Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 13 1 2009 10.5194/hess-13-17-2009 http://www.hydrol-earth-syst-sci.net/13/17/2009/ http://www.hydrol-earth-syst-sci.net/13/17/2009/hess-13-17-2009.html http://www.hydrol-earth-syst-sci.net/13/17/2009/hess-13-17-2009.pdf 17 25 2009-01-07 Interannual variability of winter precipitation in the European Alps: relations with the North Atlantic Oscillation. E. Bartolini elisa.bartolini@polito.it P. Claps P. D'Odorico Dipartimento di Idraulica, Trasporti e Infrastrutture Civili, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy Department of Environmental Sciences, University of Virginia, P.O. Box 400123, Charlottesville, VA 22903-4123, USA The European Alps rely on winter precipitation for various needs in terms of hydropower and other water uses. Major European rivers originate from the Alps and depend on winter precipitation and the consequent spring snow melt for their summer base flows. Understanding the fluctuations in winter rainfall in this region is crucially important to the study of changes in hydrologic regime in river basins, as well as to the management of their water resources. Despite the recognized relevance of winter precipitation to the water resources of the Alps and surrounding regions, the magnitude and mechanistic explanation of interannual precipitation variability in the Alpine region remains unclear and poorly investigated. Here we use gridded precipitation data from the CRU TS 1.2 to study the interannual variability of winter alpine precipitation. We found that the Alps are the region with the highest interannual variability in winter precipitation in Europe. This variability cannot be explained by large scale climate patterns such as the Arctic Oscillation (AO), North Atlantic Oscillation (NAO) or the East Atlantic/West Russia (EA/WR), even though regions below and above the Alps demonstrate connections with these patterns. Significant trends were detected only in small regions located in the Eastern part of the Alps. Auer, I., Böhm, R., Jurkovi\'c, A., Orlik, A., Potzmann, R., Schöner, W., Ungersböck, M., Brunetti, M., Nanni, T., Maugeri, M., Briffa, K., Jones, P., Efthymiadis, D., Mestre, O., Moisselin, J. M., Begert, M., Brazdil, R., Bochnicek, O., Cegnar, T., Gaji\'c-$\check\rm C$apka, M., Zaninovi\'c, K., Majstorovi\'c, $\check\rm Z$., Szalai, S., Szentimery, T., and Mercalli, L.: A new instrumental precipitation dataset for the Greater Alpine Region for the period 1800–2002, Int. J. Climatol., 25(2), 139–166, 2005. Barnston, G. A. and Livezey, R. E.: Classification, seasonality and persistence of low-frequency atmospheric circulation patterns, Mon. Weather. Rev., 115, 1083–1126, 1987. Bartolini, E.: Interannual variability of winter Alpine precipitation: relations with the North Atlantic Oscillation (in Italian), unpublished Master Thesis, Politecnico di Torino, Italy, 2007. Beniston, M., Diaz, H. F., and Bradley, R. S.: Climatic Change at high elevation site: an overview, Climatic Change, 36, 233–251, 1997. Beniston, M. and Jungo, P.: Shift in the distribution of pressure, temperature and moisture and changes in the typical weather patterns in the Alpine Regions in response to the behaviour of the North Atlantic Oscillation, Theor. Appl. Climatol., 71, 29–42, 2002. Chac$\acute\rm o$n, R. E. and Fernandez, W.: Temporal and spatial rainfall variability in the mountainous region of the reventazÛn river basin, Costa Rica, Int. J. Climatol., 5, 175–188, 1985. Haylock, M. R. and Goodess, C. M.: Interannual variability of European extreme winter rainfall and links with mean large-scale circulation, Int. J. Climatol., 24, 759–776, 2004. Helsel, D. R. and Hirsch, R. M.(eds): Statistical methods in water resources, Elsevier, Amsterdam, 1992. Hurrell, J. W.: Decadal trends in the North Atlantic Oscillation and relationship to regional temperature and precipitation, Science, 269, 676–679, 1995. Hurrell J. W. and Van Loon, H.: Decadal variation in climate associated with the North Atlantic Oscillation, Climatic Change, 36, 301–326, 1997. Jones, P. D., Jãnsson, T., and Wheeler, D.: Extension to the North Atlantic Oscillation using early instrumental pressure observations from Gibraltar and South-West Iceland, Int. J. Climatol., 17, 1433–1450, 1997. Lamb, P. J. and Peppler, R. A.: West Africa, edited by: Glantz, M. H., Katz, R. W., and Nicholls, N., in: Teleconnections linking the worldwide anomalies, Cambridge University Press, Cambridge, UK, 121–189, 1991. Mc Kee, T. B., Doesken, N. J., and Kleist, J.: The relationship of drought frequency and duration to time scale, Eighth Conference on Applied Climatology, Anaheim, California, USA, 17–22 January 1993. Mitchell, T. D., Carter, T. R., Jones, P. D., Hulme, M., and New, M.: A comprehensive set of high-resolution grids of monthly climate for Europe and the globe: the observed record (1901–2000) and 16 scenarios (2001–2100), Working Paper 55, Tyndall Centre for Climate Change Research, Norwich, UK, 2003. New, M. G., Hulme, M., and Jones, P. D.: Representing twentieth-century space-time climate variability. Part I: Development of a 1961-90 mean monthly terrestrial climatology, J. Climate, 12, 829–856, 1999. New, M. G., Hulme, M., and Jones, P. D.: Representing twentieth-century space-time climate variability. Part II: Development of a 1901-96 monthly terrestrial climate fields, J. Climate, 13, 2217–2238, 2000. Quadrelli, R., Lazzeri, M., Cacciamani, C., and Tibaldi, S.: Observed winter alpine precipitation variability and links with large-scale circulation pattern, Climate Res., 17, 275–284, 2001. Schmidli, J., Frei C., and Sch$\ddot\rm a$r, C.: Reconstruction of mesoscale precipitation fields from sparse observations in complex terrain, J. Climate, 14, 3289–3306, 2001. Schmidli, J., Schmutz, C., Frei, C., Wanner, H., and Sch$\ddota$r, C.: Mesoscale precipitation variability in the region of the European Alps during the 20th century, Int. J. Climatol., 22, 1049–1074, 2002. Thompson, D. W. J. and Wallace, J. M.: The Arctic Oscillation signature in the wintertime geopotential heigh and temperature fields, Geophys. Res. Lett., 29(9), 1297–1300, 1998. Thompson, D. W. J. and Wallace, J. M.: Annular modes in the extratropical circulation. Part I and II , J. Climate, 13, 1000–1036, 2000. Thompson, D. W. J. and Wallace, J.M.: Regional climate impacts of the Northern Hemisphere Annular Mode, Science, 293, 85–89, 2001.