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A Study of Divergence and Convergence of the Wind Field over Europe and the Mediterranean

  • O. Pezoula
  • A. Bartzokas
Conference paper
Part of the Springer Atmospheric Sciences book series (SPRINGERATMO)

Abstract

In this work, the divergence and convergence of the wind field over Europe, the Mediterranean and North Africa is studied for the 60-year period 1950–2009. Mean monthly values (s−1) are utilized at 273 grid points, spaced by 2.5° × 2.5°, at 10 atmospheric pressure levels from 1,000 hPa up to 100 hPa. It is found that on a seasonal basis considerable differences appear among the various European regions both near the surface of the Earth and in the upper atmosphere. During winter, near the surface, high values of convergence appear in the cyclogenesis areas and along the tracks of depressions. Specifically: in the Mediterranean, with maximum values in the Gulf of Genoa, the Black Sea and from the North Sea up to the Baltic Sea. On the contrary, over the rest of the areas divergence prevails. This situation is reversed above approximately 600 hPa with positive values (divergence) over the Mediterranean and the Seas of northern Europe and negative (convergence) over central Europe. During summer, over the seas, where air is cooler than over land, positive values are observed (divergence). This difference is more intense over lower latitudes. Similarly to winter, in the upper atmosphere, the convergence-divergence field becomes smoother changing signs at about 600 hPa.

Keywords

Subtropical Anticyclone Height Rise High Pressure Level Atmosphere Stratum Heat Capacity Difference 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. Alpert P, Neeman BU, Shay-El Y (1990) Inter-monthly variability of cyclone tracks in the Mediterranean. J Clim 3:1474–1478. doi:10.1175/1520-0442(1990) 003<1474:IVOCTI>2.0.CO;2CrossRefGoogle Scholar
  2. Flocas HA, Simmonds I, Kouroutzoglou J, Keay K, Hatzaki M, Bricolas V, Asimakopoulos D (2010) On cyclonic tracks over the eastern Mediterranean. J Climate 23:5243–5257. doi:http://dx.doi.org/10.1175/2010JCLI3426.1 CrossRefGoogle Scholar
  3. Karoulias AS (1973) Saharan depressions. Dissertation, University of Thessaloniki (in Greek)Google Scholar
  4. Makroyannis TJ (1976) Tracks of anticyclonic systems in the Greek area. Dissertation, University of Thessaloniki (in Greek)Google Scholar
  5. Meteorological Office (1972) Meteorological glossary. Compiled by McIntosh DH, Her Majesty’s Stationary Office, LondonGoogle Scholar
  6. Schepanski K, Knippertz P (2011) Soudano-Saharan depressions and their importance for precipitation and dust: a new perspective on a classical synoptic concept. Q J R Meteorol Soc 137:1431–1445. doi: 10.1002/qj.850 CrossRefGoogle Scholar
  7. Varfi M (2009) Synoptic and dynamical study of warm and cold invasions in the broader area of Greece. Dissertation, University of Thessaloniki (in Greek)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Laboratory of Meteorology, Department of PhysicsUniversity of IoanninaIoanninaGreece

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