Regional Climate Model Simulation of Present-day Regional Climate over the European Part of Russia with RegCM3

S. O. Krichak

A regional climate model RegCM3 with a horizontal spacing of 60 km and18 levels along its vertical coordinate is applied for simulation of the climate of the European part of Russia. Continuous integration of the model is performed for the period from January 1982 to December 1994. The simulation results are discussed in comparison with the observations available and results of earlier similar studies. The model successfully describes the climate of the region. The model successfully reproduces interannual variations of temperature and precipitation over the region as well as their standard deviations. Space distribution of summer precipitation is also reasonably simulated. A positive bias in the determination of the near-surface air-temperatures characterizes the modeling results over the northern part of the area during the cool season. Also, a positive air-temperature bias characterizes the results over the southern part of the model domain during summer. Precipitation intensity is underestimated during the cool season and overestimated (20–30%) during summer. A positive bias also characterizes the simulated air temperatures during summer over the southern part of the domain. Also, a positive bias characterizes the simulated temperatures during cool season, especially in the northern part of the domain. The systematic defects detected may result from an insufficiently accurate description of the radiative cooling in the model because of an insufficient space resolution and the size of the domain. Overestimated near-surface air temperatures in summer over the southern part of the domain may be caused by insufficient soil moisture in the model and defects in description of the energy balance.