Changes in the percentages of eight main surface wind directions at 14 meteorological stations in Estonia, Northeast Europe, were studied during 1966–2008. Long-term changes in wind directions are related to variations in the large-scale atmospheric circulation but partly also to changes in the surroundings of the stations and in wind obstacles. Significant alterations in wind directions were determined, and found to be the strongest in the winter season. The percentages of W and SW winds have clear positive trends, while SE, E and NE winds are characterized by negative tendencies in winter. In conclusion, wind directions have probably been shifted from east to west. Differences in trends between the stations are explained by changes in wind obstacles around the stations. The trends in wind roses in Estonia were caused by the intensification of the westerly circulation over the Atlantic/European sector during the winter season.
Alexandersson, H., Schmith, T., Iden, K. & Tuomenvirta, H. 1998. Long-term variations of the storm climate over NW Europe. The Global Atmosphere and Ocean System, 6, 97–120.
Alexandersson, H., Tuomenvirta, H., Schmith, T. & Iden, K. 2000. Trends of storms in NW Europe derived from an updated pressure data set. Climate Research, 14, 71–73.
http://dx.doi.org/10.3354/cr014071
Barnston, A. G. & Livezey, R. E. 1987. Classification, seasonality and persistence of low-frequency atmospheric circulation patterns. Monthly Weather Review, 115, 1083–1126.
http://dx.doi.org/10.1175/1520-0493(1987)115<1083:CSAPOL>2.0.CO;2
Bärring, L. & Fortuniak, K. 2009. Multi-indices analysis of southern Scandinavian storminess 1780–2005 and links to interdecadal variations in the NW Europe–North Sea region. International Journal of Climatology, 29, 373–384.
Bärring, L. & von Storch, H. 2004. Scandinavian storminess since about 1800. Geophysical Research Letters, 31, L20202.
Bijl, W., Flather, R., de Ronde, J. G. & Schmith, T. 1999. Changing storminess? An analysis of long-term sea level data sets. Climate Research, 11, 161–172.
http://dx.doi.org/10.3354/cr011161
Feldstein, S. B. 2002. The recent trend and variance increase of the annular mode. Journal of Climate, 15, 88–94.
http://dx.doi.org/10.1175/1520-0442(2002)015<0088:TRTAVI>2.0.CO;2
Frank, H. P. & Landberg, L. 1997. Modelling the wind climate of Ireland. Boundary-Layer Meteorology, 85, 359–378.
http://dx.doi.org/10.1023/A:1000552601288
Goossens, D. & Gross, J. 2002. Similarities and dissimilarities between the dynamics of sand and dust during wind erosion of loamy sandy soil. CATENA, 47, 269–289.
http://dx.doi.org/10.1016/S0341-8162(01)00188-6
Heino, R., Tuomenvirta, H., Vuglinsky, V. S., Gustafsson, B. G., Alexandersson, H., Bärring, L., Briede, A., Cappelen, J., Chen, D., Falarz, M., Førland, E. J., Haapala, J., Jaagus, J., Kitaev, L., Kont, A., Kuusisto, E., Lindström, G., Meier, H. E. M., Miętus, M., Moberg, A., Myrberg, K., Niedżwiedż, T., Nordli, Ø., Omstedt, A., Orviku, K., Pruszak, Z., Rimkus, E., Russak, V., Schrum, C., Suursaar, Ü., Vihma, T., Weisse, R. & Wibig, J. 2008. Past and current climate change. In Assessment of Climate Change for the Baltic Sea Basin (Bolle, H.-J., Menenti, M. & Rasool, I., eds), pp. 35–131. Springer-Verlag, Berlin, Heidelberg.
http://dx.doi.org/10.1007/978-3-540-72786-6_2
Hurrell, J. W. 1995. Decadal trends in the North Atlantic oscillation: regional temperatures and precipitation. Science, 269, 676–679.
http://dx.doi.org/10.1126/science.269.5224.676
Hurrell, J. W. & van Loon, H. 1997. Decadal variations in climate associated with the North Atlantic Oscillation. Climatic Change, 36, 301–326.
http://dx.doi.org/10.1023/A:1005314315270
Hurrell, J. W., Kushnir, Y., Ottersen, G. & Visbeck, M. 2003. An overview of the North Atlantic Oscillation. The North Atlantic Oscillation: climate significance and environmental impact. Geophysical Monograph Series, 134, 1–35.
http://dx.doi.org/10.1029/134GM01
Jaagus, J. 2006. Climatic changes in Estonia during the second half of the 20th century in relationship with changes in large-scale atmospheric circulation. Theoretical and Applied Climatology, 83, 77–88.
http://dx.doi.org/10.1007/s00704-005-0161-0
Jaagus, J. 2009. Long-term changes in frequencies of wind directions on the western coast of Estonia. Publications of the Institute of Ecology, Tallinn University, 11, 11–24 [in Estonian, with English summary].
