Seasonal and diurnal variations of wind parameters at Pakri; pp. 227–239
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doi: 10.3176/eng.2009.3.06Authors
Sirje Keevallik, Tarmo Soomere
Abstract
Long-term, seasonal, and diurnal variations of the wind speed in 1969–1992 are analysed for a homogeneous wind data set from Pakri, located on the North Estonian coast in the western part of the Gulf of Finland, the Baltic Sea. Interannual variations of the annual mean wind speed are mostly ± 1 m/s from the overall average (5.1 m/s). Seasonal variations of the monthly mean wind speed have the same magnitude. No clear trend in the annual mean wind speed existed in 1966–1992 and a drastic drop in the respective value in 1993 stems from the relocation of the measurement site. Wind speed frequency distributions vary during the year showing the largest seasonal differences for west and north-west winds. While there is almost no dependence of the wind speed on the measurement time in winter and in autumn, there is a large daily cycle in spring and summer with values deviating by ± 0.75 m/s from the average.
References
1. Keevallik, S. Possibilities of reconstruction of the wind regime on Tallinn Bay. Proc. Estonian Acad. Sci. Eng., 2003, 9, 209–219.
2. Soomere, T. and Keevallik, S. Directional and extreme wind properties in the Gulf of Finland. Proc. Estonian Acad. Sci. Eng., 2003, 9, 73–90.
3. Savijärvi, H., Niemela, S. and Tisler, P. Coastal winds and low-level jets: simulations for sea gulfs. Quart. J. Roy. Meteor. Soc. B, 2005, 131, 625–637.
doi:10.1256/qj.03.177
4. Soomere, T. Anisotropy of wind and wave regimes in the Baltic Proper. J. Sea Res., 2003, 49, 305–316.
doi:10.1016/S1385-1101(03)00034-0
5. Elken, J., Kask, J., Kõuts, T., Liiv, U., Perens, R. and Soomere, T. Hydrodynamical and geological investigations of possible deep harbour sites in north-western Saaremaa Island: overview and conclusions. Proc. Estonian Acad. Sci. Eng., 2001, 7, 85–98.
6. Waters, R., Engström, J., Isberg, J. and Leijon, M. Wave climate off the Swedish west coast. Renewable Energy, 2009, 34, 1600–1606.
doi:10.1016/j.renene.2008.11.016
7. Handbook of Climate of the USSR, Vol. 4: Estonian SSR, Part 3: Wind. Gidrometeoizdat, Leningrad, 1966 (in Russian).
8. Eesti NSV kliimaatlas. Eesti NSV Hüdrometeoroloogia Teenistuse Valitsus, Tallinn, 1969.
9. Kull, A. Eesti tuuleatlas. Tartu Ülikool, 1996.
10. Soomere, T. and Keevallik, S. Anisotropy of moderate and strong winds in the Baltic Proper. Proc. Estonian Acad. Sci. Eng., 2001, 7, 64–78.
11. Soomere, T. Extreme wind speeds and spatially uniform wind events in the Baltic Proper. Proc. Estonian Acad. Sci. Eng., 2001, 7, 195–211.
12. Keevallik, S. Tuuled Tallinna lahel. Publicationes Instituti Geographici Universitatis Tartuensis, 2003, 93, 217–226.
13. Soomere, T., Myrberg, K., Leppäranta, M. and Nekrasov, A. The progress in knowledge of physical oceanography of the Gulf of Finland: a review for 1997–2007. Oceanologia, 2008, 50, 287–362.
14. Tomson, T. and Hansen, M. Seasonal wind stability on the West Estonian coast. Proc. Estonian Acad. Sci. Eng., 2001, 7, 212–221.
15. Mietus, M. (coordinator). The climate of the Baltic Sea Basin. Marine meteorology and related oceanographic activities, Report No. 41, World Meteorological Organisation, Geneva, 1998.
16. Tomson, T. and Lamp, H. Periodicity of the average wind shear. Proc. Estonian Acad. Sci. Eng., 2007, 13, 65–75.
17. Tomson, T. and Bergström, H. Periodical effects in the Baltic Proper. In Proc. Seminar on Offshore Wind Energy in Mediterranean and Other European Seas. Naples, 2003. CD-ROM, 11 p.
18. Keevallik, S. and Soomere, T. Shifts in early spring wind regime in North-East Europe (1955–2007). Clim. Past, 2008, 4, 147–152.
19. Achberger, C., Chen, D. L. and Alexandersson, H. The surface winds of Sweden during 1999–2000. Int. J. Climatol., 2006, 26, 159–178.
doi:10.1002/joc.1254
20. Holt, T. and Palutikof, J. P. Seasonal variations in the diurnal cycle of wind speed: implications for near-offshore wind farms. Geophys. Res. Abstr., 2003, 5, 10425.
