How Frequent Are Antarctic Sudden Stratospheric Warmings in Present and Future Climate?. Issue 11 (5th June 2021)

• Record Type: Journal Article
• Authors: Jucker, M.; Reichler, T.; Waugh, D. W.
• Is Part Of: Geophysical research letters. Volume 48:Issue 11(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-05
• Subjects: atmospheric dynamics -- southern hemisphere -- stratosphere‐troposphere coupling -- sudden stratospheric warming; GLOBAL CHANGE: Climate variability -- Climate dynamics -- ATMOSPHERIC PROCESSES: Climate change and variability -- Stratosphere/troposphere interactions -- Stratospheric dynamics -- ATMOSPHERIC PROCESSES: Climatology -- General circulation -- NATURAL HAZARDS: Atmospheric -- Climate impact -- Disaster risk analysis and assessment; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2021GL093215
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Southern Hemisphere (SH) stratospheric sudden warmings (SSWs) result in smaller Antarctic ozone holes and are linked to extreme midlatitude weather on subseasonal to seasonal timescales. Therefore, it is of interest how often such events occur and whether we should expect more events in the future. Here, we use a pair of novel multimillennial simulations with a stratosphere‐resolving coupled ocean‐atmosphere climate model to show that the frequency of SSWs, such as observed 2002 and 2019, is about one in 22 years for 1990 conditions. In addition, we show that we should expect the frequency of SSWs, and that of more moderate vortex weakening events, to strongly decrease by the end of this century. Plain Language Summary: The stratosphere at 10–50 km height can influence surface weather for several months. In 2002 and 2019, the stratosphere warmed over Antarctica within a few days to weeks. This caused dry and hot summers in Australia and South America, and it reduced the size of the ozone hole. Since these warming events are rare, it is difficult to say how often they occur. We therefore use long computer simulations to answer that question. We find that without climate change, warming events occur about every 22 years, but with climate change, the warming events will happen only once every 300 years. From this, we believe that the quick succession of two events in 2002 and 2019 will remain special in history. Key Points: Antarctic sudden stratospheric warmings occur once every 22 years in present‐day (1990) climate conditions The warmings will become much rarer under future climate change, irrespective of their exact definition The future decrease in frequency is linked to a strengthening of the Antarctic polar vortex