An Estimate of the Relative Contributions of Sea Surface Temperature Variations in Various Regions to Stratospheric Change

Abstract

This study investigates the effects of global and regional sea surface temperature (SST) warming from the Industrial Revolution to the present on the stratosphere using a climate model, and estimates the relative contributions of SST warming in different regions. The observed global SST warming is found to cause colder and stronger stratospheric zonal circulations in the high latitudes of both hemispheres, and a colder lower stratosphere in the tropics and ozone depletion. This occurs because the warming in the tropical Atlantic and in the north Indian Ocean and North Pacific strongly cool the stratosphere in the southern and northern high latitudes, respectively. The cooling in the lower stratosphere at lower and midlatitudes is mainly caused by SST warming in the tropical Pacific and north Indian Ocean. The changes in stratospheric temperature are related to changes in circulation and ozone. In addition, we investigate the effects on the stratosphere of ideal 1-K uniform warming of SST in different oceans and compare these effects with those caused by the realistic SST warming. The observed global SST warming and 1-K uniform global SST warming have opposite effects on the high-latitude stratosphere in both hemispheres: 1-K uniform global SST warming results in warmer and weaker stratospheric zonal circulations and a corresponding increase in ozone. This is because the 1-K uniform increase in SST in the tropical Pacific causes extremely strong warming and weakening stratospheric zonal circulations. The contribution of a 1-K uniform increase of SST in the tropical Pacific to stratospheric temperature, circulation, and ozone anomalies overwhelms that of a 1-K uniform increase of SST in other regions.

The Remarkably Strong Arctic Stratospheric Polar Vortex of Winter 2020: Links to Record-Breaking Arctic Oscillation and Ozone Loss

“…to seasonal variability in the Arctic polar vortex. Some studies tied the previous strong and cold springtime polar vortices of 1997 and 2011 to positive SST anomalies in the north central Pacific (Hurwitz et al, 2011; more generally, SSTs in this region have been shown to modulate tropospheric planetary wave activity and the strength of the vortex manuscript submitted to JGR: Atmospheres (e.g., Hu et al, 2018;Xie et al, 2020). Positive SST anomalies in the Indian Ocean have also been shown to encourage a strengthened Arctic polar vortex and positive NAM in the troposphere (Hoerling & Kumar, 2002;Hoerling et al, 2004;Li et al, 2010;Fletcher & Kushner, 2011), particularly in isolation from impacts by the El Niño-Southern Oscillation (ENSO) (Fletcher & Cassou, 2015).…”

The Remarkably Strong Arctic Stratospheric Polar Vortex of Winter 2020: Links to Record‐Breaking Arctic Oscillation and Ozone Loss

“…Detailed modeling and attribution studies will be necessary to determine whether such processes played a role in the development of the strong polar vortex and/or the AO event over simple internal variability.For example, sea surface temperatures (SSTs) in various regions have been linked to seasonal variability in the Arctic polar vortex. Some studies tied the previous strong and cold springtime polar vortices of 1997 and 2011 to positive SST anomalies in the north central Pacific (Hurwitz et al, 2011, 2012); more generally, SSTs in this region have been shown to modulate tropospheric planetary wave activity and the strength of the vortex (e.g., Hu et al, 2018; Xie et al, 2020). Positive SST anomalies in the Indian Ocean have also been shown to encourage a strengthened Arctic polar vortex and positive NAM in the troposphere (Fletcher & Kushner, 2011; Hoerling & Kumar, 2002; Hoerling et al, 2004; Li et al, 2010), particularly in isolation from impacts by the El Niño–Southern Oscillation (ENSO) (Fletcher & Cassou, 2015).…”

“…the strength of the vortex (e.g., Hu et al, 2018;Xie et al, 2020). Positive SST anomalies in the Indian Ocean have also been shown to encourage a strengthened Arctic polar vortex and positive NAM in the troposphere (Fletcher & Kushner, 2011;Hoerling & Kumar, 2002;Hoerling et al, 2004;Li et al, 2010), particularly in isolation from impacts by the El Niño-Southern Oscillation (ENSO) (Fletcher & Cassou, 2015).…”

Weakening of Antarctic Stratospheric Planetary Wave Activities in Early Austral Spring Since the Early 2000s: A Response to Sea Surface Temperature Trends

“…where Previous studies have indicated that SST impact on the stratosphere shows a spatial dependence (e.g. Xie et al, 2020). To find out a robust relationship between the trend of SST in a specific region and the trend of stratospheric wave activities, we divide summarized and listed in Table 1 and Table 2.…”

“…In this section, we further explore factors that lead to the weakening of tropospheric wave sources and stratospheric wave activities since the early 2000s in early austral spring. Numerous studies reported that the variations in sea surface temperature can affect stratospheric climate (e.g., Li, 2009;Hurwitz et al, 2011;Lin et al, 2012;Hu et al, 2014;Hu et al, 2018;Tian et al, 2018;Xie et al, 2020). Hu & Fu (2009) also attributed the strengthened stratospheric wave activities in the southern hemisphere to SST trend from the early 1980s to the early 2000s.…”