On the Contribution of Prof. Lev Gutman to Nonhydrostatic Atmospheric Modeling for Weather Prediction in the USSR-Russia

Rossby’s approach in late ‘30s opened a way to isolate the waves, having the wavelength of a few thousand kilometers (responsible for transferring large-scale mid-latitude weather systems such as cyclones, anticyclones, and atmospheric fronts) from other kinds of atmospheric motions. This approach implied that the horizontal pressure-gradient force and Coriolis force are close to balance in the large-scale atmospheric motions, which is true with an accuracy of 80-90 per cent for the free atmosphere in the extratropics. In the USSR, an important step towards further progress in the atmospheric modeling was made by a team of scientists led by Dr. Gury Marchuk at the Computer Center of the Siberian Branch of the Soviet Academy of Sciences in Novosibirsk, where Prof. Lev Gutman was the Head of the Laboratory for Meso-Scale Meteorological Processes. A new methodology for solving the system of primitive equations of oceanic and atmospheric dynamics using a split-method approach developed by Marchuk did not allow the representation of meso-meteorological processes, such as local winds, urban heat islands, atmospheric fronts, thunderstorms or tornadoes. Research activities under Prof. Lev Gutman contributed to the solution of the problems in this part of the atmospheric science. Gutman’s work tackled the nonlinear structure of breezes and mountain valley winds, temperature distribution in the surface boundary layer, which included the air, snow and soil. His theoretical work, thus, contributed to the development of an operational method for the computation of soil temperature using air temperature data, which was an important practical application problem. Prof. Gutman’s work on the mechanism of the atmospheric vertical instability led to significant results in the theory of cumuli clouds and tornadoes, spatial relief flowlines, and katabatic winds. In early 1970s, Prof. Gutman and his team contributed to solving equations in the theory of turbulence, which, in turn, developed into a theory of meso-meteorological boundary layer. By this time, numerical simulation methods were used. These research efforts furthered the high resolution weather prediction atmospheric modeling and finding solutions in local weather forecasting. It was also an important step in incorporating the parameterizations of mesoscale processes in short-term weather forecasting in the USSR. During the last couple of decades this manifested by active participation of Russia’s research team in joint international coordinated efforts on mesoscale weather prediction modeling with different modern from the NCAR/NCEP MM5 to COSMO consortium modeling systems.