Impact of the North Sea – Caspian Pattern on the formation of regimes of air temperature and precipitation in the Caucasus region

Е.А. Rybak1,2, N.A. Yaitskaya1,2, O.О. Rybak1,2

1 Sochi Research Center of RAS, Sochi, Teatralnaya St., 8a

  E-mail: elena.rybak@gmail.com

2 Branch of Institute of Natural and Technical Systems, Sochi, Kurortny Ave., 99/18

DOI: 10.33075/2220-5861-2018-3-57-64

UDC 551.582

Abstract:

   In this paper, we consider links between characteristics of the regional climate with one of quasi-stable modes of the atmospheric circulation, the North Sea-Caspian Pattern (NCP). The NCP index is calculated as a normalized residual between 500 mb geopotential heights in the centers of action in the North Sea and in the northern part of the Caspian Sea. When the phase of the NCP is positive, the atmospheric circulation in the region has a more pronounced meridional character. In case the phase is negative, the circulation is mostly of the zonal character. During positive phase in winter period, prevailing northern air flows over the greater part of the Eastern Europe, over the Black Sea and over the Caspian Sea, result in substantial temperature decrease with respect to climatic means. During negative phases, the pattern is reverse. Air temperature anomalies are characterized by relatively high spatial correlation because they are formed under the influence of the large-scale atmospheric circulation. At the same time, precipitation regime is highly influenced by the local conditions and therefore has low spatial correlation.

   The purpose of the research is to evaluate possibility of disposal of an expected NCP phase for prediction of surface air temperature and precipitation rate, especially in the mountain regions of the South of Russia and, as well, to use them as input meteorological variables in the mathematical models of mountain glaciers’ dynamics.

   The region of interest covers the southern part of European Russia to the south of the line connecting Rostov and Volgograd including the Black Sea and the Sea of Azov coastal zones. We analyzed records of surface air temperature and precipitation rates from 31 regular meteorological stations in the region under discussion. Original 3-hour data were averaged over winter months (December-January-February), summer months (June-July-August), cold part of the year (from October to March), warm part of the year (from April to September) and over the whole year.

   The research revealed that the temperature regime in the mountain and piedmont areas of the Caucasus in winter season and in the cold part of the year is formed mostly under the influence of anomalous atmospheric circulation associated with the positive or with the negative phase of the NCP. During the summer period impact of the NCP on the temperature regime is small. Precipitation regime depends mostly on the local conditions, especially in summer months, when correlation coefficient does not exceed 0,3. Basing on the research results one can conclude that the NCP is not an appropriate predictor for precipitation. On the contrary, it can be used as a predictor of the air temperature in the cold part of the year. It is expedient to use, for instance, strong linear correlation of the NCP index and air temperature for detailing regional seasonal predictions. Particularly, in the surroundings of Sochi and Krasnaya Polyana the lower 95% confidential interval of correlation coefficient is |R|³0,6. It means that close relationship between the NCP and air temperature can be applied for establishing prognostic estimates of avalanche situation. This possibility is essentially important for planning mountain ski industry not only for resorts in the region of Krasnaya Polyana but also for the whole Central and Western Caucasus.

Keywords: climate, regional climate, air temperature, precipitation amount, climate prediction, Caucasus.

Full text in PDF (RUS)