Jones, P. D., Jónsson, T. & Wheeler, D. 1997. Extension to the North Atlantic Oscillation using early instrumental pressure observations from Gibraltar and South-West Iceland. International Journal of Climatology, 17, 1433–1450.
http://dx.doi.org/10.1002/(SICI)1097-0088(19971115)17:13<1433::AID-JOC203>3.0.CO;2-P
Keenlyside, N. S., Latif, M., Jungclaus, J., Kornblueh, L. & Roeckner, E. 2008. Advancing decadal-scale climate prediction in the North Atlantic sector. Nature, 453, 84–88.
http://dx.doi.org/10.1038/nature06921
Keevallik, S. 2008. Wind speed and velocity in three Estonian coastal stations 1969–1992. Estonian Journal of Engineering, 14, 209–219.
http://dx.doi.org/10.3176/eng.2008.3.02
Keevallik, S. & Rajasalu, R. 2001. Winds on the 500 hPa isobaric level over Estonia (1953–1995). Physics and Chemistry of the Earth (B), 26, 425–429.
Kull, A. 2005. Relationship between inter-annual variation of wind direction and wind speed. Publicationes Instituti Geographici Universitatis Tartuensis, 97, 62–70.
Landberg, L. & Watson, S. J. 1994. Short-term prediction of local wind conditions. Boundary-Layer Meteorology, 70, 171–195.
http://dx.doi.org/10.1007/BF00712528
Lehmann, A., Getzlaff, K. & Harlass, J. 2011. Detailed assessment of climate variability in the Baltic Sea area for the period 1958 to 2009. Climate Research, 46, 185–196.
http://dx.doi.org/10.3354/cr00876
Li, J. & Wang, J. 2003. A new North Atlantic Oscillation index and its variability. Advances in Atmospheric Sciences, 20, 661–676.
http://dx.doi.org/10.1007/BF02915394
Matulla, C., Schöner, W., Alexandersson, H., von Storch, H. & Wang, X. L. 2008. European storminess: late nineteenth century to present. Climate Dynamics, 31, 125–130.
http://dx.doi.org/10.1007/s00382-007-0333-y
Mortensen, N. G. & Petersen, E. L. 1998. Influence of topographical input data on the accuracy of wind flow modeling in complex terrain. In Proceedings of the 1997 European Wind Energy Conference and Exhibition, pp. 317–320.
Orviku, K., Jaagus, J., Kont, A., Ratas, U. & Rivis, R. 2003. Increasing activity of coastal processes associated with climate change in Estonia. Journal of Coastal Research, 19, 364–375.
Perera,M. D. A. E. 1981. Shelter behind two-dimensional solid and porous fences. Journal of Wind Energy and Industrial Aerodynamics, 8, 93–104.
http://dx.doi.org/10.1016/0167-6105(81)90010-6
Reutter, K., Flay, R. G. J. & McIntosh, E. M. 2005. An application of the WAsP program in complex, forested terrain as part of a wind farm feasibility study. Wind Engineering, 29, 491–502.
http://dx.doi.org/10.1260/030952405776234562
Räämet, A., Suursaar, Ü., Kullas, T. & Soomere, T. 2009. Reconsidering uncertainties of wave conditions in the coastal areas of the northern Baltic Sea. Journal of Coastal Research, 56, 257–261.
Semenov, V. A., Latif, M., Dommenget, D., Keenlyside, N. S., Strehz, A., Martin, T. & Park, W. 2010. The impact of North Atlantic–Arctic multidecadal variability on Northern Hemisphere surface air temperature. Journal of Climate, 23, 5668–5677.
http://dx.doi.org/10.1175/2010JCLI3347.1
Serreze, M. C., Walsh, J. E., Chapin, F. S., Osterkamp, T., Dyurgerov, M., Romanovsky, V., Oechel, W. C., Morison, J., Zhang, T. & Barry, R. G. 2000. Observational evidence of recent change in the northern high-latitude environment. Climatic Change, 46, 159–207.
http://dx.doi.org/10.1023/A:1005504031923
Slonosky, V. C., Jones, P. D. & Davies, T. D. 2001. Atmospheric circulation and surface temperature in Europe from the 18th century to 1995. International Journal of Climatology, 21, 63–75.
http://dx.doi.org/10.1002/joc.591
Soomere, T. & Keevallik, S. 2001. Anisotropy of moderate and strong winds in the Baltic Proper. Proceedings of the Estonian Academy of Sciences, Engineering, 7, 35–49.
Soomere, T. & Zaitseva, I. 2007. Estimates of wave climate in the northern Baltic Proper derived from visual wave observations at Vilsandi. Proceedings of the Estonian Academy of Sciences, Engineering, 13, 48–64.
Taylor, P. A. & Salmon, J. R. 1993. A model for the correction of surface wind data for sheltering by upwind obstacles. Journal of Applied Meteorology, 32, 1683–1694.
http://dx.doi.org/10.1175/1520-0450(1993)032<1683:AMFTCO>2.0.CO;2
Thompson, D. W. & Wallace, J. M. 1998. The Arctic Oscillation signature in the wintertime geopotential height and temperature fields. Geophysical Research Letters, 25, 1297–1300.
http://dx.doi.org/10.1029/98GL00950
Thompson, D. W., Wallace, J. M. & Hegerl, G. C. 2000. Annular modes in the extratropical circulation. Part II: trends. Journal of Climate, 13, 1018–1036.
http://dx.doi.org/10.1175/1520-0442(2000)013<1018:AMITEC>2.0.CO;2
Troen, I. 1990. A high resolution spectral model for flow in complex terrain. In Proceedings, Ninth Symposium on Turbulence and Diffusion, Roskilde, Denmark, April 30–May 3, pp. 417–420. American Meteorological Society, Riso National Laboratory, Denmark.
Troen, I. & Petersen, E. L. 1989. European Wind Atlas. Risø National Laboratory, Roskilde. 656 pp.