Publication: Agreement between observed rainfall trends and climate change simulations in the southwest of Europe
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Advisors (or tutors)
American Meteorological Society
The lowest spatial scale at which current climate models are considered to be skillful is on the order of 1000 km because of resolution and computer capabilities. The estimation of the regional changes caused by anthropogenic emissions of greenhouse gases and aerosols therefore is problematic. Here a statistical downscaling scheme is used to study the relationship between large-scale sea lever pressure and regional precipitation in southwestern Europe, both in observed data and in outputs from a general circulation model (GCM) forced with increasing levers of greenhouse gases and sulfate aerosols. The results indicate that the GCM does reproduce the main aspects of the large- to local-scale coupled variability. Furthermore, these large- to local-scale relationships remain stable in the scenario simulations. The GCM runs predict increases of advection of oceanic air masses to the Iberian Peninsula that will produce a slight decrease of precipitation amounts in the north coast and the opposite effect in the rest of the territory, with values that could reach 10 mm decade^-1 in the south. In the homogenized historical records, the obtained pattern of change is very similar. These results support estimations of future regional trends simulated by the GCM under future emission scenarios.
© 2000 American Meteorological Society. The authors thank the Hadley Centre for supplying the model data and two anonymous referees for their helpful comments. Funding was provided by the Comunidad de Madrid, Project CLI97- 0341-c0301, and the Ramón Areces Foundation.
Alexandersson, H., 1986: Homogeneity test applied to precipitation data. J. Climatol., 6, 661–675. Barnett, T. P., and R. W. Preisendorfer, 1987: Origins and levels of monthly and seasonal forecast skill for United States surface air temperatures determined by canonical correlation analysis. Mon. Wea. Rev., 115, 1825–1850. Bretherton, C. S., C. Smith, and J. M. Wallace, 1992: An intercomparison of methods to find coupled patterns in climate data. J. Climate, 5, 541–560. Corte Real, J., X. Zhang, and X. Wang, 1995: Downscaling GCM information to regional scales: A non-parametric multivariate regression approach. Climate Dyn., 11, 413–424. Cui, M., H. von Storch, and E. Zorita, 1995: Coastal sea level and the large-scale climate state: A downscaling exercise for the Japanese Islands. Tellus, 47A, 132–144. Giorgi, F., C. Shields Brodeur, and G. T. Bates, 1994: Regional climate change scenarios over the United States produced with a nested regional climate model. J. Climate, 7, 375–399. González Rouco, J. F., J. L. Jiménez, V. Quesada, and F. Valero, 2000: Quality control and homogeneity of precipitation data in the southwest of Europe. J. Climate, in press. Hanssen-Bauer, I., and E. J. Forland, 1994: Homogenizing long Norwegian precipitation series. J. Climate, 7, 1001–1013. Hegerl, G. C., H. von Storch, K. Hasselmann, B. D. Santer, U. Cubasch, and P. D. Jones, 1996: Detecting greenhouse-gas-induced climate change with an optimal fingerprint method. J. Climate, 9, 2281–2306. Heyen, H., E. Zorita, and H. von Storch, 1996: Statistical downscaling of monthly mean North Atlantic air-pressure to sea level anomalies in the Baltic Sea. Tellus, 48A, 312–323. IPCC, 1995: Climate Change 1994—Radiative Forcing of Climate Change and an Evaluation of the IPCC IS92 Emission Scenarios. J. T. Houghton et al., Eds, Cambridge University Press, 198 pp. ---, 1996: Climate Change 1995—The Science of Climate Change. J. T. Houghton et al., Eds., Cambridge University Press, 584 pp. Johns, T. C., R. E. Carnell, J. F. Crossley, J. M. Gregory, J. F. B. Mitchell, C. A. Senior, S. F. B. Tett, and R. A. Wood, 1997: The second Hadley Centre coupled ocean–atmosphere GCM: Model description, spin-up and validation. Climate Dyn., 13, 103–134. Jones, R. G., J. M. Murphy, and M. Noguer, 1995: Simulation of climate change over Europe using a nested regional-climate model. I: Assessment of control climate, including sensitivity to location of lateral boundaries. Quart. J. Roy. Meteor. Soc., 121, 1413–1449. Mitchell, J. F. B., T. C. Johns, J. M. Gregory, and S. F. B. Tett, 1994: Climate response to increasing levels of greenhouse gases and sulphate aerosols. Nature, 376, 501–504. Murphy, J. M., 1995: Transient response of the Hadley Centre coupled ocean–atmosphere model to increasing carbon dioxide. Part I: Control climate and flux adjustment. J. Climate, 8, 36–56. Noguer, M., 1994: Using statistical techniques to deduce local climate distributions: An application for model validation. Meteor. Appl., 1, 227–287. Trenberth, K. E., and D. A. Paolino Jr., 1980: The Northern Hemisphere sea level pressure dataset: Trends, errors and discontinuities. Mon. Wea. Rev., 108, 856–872. von Storch, H., E. Zorita, and U. Cubasch, 1993: Downscaling of global climate estimates to regional scales: An application to the Iberian rainfall in wintertime. J. Climate, 6, 1161–1171. Wilby, R. L., and T. M. L. Wigley, 1997: Downscaling general circulation model output: A review of methods and limitations. Prog. Phys. Geogr., 21, 530–548. Zorita, E., E. Kharin, and H. von Storch, 1992: The atmospheric circulation and the sea surface temperature in the North Atlantic area in winter: Their interaction and relevance for Iberian precipitation. J. Climate, 5, 1097–1108. ---, J. P. Hughes, D. P. Lettenmaier, and H. von Storch, 1995: Stochastic characterization of regional circulation patterns for climate model diagnosis and estimation of local precipitation. J. Climate, 8, 1023–1042.