LIST OF REFERENCES

  1. Molavi-Arabshahi M., Arpe K., Leroy S.A.G. Precipitation and temperature of the southwest Caspian Sea region during the last 55 years: their trends and teleconnections with large-scale atmospheric phenomena // International Journal of Climatology. 2016. V. 36. P. 215
  2. Kutiel H., Benaroch Y. North Sea Caspian Pattern (NCP) – an upper level atmospheric teleconnection affecting the eastern Mediterranean: Identification and definition // Theoretical and Applied Climatology. 2002. V. 71. P. 17–28.
  3. Kutiel H., Maheras P., Türkes M., Paz S. North Sea Caspian Pattern (NCP) – an upper level atmospheric teleconnection affecting the eastern Mediterranean: Implications on the regional climate // Theoretical and Applied Climatology. 2002. V. 72. P. 173–192
  4. Lurie P. M. and Panov V. D. Changes in the modern glaciation of the Northern slope of the Greater Caucasus in the twentieth century and the forecast of its degradation in the twenty-FIRST century, Meteorology and hydrology, no. 4, P. 68-76.
  5. Khromova T., Nosenko G., Kutuzov S., et al. Glacier area changes in Northern Eurasia // Environmental Research Letters. V. 9. P. 1–11.
  6. Chernomorets S. S., Petrakov D. A., Krylenko I. V., etc. Dynamics of the Bashkar glacial-lake complex and mudflow hazard assessment in the Adyl-su river valley (Caucasus) / / earth’s Cryosphere. 2007. Vol. 11. No. 1. P. 72-84
  7. Petrakov D.A., Tutubalina O.V., Aleinikov A.A. et al. Monitoring of Bashkara Glacier Lakes (Central Caucasus, Russia) and modeling of their potential outburst // Natural Hazards. 2012. V. 61. No 3. P.1293–1316.
  8. Auer I., Matulla C., Boehm R. et al. Sensitivity of Frost Occurence to Temperature Variablity in the European Alps // International Journal of Climatology. 2005. V. 1749–1766.
  9. Brunetti M., Kutiel H. The relevance of the North-Sea Caspian Pattern (NCP) in explaining temperature variability in Europe and the Mediterranean // Natural Hazards and Earth System Sciences. 2011. V. 11. 2881-2888.
  10. Brunetti M., Maugeri M., Monti F., Nanni T. Temperature and precipitation variability in Italy in the last two centuries from homogenized instrumental time series // International Journal of Climatology. 2006. V. 26. P. 345–381.
  11. Efthymiadis D., Goodess C.M., Jobes P.D. Trends in Mediterranean gridded temperature extremes and large-scale circulation influences // Natural Hazards and Earth System Sciences. 2011. V. 11. P.2199–2214.
  12. Kutiel H., Türkes M. New evidence for the role of the North Sea – Caspian pattern on the temperature and precipitation regimes in continental Central Turkey // Geografiska Annaler. 2005. 87A. P.501–513.
  13. Polonsky A. B., Kibalchich I. A. Influence of the North Sea-Caspian oscillation on surface temperature anomalies over the territory Ukraine and the Black Sea in the cold period // Scientific Bulletin of the Belgorod state University. Series “Natural Sciences”. 2013. Issue 25, No. 24 (167), P. 150-156.
  14. Polonsky A. B., Kibalchich I. A. Joint influence of the main modes of variability in the Ocean-Atmosphere system in the Atlantic-European sector on temperature anomalies in Ukraine and the Azov-black sea region in the winter period. 2014. No. pp. 329-333.
  15. Polonsky A. B., Kibalchich I. A. Interannual variability of atmospheric circulation and temperature anomalies in Eastern Europe in winter // Reports of the National Academy of Sciences of Ukraine. 2014. No. 6. P. 100-107.
  16. Polonsky A. B., Kibalchich I. A. Circulation indices and temperature regime of Eastern Europe in winter // Meteorology and hydrology. 2015. no. 1. P. 5-17.
  17. Kibalchich I. A. Features of the General circulation of the atmosphere and their influence on the formation of temperature anomalies in Ukraine: dis. … Cand. geogr. Sciences. Odessa, 2015. P. 181.
  18. Privalsky V. E. Climate variability (stochastic variability, predictability, spectra). Moscow: Nauka, 1985, P. 183.
  19. Rybak O. O., Rybak E. A., Popovnin V. V., etc. Snow cover formation in the Krasnaya Polyana region (Sochi) in the winter of 2016-2017. Part 2. Meteorological conditions and avalanche situation // Polythematic network electronic scientific journal of Kubgau (Scientific journal of Kubgau) [Electronic resource]. – Krasnodar: Kubgau, 2017. No. 131 (07) access Mode: http://ej.kubagro.ru/2017/07/pdf/45.pdf.

If you have found a spelling error, please, notify us by selecting that text and pressing Ctrl+Enter.

Translate »

Spelling error report

The following text will be sent to our editors: