Stratospheric temperature features over Saudi Arabia and their relationship to Atlantic SSTs and surface temperatures in winter

Abstract

Stratospheric temperature is an important climatic factor regionally and globally. This paper investigates temperature trends in the lower stratosphere at 50 hPa (T50), the mid-stratosphere at 30 hPa (T30), and the upper stratosphere at 10 hPa (T10), as well as their impacts on Atlantic Ocean sea surface temperature (SST) and Saudi Arabian surface air temperature (SAT) during the entire winter seasons of 1979-2019. The results show significant cooling for the T50 linear trend, progressive cooling for the T30 linear trend, and cooling for the T10 linear trend during the study period over Saudi Arabia. The results also indicate a significant nonlinear cooling trend for stratospheric temperature at T50 and T30, while a weak cooling at T10 is observed. Abrupt climatic changes towards warmth exist at all three levels of stratospheric temperature, which occur in 1992 for T50 and T30 and in 1983 for T10. These abrupt climate changes may be related to volcanic eruptions. Our results also indicate that a strong negative relationship exists between T50 and the SST of the tropical South Atlantic (TSA) and the Atlantic Multi-Decadal Oscillation (AMO), while T30 indicates a statistically negative relationship with the AMO. The lead-lag cross-correlation suggests that the SST of the Atlantic Ocean (tropical North Atlantic [TNA], TSA, and AMO) are linked to stratospheric temperatures at three lead winters. As a result of the teleconnection between SAT and stratospheric temperature over Saudi Arabia, the coupling of these two features occurs in winter, especially in the lower to mid-stratosphere layers.