Identification of the surface temperature change in the Atlantic-European and Mediterranean regions using ERA5 re-analysis

A.B. Polonsky, S.S. Beytser

 Institute of Natural and Technical Systems, RF, Sevastopol, Lenin St., 28


DOI: 10.33075/2220-5861-2021-1-18-24

UDC 551.524.3 


   The article analyzes the seasonal, interannual and inter-decadal variability of the surface / drive temperature of the Atlantic-European and Mediterranean regions, as well as assesses temperature trends. The information is based on the data of the re-analysis of ERA5. This is one of the latest climate re-analyses, which was performed by specialists of the European Center for Medium-term Weather Forecasts (ECMWF) with a spatial resolution of 0.25°x0.25°. We analyzed hourly data for 41 years, from 1979 to 2019 for two periods: the entire re-analysis period and the thirty-year climate period from 1990 to 2019. The purpose of the analysis was to clarify the relative role of natural quasi-periodic changes in temperature and the trend component of presumably anthropogenic origin. The most important role of natural temperature changes on time scales from interannual to inter-decennial is confirmed. Linear temperature trends calculated over the last climate period of thirty years are responsible for the increase in temperature over the mainland areas to 3°C over 30 years. At the same time, over a significant part of the north-eastern Atlantic and adjacent land areas, the linear trends estimated over a thirty-year period are insignificant. Natural quasi-periodic components of variability prevail here. As the analyzed period increases, the areas of significant temperature trends expand. In the area of the Canary and Portuguese upwelling, a decrease in the driving temperature is observed, confirming the validity of the hypothesis of A. Bakun of the intensification of the eastern coastal upwelling systems in the contemporary climate epoch.

Keywords: temperature trends, interannual and interdecadal variability.

To quote: Polonsky, A.B., and S.S. Beytser. “Identification of the Surface Temperature Change in the Atlantic-European and Mediterranean Regions Using ERA5 Re-Analysis.” Monitoring Systems of Environment no. 1 (March 25, 2021): 18–24. doi:10.33075/2220-5861-2021-1-18-24.

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  1. IPCC: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I To the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Solomon, D. Qin, M. Manning, Ed. Cambridge. Cambridge University Press. 2007. 996 p.
  2. IPCC: Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change Core Writing Team, K. Pachauri and L.A. Meyer (eds.). IPCC. Geneva. Switzerland. 151 p.
  3. Knight J., Allan R., Folland C., et al. A signature of Persistent Natural Thermohaline Circulation Cycles in Observed Climate. Geophysical Research Letters. 2005. Vol. L20708.
  4. Kushnir Y. Interdecadal variations in North Atlantic sea surface temperature and associated atmospheric conditions. of Climate. 1994. Vol. 7. Nо. 1. pp. 141– 157.
  5. Schlesinger M. E., Ramankutty N. An oscillation in the global climate system of period 65-70 years. Nature. 1994. Vol. 367. pp. 723–726.
  6. Ljungqvist F.C. A New Reconstruction of Temperature Variability in the Extra-Tropical Northern Hemisphere During the Last Two Millennia. Geogr. Ann. 2010. Vol. 92. pp. 339–351.
  7. Semenov V.A., Mohov I.I., Polonskij A.B. Modelirovanie vlijanija estestvennoj dolgoperiodnoj izmenchivosti v Severnoj Atlantike na formirovanie anomalij klimata v Severnom polusharii. Morskoj gidrofizicheskij zhurnal. 2014. No 4. pp. 14–27.
  8. Polonskij A.B. Atlanticheskaja mul’tidekadnaja oscilljacija i ee projavlenija v Atlantiko-Evropejskom regione. Morskoj gidrofizicheskij zhurnal. 2008. No 4. pp. 69–79.
  9. Polonsky A. The Ocean’s Role in Climate Change / Cambridge Scholars Publishing. Newcastle-Upon-Tyne, UK. 2019. 294 p.
  10. Jelektronnyj resurs: (data obrashhenija: 02.02.2021).
  11. Jelektronnyj resurs: (data obrashhenija: 02.02.2021).
  12. Bejcer S.S., Polonskij A.B. Svidetel’stvo o gosudarstvennoj registracii programmy na JeVM № 2021612094. Monitoring izmenenija prizemnoj temperatury vozduha. Data registracii: 11.02.2021.
  13. Koltermann, K. P., Gouretski, V., Jancke, K. Hydrographic Atlas of the World Ocean Circulation Experiment (WOCE) Vol. 3: Atlantic Ocean. Scripps Institution of Oceanography. US. 2011.
  14. Jelektronnyj resurs: (data obrashhenija: 02.02.2021).
  15. WMO Region VI (Europe, Continent only): Highest Temperature. World Meteorological Organization. 2020.
  16. Bakun A. Global climate change and intensification of coastal ocean upwelling. Science. 1990. Vol. 247. pp. 198–201. DOI:10.1126/science.247.4939.198.
  17. Polonskij A.B., Serebrennikov A.N. Mnogoletnie tendencii v izmenenii temperatury poverhnosti okeana v zone Kanarskogo apvellinga i ih prichiny. Issledovanija Zemli iz kosmosa. 2018. No 3. pp. 93–100. DOI:10.7868/S0205961418030077.