Variation of Polar CO2 and O3 During Sudden Stratospheric Warming

The global distributions of chemical species retrieved from the Atmospheric Infrared Sounder (AIRS) offer a unique opportunity to study the large-scale dynamics in the polar region. In this study, we investigate the influence of sudden stratospheric warming (SSW) on AIRS CO2 and O3 in the polar region in March 2005. Results from observation demonstrate that the polar mid-tropospheric CO2 (O3) will increase (decrease) during the stratospheric major warming. To better investigate the influence of SSW on tracers, we also calculate the Eliassen-Palm (EP) flux and divergence. The EP-flux divergence is negative before the SSW, as a result the westerly wind in the stratosphere decreases. During the SSW, polar zonal mean wind switches to easterly and the temperature increases by about 4 K. The polar vortex is much weaker during the SSW. Mid-latitude CO2 (O3) is transported to the high latitudes and lead to the increase (decrease) of mid-tropospheric CO2 (O3) concentrations in the polar region, which is seen in the AIRS CO2 and O3 retrievals.