Ice

In the Arctic, the freedom to travel, hunt and make day-to-day decisions is profoundly tied to cold and frozen conditions for much of the year. These conditions are rapidly changing as the Arctic warms. The Arctic is now seeing more rainfall when historically it would be snowing. Sea ice that once protected coastlines from erosion during fall storms is forming later. And thinner river and lake ice is making travel by snowmobile increasingly life-threatening. Ship traffic in the Arctic is also increasing, bringing new risks to fragile ecosystems, and the Greenland ice sheet is continuing to send freshwater and ice into the ocean, raising global sea level In the annual Arctic Report Card, released Dec. 13, 2022, we brought together 144 other Arctic scientists from 11 countries to examine the current state of the Arctic system. Some of the Arctic headlines of 2022 discussed in the Arctic Report Card. NOAA Climate.gov...

Clouds form when water vapor – an invisible gas in the atmosphere – sticks to tiny floating particles, such as dust, and turns into liquid water droplets or ice crystals. In a newly published study, we show that microplastic particles can have the same effects, producing ice crystals at temperatures 5 to 10 degrees Celsius (9 to 18 degrees Fahrenheit) warmer than droplets without microplastics. This suggests that microplastics in the air may affect weather and climate by producing clouds in conditions where they would not form otherwise. We are atmospheric chemists who study how different types of particles form ice when they come into contact with liquid water. This process, which occurs constantly in the atmosphere, is called nucleation. Clouds in the atmosphere can be made up of liquid water droplets, ice particles or a mixture of the two. In clouds in the mid- to upper atmosphere where temperatures are between 32 and minus 36 F (0 to minus 38 C), ice crystals...