ИСТИНА

The Arctic is the region most sensitive to climate change on the globe, it concerns both phys-ical feedbacks in the climate system and ecological systems. However, the spatial distribution of the climate changes in the region is ambiguous, there are various estimates of certain meteorologi-cal parameters trends in different water areas and coastal zones of the Russian and foreign Arctic regions. Taking into account the increasing number of dangerous phenomena and outlooks for the Arctic coast and the Northern Sea Route development, the task of providing the region detailed hydrometeorological and climatic information with a horizontal resolution of at least several kilo-meters becomes particularly topical. As a tool for solving this task, it seems efficient to use region-al climate modeling. As a result of long-term climate experiments, an integrated archive of hydrometeorological parameters will be obtained for the first time in the Arctic for current climatic conditions with a spatial resolution of less than 5 km (regional reanalysis). The main tool is the well known regional non-hydrostatic model COSMO-CLM, the climate version of COSMO model. ERA-Interim glob-al reanalysis will be used as driving conditions for regional model. First verification over Russian Arctic hundreds stations have shown the best configuration of model and domains, including different model versions, spectral nudging, turbulent scheme op-tions and starting time of experiments. Many test experiments for summer and winter months were conducted. The default version without spectral nudging have shown the worst results – tempera-ture biases are about 1C, RMSE 3.5 – 4 C. There are specific large errors over the inland Eastern Siberia stations, because model has strongly underestimated winter boundary layer freezing. Switch on the spectral nudging reduced RMSE slightly, while many corrections in turbulent scheme options decreased RMSE significantly (up to 2.5 C for coastal stations, and 3 C for in-lands), and get slightly negative biases (approx. -0.5 C). Model version 5.05 has also shown reduc-ing of biases. The same estimations are for wind speed, but in general, biases are smaller. Since there are no significant differences between ERA-Interim and ERA5 driving conditions, the for-mer was chosen as basic reanalysis taking into account data volume. The near future long-term ex-periments with the chosen model configuration would be conducted. The spectral nudging tech-nique will be also applied within all simulations. Such detailed hydrometeorological fields in the Arctic over a long period (1980 – 2016) will provide new, more thorough and justified estimates of the current regional climate changes, as well as extreme weather events. This will provide broad opportunities for detailed climate assessments of Russian Arctic region, a research analysis of a large number of climate parameters during recent decades. In particular, the data can be used for environmental studies and the modern environmen-tal changes researches, e.g., for the construction of various buildings, infrastructure facilities on the coast and the sea shelf, long-term planning of maritime operations, safe navigation along the Northern Sea Route and many others. The scientific significance of this regional reanalysis is the possibility of using information as inputs to modeling the ocean's characteristics (wind waves and dynamics), coastal ecosystems (turbulent heat and moisture fluxes, greenhouse gases), experiments on more detailed research of individual phenomena on nested domains (extreme situations, hazardous weather events, etc.), analysis of trends in the frequency of occurrence of extreme events and features of their spatial distribution, the hydrometeorological regime of coastal areas studies, climatology and tracking of polar mesocyclones, etc. The scientific and applied importance of the used methodology is also its further application for downscaling of the global CMIP5 (or CMIP6) project climate projections and for detailed as-sessments of climate and environmental changes in the Arctic in the 21st century on a regional scale, accordingly.