Thermodynamic conditions of hazardous convective phenomena at the Vostochny Cosmodrome

The wind parameters at the earth's surface and in the free atmosphere can have a significant impact on the progress with space rocket (SR) in the period of the preparation at the launch site, the launch processing and flight. Therefore, the above parameters are reflected in the operational documentation for each SR as critical and are constantly monitored by meteorological services of a spaceport at all stages of preparation and launch of the space rocket, as the cost of transferring one start of a space rocket is quite a significant amount of money. In connection with the construction of the new cosmodrome Vostochny, Amur Oblast should have a more detailed study of the state of the atmosphere in the days with dangerous convective phenomena. For this study, a database of thunderstorm days above the meteorological stations in the area of the cosmodrome Vostochny for 1985-2013 was made. It was found that Amur Oblast is characterized by a moderate thunderstorm activity. During the summer every year there are 20-25 days with thunderstorms. An increase in the variability of thunderstorm activity and a tendency to thunderstorm activity increase have been determined. Forecast of such dangerous convective phenomena like thunderstorms, hail, heavy rainfall is based on the analysis of the profiles of atmospheric temperature and humidity, which are recorded by aerological radiosondes. According to the results sensing characteristics of atmospheric instability are calculated: Indexes LIFT SWEET, KIND, TOTL and CAPE. The values of the index assesses the set of temperature and humidity of the atmosphere and wind parameters that are important signs of development of convection. By variability index values probability of dangerous convective phenomena is estimated. The second objective of the present study was to determine the possibility of using these indexes to determine the degree of stability of the atmosphere in the forecast of thunderstorms over Amur Oblast. According to the upper-air sounding, index values were calculated of atmospheric instability in days with thunderstorms and heavy rain. A comparative analysis of the indexes of atmospheric instability in the days classified as "thunderstorms and rain" and "heavy rain" are presented. The values of the probability of thunderstorms and rain storms without different values of the indexes of atmospheric instability are calculated. An analysis of the differences in the values of the index volatility typical for Amur Oblast and the values obtained for other territories is presented. Discriminant analysis of instability index to separate these two categories of dangerous convective phenomena in the atmosphere is made.

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