Influence of projected Arctic sea ice loss on polar stratospheric ozone and circulation in spring

Abstract. The impact of projected Arctic sea ice loss on the stratosphere is investigated using the Whole Atmosphere Community Climate Model (WACCM), a state-of-the-art coupled chemistry climate model. Two 91-year simulations are conducted: one with a repeating seasonal cycle of Arctic sea ice for t...

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Bibliographic Details
Main Authors: Lantao Sun, Clara Deser, Lorenzo Polvani, Robert Tomas
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.643.6529
http://www.cgd.ucar.edu/staff/cdeser/docs/submitted.sun.sea_ice_stratosphere.jul14.pdf
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Summary:Abstract. The impact of projected Arctic sea ice loss on the stratosphere is investigated using the Whole Atmosphere Community Climate Model (WACCM), a state-of-the-art coupled chemistry climate model. Two 91-year simulations are conducted: one with a repeating seasonal cycle of Arctic sea ice for the late twentieth century, taken from the fully-coupled WACCM historical run; the other with Arctic sea ice for the late twenty-first century, obtained from the fully-coupled WACCM RCP8.5 run. In response to Arctic sea ice loss, polar cap stratospheric ozone decreases by 13 DU (34 DU at the North Pole) in spring, confirming the results of Scinocca et al. (2009). The ozone loss is dynamically initiated in March by a suppression of upward-propagating planetary waves, possibly related to the destructive interference between the forced wave number 1 and its climatology. The diminished upward wave propagation, in turn, weakens the Brewer-Dobson circulation at high-latitudes, strengthens the polar vortex, and cools the polar stratosphere. The ozone reduction persists until the polar vortex breaks down in late spring.