Peculiarities of formation and social-economic consequences of temperature risks in Tomsk Region

Current climate changes in Russia are attended by the increase in frequency of dangerous weather events. This involves an increase in economic and social losses. The systematic analysis of dangerous weather events (DWE) characteristics is required in order to launch a project on decreasing future and present losses associated with climatic risks. The estimation of probability of conditions caused by extreme temperatures in Tomsk Region and their social-economic consequences is given in this paper. The analysis of circulatory factors of forming DWE under study using peculiarities of elementary circulatory mechanisms by Dzerdzeevsky's typing is carried out. The data on diurnal air temperatures were collected at 10 stations located in Tomsk Region for the 1980-2009 period. The risk associated with dangerous weather events is treated as the frequency distribution function and DWE consequences. The indirect method for calculating social-economic components of risks was applied. In calculating, account was taken of the area exposed to DWE; its duration and degree of aggressiveness, population, GDP per capita. Temperature risks associated with such dangerous weather events as high / low temperature periods, abnormally cold / abnormally hot weather, severe cold / heatwave, were considered. For every DWE parameters such as the frequency of days with DWE per month and for a relevant year period; the frequency of years with DWE; average and maximal continuous duration of periods; period duration with criteria every 30, 50, 100 years; circulatory conditions of the appropriate DWE formation (by B.L. Dzerdzeevsky's typing) were calculated. It was found that more sustainable DWE caused by negative air temperatures were typical for Tomsk Region, northern and north-eastern areas being the most exposed. The implementation of the model based on simple Markov chains made it possible to get the predicted continuous duration of periods with DWE once every specified time period (30, 50, 100 years). From the experimental data on DWE frequency the calculation of social-economic risks was made for Tomsk Region. The calculations of social risks demonstrated that the dangerous weather events caused by extremely low temperatures contributed to the greatest social risk on a large scale for Tomsk and Kolpashevo Districts, which is caused, apart from geographical position, to a large extent, by the population. The results of indirect assessment of economic risks showed that their maximal values in forming either positive or negative extreme temperature periods were observed in Tomsk District, which is caused by the maximal density of the population against the other districts of the region. The analysis of macro-circulatory conditions contributing to the DWE formation in Tomsk region revealed that during the study period the extreme temperature conditions of the cold period were fixed in 84-94.6% days in meridional groups of circulation, with the meridional northern group prevailing. Active blocking processes which are associated with sustainable and aggressive weather anomalies occupying large territories are peculiar for this group of circulation. Abnormal temperature conditions during the warm period in Tomsk Region are formed predominantly in the anticyclone circulation or in the process of the flat pressure gradient formation. Elementary circulation mechanisms (ECM) 13w (winter) and 13s (summer) contribute to the temperature risk formation. The significant horizontal pressure gradients with ECM create favorable conditions for the meteorological extreme formation.

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