Abstract
Previous studies showed significant stratospheric warming at the Southern-Hemisphere (SH) high latitudes in September and October over 1979–2006. The warming trend center was located over the Southern Ocean poleward of the Western Pacific in September, with a maximum trend of about 2.8 K/decade. The warming trends in October showed a dipole pattern, with the warming center over the Ross and Amundsen Sea, and the maximum warming trend is about 2.6 K/decade. In the present study, we revisit the problem of the SH stratospheric warming in the recent decade. It is found that the SH high-latitude stratosphere continued warming in September and October over 2007–2017, but with very different spatial patterns. Multiple linear regression demonstrates that ozone increases play an important role in the SH high-latitude stratospheric warming in September and November, while the changes in the Brewer-Dobson circulation contributes little to the warming. This is different from the situation over 1979–2006 when the SH high-latitude stratospheric warming was mainly caused by the strengthening of the Brewer-Dobson circulation and the eastward shift of the warming center. Simulations forced with observed ozone changes over 2007–2017 shows warming trends, suggesting that the observed warming trends over 2007–2017 are at least partly due to ozone recovery. The warming trends due to ozone recovery have important implications for stratospheric, tropospheric and surface climates on SH.
Highlights
It is well known that the ozone layer experienced depletion in the last quarter of the twentieth century
The warming trends in upper panels are almost the same as that in Hu and Fu (2009) they are from different Microwave Sounding Unit (MSU)/ Advanced Microwave Sounding Units (AMSU) datasets
Significant warming trends in October are located over the Amundsen Sea and Ross Sea (Fig. 1b), with significant cooling trends over the sector of the Indian Ocean
Summary
It is well known that the ozone layer experienced depletion in the last quarter of the twentieth century. In contrast to the cooling trend, Johanson and Fu (2007) and Hu and Fu (2009) found warming trends over a large portion of the Southern-Hemisphere (SH) high-latitude stratosphere in September and October, and the warming and cooling trends demonstrate a wavenumber 1 pattern. Their results, derived from satellite Microwave Sounding Unit (MSU) observations, show the largest warming of 7–8 °C in the September and October over the period of 1979–2006. Little attention was paid to the warming trends because all these studies had concentrated on ozone-induced stratospheric cooling
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
