Aerosols indirectly warm the Arctic

• Main Authors: Mauritsen, Thorsten, Sedlar, Joseph, Tjernström, Michael, Leck, Caroline, Martin, M., Shupe, Matthew, Sjogren, S., Sierau, Berko, Persson, P.O.G., Brooks, Ian M., Swietlicki, Erik
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus 2011
• Subjects: Arctic; Arctic Ocean
• Online Access: https://hdl.handle.net/20.500.11850/28541; https://doi.org/10.3929/ethz-b-000028541

On average, airborne aerosol particles cool the Earth’s surface directly by absorbingand scattering sunlight and indirectly by influencing cloud reflectivity, life time, thicknessor extent. Here we show that over the central Arctic Ocean, where there is frequentlya lack of aerosol particles upon which clouds may form, a small increase in aerosol5loading may enhance cloudiness thereby likely causing a climatologically significantwarming at the ice-covered Arctic surface. Under these low concentration conditionscloud droplets grow to drizzle sizes and fall, even in the absence of collisions andcoalescence, thereby diminishing cloud water. Evidence from a case study suggeststhat interactions between aerosol, clouds and precipitation could be responsible for10attaining the observed low aerosol concentrations. ISSN:1680-7375 ISSN:1680-7367