Estimation of modern climate trends and their synchronicity in the Altai region

At present regional assessment of the climate change parameter is an urgent problem of research. The article provides an analysis of changes in the dynamics of temperature and precipitation on the current data from the stations of the Altai region. There is a change in the dynamics of temperature after 1998 from warming to cooling mainly due to colder winters and cooler summers. Stations in the north and north-east of the territory have the slowest reaction to the changes. The cooling trend proved to be the strongest at the stations of the Pre-Altai plain and Kosh-Agach. The change of trends is consistent with the change of circulation epochs. In the Altai region no explicit tendencies in the change of precipitation have been recorded. The spatial distribution of annual precipitation trends is often local. This is due to the extreme dependence of precipitation regime on the local conditions, especially on the orographic features of the area. In this paper an algorithm of integrated assessment of the spatial and temporal structure of territorial climate parameters is described, which is based on the representation of a climatic rank as a set of components generated by various factors and their relations. Decomposition of climatic ranks into components allows evaluating the contribution of each constituent to the overall variability of the rank. At all the stations the greatest contribution to the overall variability of temperature is by annual variation (over 90%). The share of variability described by hidden periodicities is about 1.3% on average. It is much more than the trends influence, which for most stations does not exceed 0.3%. Rests and seasonal variation make the main contribution to the overall variability of sums of precipitation. The component formed by periodicities of various scale makes a significant contribution (on average about 10% in the territory). Thus, for modelling and prediction of the temperature and humidity regime of the territory, in addition to trends and annual variations, cyclical components of the time series must be taken into account. High interdependency of the long-term trend and seasonal component of temperature and precipitation at all stations with a typical distribution is identified. It shows that major changes in climatic parameters and seasonal variations in the region occur synchronously, being formed by the global processes. In order to optimise the presentation of the material and find homogeneous climatic changes in the Altai, the temperature and precipitation fields were classified. The temperature fields have 4 classes, with expressed geographical location, reflecting the common factors of their formation. Classification of precipitation fields in the region is largely determined by the lay of the land. The research reveals that changes in climatic characteristics of the region occur synchronously. Maximum synchrony of variability within the classes is observed.

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