Role of spring soil moisture in the formation of large-scale droughts in the East European Plain in 2002 and 2010

Abstract

Using COSMO-CLM (a nonhydrostatic atmospheric model designed for climate experiments), we simulate the summer anomalies in the meteorological regime of 2010 and 2002 over the central part of the East European Plain. The module of soil moisture treatment is shown to demonstrate reliable results and the radiation module of the model needs to incorporate the optical properties of haze generated by the smoke of forest and peat fires. It is shown that the soil moisture content formed in the spring can (due to its inertial behavior and by changing the heat balance structure) participate in the formation of temperature and humidity anomalies over 3–4 months. The extremeness of the thermal regime in the summer of 2010 in the central part of the East European Plain is due to (all other conditions being equal) the specific values of soil moisture content w 0 = 0.6–0.65. The revealed fine dependence of the phenomenon on the spring state of soil moisture makes it important to improve the monitoring of soil moisture as a key factor in the dynamics of extreme weather anomalies.