The Arctic Temperature Response to Global and Regional Anthropogenic Sulfate Aerosols

• Published in: Frontiers in Environmental Science
• Main Authors: Asutosh, Acharya, Fadnavis, Suvarna, Nuncio, M., Müller, Rolf, Tripathy, Sarat C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media 2021
• Subjects: info:eu-repo/classification/ddc/333.7; Arctic
• Online Access: https://juser.fz-juelich.de/record/902560; https://juser.fz-juelich.de/search?p=id:%22FZJ-2021-04359%22

The mechanisms behind Arctic warming and associated climate changes are difficult todiscern. Also, the complex local processes and feedbacks like aerosol-cloud-climateinteractions are yet to be quantified. Here, using the Community Earth System Model(CAM5) experiments, with emission enhancement of anthropogenic sulfate 1) five-foldglobally, 2) ten-times over Asia, and 3) ten-times over Europe we show that regionalemissions of sulfate aerosols alter seasonal warming over the Arctic, i.e., colder summerand warmer winter. European emissions play a dominant role in cooling during the summerseason (0.7 K), while Asian emissions dominate the warming during the winter season(maximum ∼0.6 K) in the Arctic surface. The cooling/warming is associated with a negative/positive cloud radiative forcing. During the summer season increase in low–mid levelclouds, induced by sulfate emissions, favours the solar dimming effect that reduces thedownwelling radiation to the surface and thus leads to surface cooling. Warmer winters areassociated with enhanced high-level clouds that induce a positive radiative forcing at thetop of the atmosphere. This study points to the importance of international strategies beingimplemented to control sulfate emissions to combat air pollution. Such strategies will alsoaffect the Arctic cooling/warming associated with a cloud radiative forcing caused bysulfate emission change.