Recent trends in Lake Ladoga ice cover
The condition of the ice on a large lake is an important sensitive indicator of regional climate change. We have investigated the ice regime on Lake Ladoga using aircraft surveys and satellite images. Nearly 1,000 surveys of the lake’s ice cover covering the years from 1943 to the present were analyzed to determine the first basic statistical characteristics of Ladoga ice cover based on long-term observation. The aim was to estimate long-term trends in the ice cover. Analysis showed that the average period of ice-cover formation is up to 1.5 times longer than the period of ice-cover destruction. The inter-annual trends in first and last ice dates, and in the duration of ice cover, are a few days per century, i.e. significant but rather small. We created the Relative Ice Cover Index (RICI), a dimensionless single-number variable that allowed the characteristics of winter seasons to be compared. A statistically significant downward trend of no more than 12% in RICI was observed over the 63-winter periods. The distribution of RICI was compared with the North Atlantic Oscillation Index (NAO) in an effort to explain the ice cover trend.
KeywordsLake Ladoga Ice cover Climatic trend
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- Lebedev, V. V. & P. L. Medres, 1966. Ledovyi rezhim Ladozhskogo ozera po materialam aviarazvedok. Sbornik rabot Leningradskoi GMO 3: 135–182. (Lake Ladoga ice covers condition by the aircraft surveys data. In Russian).Google Scholar
- Medres, P. L., 1957. Ledovyi rezhim Ladozhskogo ozera po materialam aviarazvedok, Vol. 66. Trudy GGI, Gidrometeoizdat, Leningrad, 92–140. (Lake Ladoga ice cover conditions by the aircraft surveys data. In Russian).Google Scholar
- Nõges, T., 2004. Reflection of the changes of the North Atlantic Oscillation Index and Gulf Stream Position Index in the Hydrology and phytoplankton of Võrtsjarv, a large, shallow lake in Estonia. Boreal Environment Research 9:401–407.Google Scholar
- Tikhomirov, A. I., 1966. Raschet sredniykh mesyachnykh temperatur poverkhnosti vody Ladozhskogo ozera. In Malinina, T. I. (ed.), Gidrologicheskii rezhim i vodnyi balans Ladozhskogo ozera. Lengosuniversitet, 279–323. (Lake Ladoga mean monthly water surface temperatures calculation. In Russian.).Google Scholar
- Usachev, V. F., V. G. Prokacheva & V. V. Borodulin, 1985. Otsenka dinamiki ozernykh l’dov, snezhnogo pokrova i rechnykh razlivov distantsionnymi sredstvami. Gidrometeoizdat, Leningrad, 103 pp. (The lake ice dynamics, snow covering and river floods estimation by remote sensing. In Russian).Google Scholar
- Wang, K., M. Leppäranta & A. Reinart, 2006. Modeling ice dynamics in Lake Peipsi. Verhandlungen der internationalen Vereinigung fur Limnologie 29: 1443–1446.Google Scholar