On an abrupt sea surface temperature (sst) decrease in the Black Sea

A.B. Polonsky1,2,  N.S. Drobosuk2

1 Institute of Natural end Technical Systems, Russian Federation, Sevastopol, Lenin St., 28

Email: apolonsky5@mail.ru

2 Sevastopol Branch of Moscow State University, Russian Federation, Sevastopol

DOI: 10.33075/2220-5861-2018-3-42-49

UDC 551.465(262.5)

Abstract:

   The paper is devoted to the complex analysis of daily satellite data on sea surface temperature (SST) in the Black Sea from early 1980s and wind field from 1988. It is shown that abrupt Black Sea SST decrease (between 2 to 9°С per day) is a regular phenomenon. Such SST decreasing is typical not only for the coastal upwelling zones in spring-summer. Extended areas of such type arise in the vicinity of the western and eastern large-scale cyclonic gyres in the Black Sea. Transient (but not too fast) cyclonic atmospheric eddies passing through this region are the main cause of additional turbulent entrainment, upward motion in the upper sea layer and SST anomalies generation. These anomalies are usually developed  during a few days after stormy conditions. This mechanism is especially efficient when the extended blocking is formed over N-E part of Europe and cyclones are slowly moving along its periphery. Coefficient of correlation between cyclonic wind vortices and consequent regional SST decreasing in the eastern cyclonic Black Sea gyre exceeds 0.6. Frequency of the abrupt SST fall and anomalous area tend to be higher during recent 20 yrs as a result of intensified cyclonic activity in the Black Sea region since 1990s.

Keywords: sea surface temperature, wind field, satellite data, cyclonic vorticity in the low-troposphere.

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LIST OF REFERENCES

  1. Hydrometeorology and hydrochemistry of the seas of the USSR. Vol. 4: Black sea. Issue 1. Hydrometeorological conditions. Saint Petersburg: Gidrometeoizdat, 1991. P. 469.
  2. Hydrometeorology and hydrochemistry of the seas of the USSR. Vol. 4: Black sea. Issue 2. Hydrochemical conditions and Oceanological bases of biological productivity formation. Saint Petersburg: Gidrometeoizdat, 1992. P. 220.
  3. Oguz T. The role of physical processes controlling the Oxycline and Suboxic Layer structures in the Black Sea // Global Biogeochem. Cycles, 2002, 16 (2). doi: 10.1029/2001GB001465.
  4. Staneva J.V., Stanev E.V. Oceanic response to atmospheric forcing derived from different climatic data sets: intercomparison study for the Black sea // Oceanol. Acta. 1997. P. 393–417.
  5. Levenkova E. A., Polonsky A. B. Climatic characteristics of upwelling off the coast. Changes and their variability // Meteorology and hydrology. 2005. No. 5. P. 44-51.
  6. Polonsky A.В. Upwelling in the Northern Black Sea: Description, Mechanisms and Impact on Chlorophyll-A concentration / In book: Upwelling: Mechanisms, Ecological Effects and Threats to Biodiversity (Editors: Williams E. Fischer and Adams B. Green). Nova Science Publishers, Inc., New York, USA, 2013. Р. 59–76.
  7. AVHRR Pathfinder version 5.3 level 3 collated (L3C) global 4km sea surface temperature [Электронный ресурс]. – access mode: URL: https://data.nodc.noaa.gov/cgi-bin/ iso?id=gov.noaa.nodc:  AVHRR_Pathfinder-NCEI-L3C-v5.3 (date of request: 27.11.2017).
  8. AVHRR-Pathfinder/NASA’s Physical Oceanography Distributed Active Archive Cente [Электронный ресурс]. – access mode: https://podaac.jpl.nasa.gov/ AVHRR-Pathfinder (date of request: 01.04.2017).
  9. NOAA Satellite Data Access by Datasets [Электронный ресурс]. – режим доступа: https://www.ncdc.noaa.gov/data-access/satellite-data/satellite-data-access-datasets (date of request: 18.02.2018).
  10. Serebrennikov A. N. Analysis of modern satellite databases in the study of the Earth from space //  Monitoring systems of environment. Sevastopol: INTS. Issue 3 (23). 2016. P. 52-58.
  11. Polonsky A. B., Serebrennikov A. N. Interannual and intra-monthly fluctuations of the wind field and ocean surface temperature in the West African upwelling zone based on satellite data // Earth research from space, 2017, no. 5, P. 14-19.
  12. Polonsky A. B., Bardin M. Yu., Voskresenskaya E. H. Statistical characteristics of cyclones and anticyclones over the Black Sea in the second half of the XX century // Marine hydrophysical journal. 2007. no. 6. P. 47-58.
  13. Evstigneev V. P., Naumova V. A. Voskresenskaya E. N., etc. Wind-wave conditions of the coastal zone of the Azov-black sea region. Sevastopol: INTS. 2017. 320 p.

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