Climate Change and Extreme Weather Events in the Moscow Agglomeration

Abstract: Based on monitoring data (surface observationnetwork and satellites) and on the results of climate simulations withthe COSMO-CLM and ENVI-MET models, the dynamics of the urban heat island(UHI) and wet/dry island and their 3D structure for the Moscowagglomeration are investigated. It is found that the Moscow UHI ismaintained by the anthropogenic heat influx to the urban atmosphere. Tosome extent, UHI is self-induced due to the feedback mechanism(providing approximately 10% of the effect) between temperature and thedownward flux of longwave radiation. The UHI creates a counterclockwisecirculation of airflows. The UHI and its circulation system arelogically considered a product of self-organization, when a meso-betascale circulation system is generated under the influence of multipleactions of small (meso-gamma scale) impacts. The UHI is accompanied bythe wet/dry island. The domed three-dimensional structure of the islandsis disturbed under steady strong winds and is transformed into the plumestructure. The interannual trend towards the UHI strengthening is noted.This determines the effect of the warming acceleration related to theglobal warming and an increase in the discomfort effects in the Moscowurban system. The intense heat waves (1972, 2002, and 2010) which causedcatastrophic droughts and wildfires in the European part of Russia arethe major factor of vulnerability of the Moscow economy and population.In addition, the influence of the anomalies is amplified by the urbanenvironment. © 2020, Allerton Press, Inc.