Prominent mode of summer surface air temperature variability and associated circulation anomalies over the Arabian Peninsula

Raju Attada,Ravi Kumar Kunchala,Ramesh Kumar Yadav,Ibrahim Hoteit,Omar Knio,Hari Prasad Dasari

doi:10.1002/asl.860

Abstract

This study investigates the dominant modes of surface air temperature (SAT) variability and associated circulation changes over the Arabian Peninsula (AP) during summer for the period 1979–2016 based on an empirical orthogonal function (EOF) analysis. The analysis results reveal that the first leading EOF mode is related to the weakening of the subtropical westerly jet stream, which may impact the AP temperature variability through the mid‐latitude Rossby wave trains (successive troughs and ridges). This can be explained by the high correlation of the AP summer temperatures with the quasi‐stationary mid‐latitude/extratropical Eurasian Rossby wave train type patterns, which influences the air temperature variability by modulating the Asian Jets. Furthermore, the high AP SAT variability is also closely associated with strong middle to lower tropospheric descent (subsidence) anomalies, which cause warm temperature anomalies over this region.

Highlights

Air temperature is an important climatic parameter that affects the world socio-economy and is commonly employed to assess regional climate variations and climate change (e.g., Alkolibi, 2002; Walther et al, 2002)
The results indicate that the principal components (PCs) of the first empirical orthogonal function (EOF) (Figure 2a) time series and the 2-m air temperature (2mT) anomalies are highly correlated, with 99.9% significance level, over the Arabian Peninsula (AP), East Asia, central Asia, the Middle East, and North Africa (MENA), the eastern Mediterranean (EM), and eastern Europe
The net solar radiation is negatively correlated with the PC of the first EOF of 2mT over the AP, eastern Africa, and western European regions (Figure 3c) during summer as a result of high surface temperatures over the desert regions, which lead to net loss of radiation over the AP

Summary

Introduction

Air temperature is an important climatic parameter that affects the world socio-economy and is commonly employed to assess regional climate variations and climate change (e.g., Alkolibi, 2002; Walther et al, 2002). Very few efforts have been, investigated the dynamical factors behind the variations of the AP temperatures, despite several studies suggesting that the AP SATs are controlled by various large-scale circulation patterns (Hasanean and Almazroui, 2016; Attada et al, 2018b). Recent studies suggested that the mid-latitude/extratropical Eurasian Rossby wave is an important factor in describing the regional temperature variability during summer (e.g., Yadav, 2017).

Results

Conclusion