A254-08
Opposite responses of the dry and moist eddy heat transport into the Arctic in the PAMIP experiments

Thursday, 17 December 2020: 07:28
Virtual
Alexandre Audette1, Robert Andrew Fajber1, Paul J Kushner1, Yutian Wu2, Yannick Peings3, Gudrun Magnusdottir4, Rosemary Eade5, Michael Sigmond6 and Lantao Sun7, (1)University of Toronto, Physics, Toronto, ON, Canada, (2)Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, United States, (3)University California Irvine, Irvine, CA, United States, (4)University of California Irvine, Earth System Science, Irvine, CA, United States, (5)Met Office Hadley center for Climate Change, Exeter, EX1, United Kingdom, (6)Canadian Centre for Climate Modelling and Analysis, Victoria, BC, Canada, (7)Colorado State University, Department of Atmospheric Science, Fort Collins, CO, United States
Abstract:
Given uncertainty in the processes involved in polar amplification, elucidating the role of poleward heat and moisture transport is crucial.
The Polar Amplification Model Intercomparison Project (PAMIP) permits robust separation of the effects of sea ice loss from sea surface warming under climate change. A moist isentropic circulation framework accounts for moisture transport, condensation, and eddy transport, while connecting the midlatitudes and the Arctic. It is found that sea ice loss reduces poleward heat transport (PHT) by warming the returning branch of the moist isentropic circulation at high latitudes, while warming of the ocean surface strengthens the overturning circulation, increasing the total PHT. Inter-model spread of PHT into the Arctic reflects the tug-of-war between sea-ice and surface-warming effects.