deep enough that its pressure forces an opening under the edge of the glacier — allowing it to escape. More

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    See how aerosols loft through Earth’s sky

    The sky abounds with aerosols, tiny particles with large sway over Earth’s temperature. A new NASA visualization reveals how these airborne particles swirl through the atmosphere.

    The agency’s Goddard Earth Observing System tracks major aerosol types — sulfates, black carbon, dust and sea salt. It combines satellite and ground-based observations with advanced computer simulations to show how aerosols can affect air quality and visibility far from their sources. See where they loft in this visualization spanning August 1 to September 14, 2024. More

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    Skyborne specks of life may influence rainfall patterns

    Sprinklings of life appear key to the recipe for rain.

    Lofted flecks of organic material like bacteria, pollen and fungal spores play a profound role in regulating rainfall patterns, a new study suggests. These bioparticles can make up a major portion of all the particles that can seed rain in the sky, and their levels fluctuate in a daily cycle, researchers report May 5 in npj Climate and Atmospheric Science.

    The study is the first to clearly show that the movements of bioparticles drive daily fluctuations of rainmaking particles more broadly. “This really has not been included in any [weather] models before,” says atmospheric scientist Athanasios Nenes of EPFL, the Swiss Federal Institute of Technology in Lausanne. “It’s something we need to start thinking about.” More

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    Fires in the Amazon forest may melt sea ice in Antarctica

    Soot from forest fires in the Amazon might play a role in the melting of faraway ice in Antarctica.

    For decades, scientists have known that black carbon from burning fossil fuels or forests accelerates ice melt in different parts of the world. According to remote sensing researcher Sudip Chakraborty, the slash-and-burn practices encouraged by Brazil’s former president Jair Bolsonaro, who held office from 2019 to 2023, inspired his team to investigate whether black carbon from the Amazon affected ice melt in Antarctica. More

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    A podcast challenges us to reassess our relationship with wildfires

    United by FireDenver Museum of Nature & ScienceAvailable wherever you get your podcasts

    For hundreds of millions of years, wildfires were directed solely by the weather, vegetation and terrain. But in the last century in the United States, people have sought to suppress even those beneficial fires that would otherwise clear out dead vegetation, which can fuel wildfires, and stimulate new growth. Now, catastrophic megafires erupt each year, and in some places, climate change has extended the fire season. Clearly something has to give — our society must change its relationship with fire. More

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    Fire-prone neighborhoods on the fringes of nature are rapidly expanding

    People are flocking to nature’s doorstep, and into wildfire territory.

    Homes constructed where human development meets undeveloped wildland are particularly vulnerable to wildfires and other natural hazards (SN: 11/9/23). Nonetheless, people are moving into the wildland-urban interface, or WUI, and rapidly expanding it. From 2000 to 2020, the global footprint of the WUI grew by about 35 percent, reaching a total area that’s roughly the size of Mexico, researchers report November 8 in Science Advances. More

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    An idea to save Mexico’s oyamel forests could help monarch butterflies too

    An experiment to grow new forests in central Mexico offers hope that the crucial winter habitat for millions of migrating monarch butterflies could survive into the next century.

    When scientists decided to plant hundreds of baby oyamel fir trees (Abies religiosa) about 100 kilometers from their native habitat, they weren’t sure how many trees would survive. Today, most of the saplings are flourishing, researchers report September 17 in Frontiers in Forests and Global Change. Even at an altitude of 3,800 meters, high above where the trees usually grow, almost 70 percent of the saplings survived at least three years. More