The Cryosphere www.the-cryosphere.net 1994-0416 1994-0424 2 2 2008 10.5194/tc-2-159-2008 http://www.the-cryosphere.net/2/159/2008/ http://www.the-cryosphere.net/2/159/2008/tc-2-159-2008.html http://www.the-cryosphere.net/2/159/2008/tc-2-159-2008.pdf 159 166 2008-11-19 Diagnosing the extreme surface melt event over southwestern Greenland in 2007 M. Tedesco mtedesco@sci.ccny.cuny.edu M. Serreze X. Fettweis City College of New York, City University of New York, New York, NY, 10031, USA NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA University of Maryland, Baltimore County, Baltimore, MD, 21250, USA Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA Département de Géographie, Université de Liège, Belgium Analysis of passive microwave brightness temperatures from the space-borne Special Sensor Microwave Imager (SSM/I) documents a record surface snowmelt over high elevations (above 2000 m) of the Greenland ice sheet during summer of 2007. To interpret this record, results from the SSM/I are examined in conjunction with fields from the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis and output from a regional climate model. The record surface melt reflects unusually warm conditions, seen in positive summertime anomalies of surface air temperatures, downwelling longwave radiation, 1000–500 hPa atmospheric thickness, and the net surface energy flux, linked in turn to southerly airflow over the ice sheet. Low snow accumulation may have contributed to the record through promoting anomalously low surface albedo. Armstrong, R. L., Knowles, K. W., Brodzik, M. J., and Hardman, M. A.: updated current year. DMSP SSM/I Pathfinder Daily EASE-Grid Brightness Temperatures [1988–2007], Boulder, Colorado USA, National Snow and Ice Data Center, digital media, 1994. Abdalati, W. and Steffen, K.: Snowmelt on the Greenland Ice Sheet as derived from passive microwave satellite data, J. Climate, 10, 241–251, 1997. Box, J. E., Bromwich, D. H., and Bai, L.-S.: Greenland ice sheet surface mass balance for 1991–2000: application of Polar MM5 mesoscale model and in-situ data, J. Geophys. Res., 109(D16), D16105, doi:10.1029/2003JD004451, 2004. Comiso, C., Parkinson, C. L., Gerttsen, R., and Stock, L.: Accelerated decline in the Arctic sea ice cover, Geophys. Res. Lett., 35, L01703, doi:10.1029/2007GL031972, 2008. De Ridder, K. and Gallée, H.: Land surface-induced regional climate change in Southern Israel, J. Appl. Meteorol., 37, 1470–1485, 1998. Fettweis, X., Gallée, H., Lefebre, L., and van Ypersele, J.-P.: Greenland surface mass balance simulated by a regional climate model and comparison with satellite derived data in 1990–1991, Clim. Dynam., 24, 623–640, doi:10.1007/s00382-005-0010-y, 2005. Fettweis, X.: Reconstruction of the 1979–2006 Greenland ice sheet surface mass balance using the regional climate model MAR, The Cryosphere, 1, 21–40, 2007. Gallée, H. and Schayes, G.: Development of a three-dimensional meso-γ primitive equations model, Mon. Wea. Rev., 122, 671–685, 1994. Hanna, E., Huybrechts, P., Steffen, K., Cappelen, J., Huff, R., Shuman, C., Irvine-Fynn, T., Wise, S., and Griffiths, M.: Increased runoff from melt from the Greenland Ice Sheet: a response to global warming, J. Climate 21, 331–341, doi:10.1175/2007JCLI1964.1., 2008a. Hanna, E., Cappelen, J., Fettweis, X., Huybrechts, P., Luckman, A., and Ribergaard, M. H.: Hydrologic response of the Greenland Ice sheet: the role of oceanographic warming, Hydrological Processes, in press, 2008b. Kalnay, E., Kanamitsu, M., Kistler, R., Collins W., et al.: The NCEP/NCAR 40-year reanalysis project, Bull. Amer. Meteor. Soc., 77, 437–470, 1996. Lefebre, F., Gallée, H., van Ypersele, J., and Greuell, W.: Modeling of snow and ice melt at ETH Camp (West Greenland): A study of surface albedo, J. Geophys. Res., 108(D8), 4231, doi:10.1029/2001JD001160, 2003 Mote T. L.: Greenland surface melt trends 1973–2007: Evidence of a large increase in 2007, Geophys. Res. Lett., 34, L22507, doi:10.1029/2007GL031976, 2007. Mote, T. L. and Anderson, M. R.: Variations in snowpack melt on the Greenland ice sheet based on passive microwave measurements, J. Glaciol., 41, 51–60, 1995. Serreze, M. C., Holland, M. M., and Stroeve, J.: Perspectives on the Arctic's shrinking sea ice cover, Science, 315, 1533–1536, 2007. Steffen, K., Nghiem, S. V., Huff, R., and Neumann, G.: The melt anomaly of 2002 in the Greenland Ice Sheet from active and passive microwave satellite observations, Geophys. Res. Lett., 31, L20402, doi:10.1029/2004GL020444, 2004. % %Stroeve, J. C., Box, J., Gao, F., Liang, S., Nolin, A., and Schaaf C.: Accuracy assessment of the MODIS 16-albedo product for snow: Comparison with Greenland in situ measurements, Remote Sensing of the Environment, 94(1), 46–60, 2005. Stroeve, J., Serreze, M., Drobot, S., Gearheard, S., Holland, M., Maslanik, J., Meier, W., and Scambos, T.: Arctic sea ice plummets in 2007, EOS, Trans. Am. Geophys. Union, 89, 13–14, 2008. Tedesco M.: A new record in 2007 for melting in Greenland, EOS, Trans. Am. Geophys. Union, 88(39), doi:10.1029/2007EO390003, 2007a. Tedesco, M.: Snowmelt detection over the Greenland ice sheet from SSM/I brightness temperature daily variations, Geophys. Res. Lett., 34, L02504, doi:10.1029/2006GL028466, 2007b. Ulaby, F. and Stiles, W.: The active and passive microwave response to snow parameters, 2: water equivalent of dry snow, J Geophys Res, 85, 1045–1049, 1980. M. Van den Broeke, Smeets, P., Ettema, J., Van der Veen, C., Van de Wal, R., and Oerlemans, J.: Partitioning of melt energy and meltwater fluxes in the ablation zone of the west Greenland ice sheet, The Cryosphere Discuss., 2, 711–736, 2008. % %Zwally, J. H., Abdalati, W., Herring, T., Larson, K., Saba, J., and Steffen, K.: Surface Melt-Induced Acceleration of Greenland Ice-Sheet Flow, Science, 297, 218-222, 2002.