Modern Climate-Related Changes in Heat Supply, Moistening, and Productivity of the Agrosphere in Russia
O. D. Sirotenko, G. V. Gruza, E. Ya. Rankova, E. V. Abashina, and V. N. Pavlova
Climate changes observed in recent decades are analyzed, and the respective climate-related tendencies of changes in heat supply, moistening, and productivity of the agrosphere that determine the natural resourse of potential Russia are determined. The grain crop yield trends are used additionally as climate change indicators. It is shown that climate changes observed in the last 30 years promote the increase in potential agriculture productivity in most of the Russian Federation, where not less than 85% of agricultural products are produced. At the same time, the increase in climate aridity is observed in several regions of Siberia and Chernozem Center, which results in a reduced productivity of agriculture.
Long-Term Changes of Water Balance Components in the Basins of Rivers Fed by Snow and Ice
V. G. Konovalov
The variability of the main components of the annual water balance (precipitation, evaporation, glacial alimentation, and dynamic water reserves in the basin) for 1935–1990 is, for the first time, determined for the area where the Zeravshan runoff is formed, higher than hydrological post Dupuli is located. Long-term data on the annual Zeravshan River runoff from an area of 10 200 km2 were derived from the measurements at Dupuli hydrological post. The other water balance components were determined with the help of computation methods. Comparison of the measured and calculated volumes of the annual runoff demonstrated that a relative difference between them is systematic, and as a whole for a computation period it is in the interval from –0.31 to –4.78%. The annual balance of accumulation and thawing of solid precipitation on glaciers and in the extraglacial area is also determined in the Zeravshan River basin. A new method for computing and mapping spatial variability of the maximum snowline altitude is developed.
Structural Classification of Dynamometamorphic Transformations of First-Year Sea Ice
K. P. Tyshko
This paper considers the main features of the structure of dynamometamorphic transformations of first-year ice. The structural classification of these transformations is proposed based on laboratory and natural investigations. It is a logical development of the existing structural classification of first-year ice forming in the Arctic seas without the influence of external forcing on the ice cover.
Influence of Shoreline Configuration on Characteristics of Coastal Currents
V. B. Titov
Three basic types of shoreline are singled out: convex, concave, and even. Statistical characteristics of the currents near each type of shoreline were subjected to comparative analysis. Characteristic features of the current regime for each type of shoreline configuration were determined.
Determining Cyclone Trajectories and Velocities Leading to Extreme Sea Level Rises in the Gulf of Finland
A. S. Averkiev and K. A. Klevanny
Results of numerical modeling of water level rises (floods) in St. Petersburg are given. Simulations were carried out with the CARDINAL numerical model. Roles of different mechanisms in flooding are estimated. Numerical experiments were done for an idealized round cyclone with parameters of the cyclone of January 9, 2005, when the water level rose to 239 cm in St. Petersburg (central pressure of the cyclone was 965–970 hPa and wind speed reached 30 m/s). Sea level rises are obtained for different paths of such a cyclone over the Baltic Sea and for different velocities of its propagation. The most dangerous paths and velocities are determined.
Preliminary Results of Modeling Studies on Washout of Stable and Radioactive Analogs of 90Sr and 137Cs from Snow-Covered Areas
S. M. Vakulovskii, M. A. Novitskii, N. F. Mazurin, E. G. Tertyshnik, and L. M. Khachaturova
Experimental field and laboratory studies on washout of radionuclides from the snow cover during snow melting were carried out in the winter of 2005/06. In the field studies, a specially equipped runoff site was used. In the laboratory conditions, the experiments were conducted using prepared soil monoliths. In the winter of 2006, 25 g/m2 of water-free cesium chloride (CsCl) and 25 g/m3 of strontium chloride (SrCl2) were put onto the snow cover surface of the runoff site. The snow surface of the soil monolith was coated with a 137Cs-bearing solution, then with SrCl2. Under experimental conditions, practically no surface runoff from the runoff site was recorded. The experiments with the soil monoliths demonstrated that the coefficient of the liquid washout of 137Cs normalized to the runoff layer was within 0.9 * 10–6–1.2 * 10–4 mm–1, and that of 90Sr normalized to the runoff layer was within 2 * 10–6–1.6 * 10–4 mm–1.
Some Diabatic Indices of the Monsoon Circulation in the Indian Region
A. I. Degtyarev
The influence of outgoing longwave radiation anomalies on precipitation rates is studied based on the NCEP/NCAR reanalysis during the period of the summer monsoon circulation in the Indian region. The outgoing longwave radiation data are analyzed for 1987 (dry monsoon) and 1988 (wet monsoon) separately for the Arabian Sea, India, and the Bay of Bengal. It is shown that negative outgoing longwave radiation anomalies correspond to a wet Indian monsoon, and positive anomalies are associated with a dry monsoon. Calculations using the reanalysis enable the construction of a numerical algorithm of the interaction of outgoing longwave radiation, convection, and precipitation rates in the monsoon regions. The results obtained in this work are important in the verification of corresponding parametrizations of numerical atmospheric models.
Air Temperature and Atmospheric Precipitation Fields in the Regions with a Sparse Measurement Network (with a Reference to the Lena River Basin)
A. V. Kislov, A. G. Georgiadi, L. I. Alekseeva, and O. P. Borodin
A technique for spatial detailing of temperature and precipitation aimed at correcting archive data is developed. It is based on topographic, reflective, and other characteristics of the surface. A detailed areal distribution of monthly mean temperature and precipitation is derived for the Lena River basin, a region which is extremely irregularly and poorly covered by meteorological observational data.
A Mesoscale Structure of Meteorological Fields in the Tropopause Layer and in the Lower Stratosphere over the Southern Tropics (Brazil)
G. N. Shur, N. M. Sitnikov, and A. V. Drynkov
Some results of studying thermodynamics of the tropical tropopause and lower stratosphere performed with the help of the stratospheric M-55 Geofizika research aircraft during the international TROCCINOX experiment in 2005 in Brazil are considered. New data on a mesoscale structure of the wind, temperature, and humidity fields over the continental tropics are derived.
Prediction of Severe Winds and Rainfalls in Western Siberia Using Plane Rotations
L. N. Romanov and E. G. Bochkareva
A statistical model for prediction of hazardous phenomena such as severe winds and heavy rainfalls is described. The pattern recognition method based on direct minimization of the errors of recognition is used as the main instrument for modeling and prediction. The construction of the hyperplanes based on error minimization is performed with simultaneous screening of the initial parameters using the same criterion. The algorithm elaborated takes into account different error prices for different kinds of errors and thus effectively distinguishes the “domain” in some multidimensional space of the situations determined as “dangerous.” The domain may be confined by several hyperplanes the number of which depends on the distribution of dangerous situations in multidimensional space. The model comprises the accommodation that takes into account the development of the phenomenon in time and space. The construction was carried out for prediction of winds and rainfall 24 and 36 h in advance for four administrative districts of Western Siberia.