A Cases Study Of Mongolian Cyclogenesis During The July 2018 Blocking Events

Olga Yu Antokhina,Vladimir I Mordvinov,Inna V Latysheva

doi:10.24057/2071-9388-2019-14

Abstract

Mongolia and Transbaikalia (M-TB) have experienced severe drought over the past 20 years due to the increased frequency of anticyclogenesis. However, in the summer of 2018, as a result of the formation of a series of cyclones over Mongolia and their move to the Transbaikalia, abnormally high precipitation was observed in the M-TB region. The dynamics of long Rossby waves and atmospheric blocking in the middle and upper troposphere were investigated to identify the causes of cyclogenesis over Mongolia. It was revealed that a sequence of events predefined the extreme precipitation in M-TB in the 2018 summer – the intensification of heat flux over the North Atlantic while maintaining cyclonic vorticity over Central Europe, the development of blocking ridges in the Urals and the Russian Far East, and an upper-level trough oriented to the eastern regions Mongolia. For a long time, the persistent advection of cold air in the rear part of the upper-level trough, as well as increased heat advection during the activation of the East Asian summer monsoon, caused meridional oriented upper-level front strengthening over the eastern regions of Mongolia and extreme precipitation.

Highlights

Mongolia and Transbaikalia (M-TB) have experienced severe drought in recent decades due to a decrease in precipitation and an increase in air temperature in summertime (Davi et al 2006, 2013; Berezhnykh et al 2012; Erdenebat et al 2015; Obyazov et al 2015; Shubert et al 2014; Hessl et al 2018)
The precipitation and streamlines at 850 hPa maps allow us to compare the dynamics of synoptic disturbances in the lower troposphere and the rainfall associated with them, maps in Fig. A1 on the right – to analyze the large-scale structure of the pressure fields in the period of formation and moving of the Mongolian cyclogenesis (MC’s)
The paper studied the development of the Mongolian cyclogenesis (MC’s) in July 2018

Summary

Introduction

Mongolia and Transbaikalia (M-TB) have experienced severe drought in recent decades due to a decrease in precipitation and an increase in air temperature in summertime (Davi et al 2006, 2013; Berezhnykh et al 2012; Erdenebat et al 2015; Obyazov et al 2015; Shubert et al 2014; Hessl et al 2018). A recent decade-long drought that exceeded the variability in the instrumental record (Hessl et al 2018) caused economic, social, and environmental change (Karthe et al 2014, Kasimov et al 2017). The changes have affected the discharge of the Selenga River. Since the Selenga River is the main tributary of Lake Baikal (Berezhnykh et al 2012), a decrease in its discharge has caused a reduction of the inflow into the lake, especially in 2014–2015 (Bychkov and Nikitin 2015).

Methods

Results

Conclusion