Том 44, № 6 (2019)

The estimates of changes in the frequency of atmospheric blocking based on the CMIP5 ensemble simulations with modern climate models of general circulation are obtained using various criteria of atmospheric blocking detection and different RCP scenarios of anthropogenic forcing for the 21st century. To assess the quality of the model simulation of atmospheric blocking characteristics, the meridional seasonal distributions of the blocking frequency are compared with reanalysis data. The results demonstrate that the choice of the ensembles of the best models (in terms of the blocking simulation for the modern climate) is important. For the best models, a risk of the blocking frequency increase in the warming climate is noted, which is not observed in the results for the full ensemble.

The detailed analysis of variations in sunshine characteristics in Moscow in 1955–2017 is provided using observational data from the Moscow State University Meteorological Observatory. The regression equations between sunshine duration and radiation characteristics are derived. The possibility of their application to different geographic regions is assessed.

Actual in situ observations at the Antarctic continental slope performed with eddy-resolving spatial resolution were used. As a result, some parameterizations were verified that describe the processes of instability of density flows on a sloping bottom derived during the laboratory experiments. These processes were identified based on observational data. Any changes in the bottom slope (local or general, linked to the transition of the steep slope into the deep-sea floor) lead to changes in the regime of dense water runoff. The resulting hydraulic jumps lead to the turbulent mixing and function as one of the main mechanisms of ventilation of deep and bottom water. In the areas of local bottom rubs, disturbances like leeward waves are sometimes observed at the dense water top. They cause the intrusive layering and subsequent occurrence of turbulence centers in the slope area; the eddy lenses which also take part in the slope water ventilation are sometimes observed over bottom rubs. A strong baroclinity of the Antarctic slope front (ASF) in a steep part of the slope is another mechanism of deep water ventilation. It leads to the instability of cascading, subsequent intrusive layering and eddy formation. The baroclinic instability is amplified by the increased dynamics of dense water runoff at the bottom slope increase. However, the realization of shear instability at density interface is possible but at the smaller spatial scale than the instability scales observed in the ASF area.

The review is compiled of the results of the total ozone (TO) monitoring in the CIS and Baltic countries that functions in the operational mode at the Central Aerological Observatory (CAO). The monitoring system uses data from the national net work equipped with M-124 filter ozonometers op er at -ing under the methodological supervision of the Main Geophysical Observatory. The quality of the functioning of the entire system is operation ally con trolled in CAO by the comparison with the observations obtained from the OMI satellite equipment (NASA, USA). Basic TO observation data are generalized for each month of the first quarter of 2019 and for the first quarter. Data of routine observations of surface ozone values in the Moscow region and Crimea are also considered.