Simulation of climate change over Europe using a global variable resolution general circulation model

Abstract This study presents results from a downscaling simulation of the impact of a doubling of CO2 concentration. A multidecadal coupled simulation of a 1% per year increase of CO2 concentration with the Hadley Centre ocean-atmosphere model provides its sea-surface temperatures and deep soil climatological temperatures as a boundary condition to two 10-year integrations with a version of the ARPEGE-IFS atmosphere model. This global spectral model has a horizontal resolution varying between 60 km in the Mediterranean Sea and 700 km in the southern Pacific. The global impact as well as the regional impact over Europe in this time slice are examined and compared with results from other studies. Over Europe, our main focus, the model impact consists of a warming of about 2 °C, relatively uniform and with little seasonal dependence. There are precipitation increases of about 10% over the northern part in winter and spring, and 30% over the southern part in winter only. Precipitation decreases by 20% in the southern part in autumn. The day-to-day variability of the precipitation increases, except over the southern area in summer. No strong impact is found on the soil moisture. Budgets of physical fluxes are examined at the top of the atmosphere and at the land-atmosphere interface.

[1]  J. Louis A parametric model of vertical eddy fluxes in the atmosphere , 1979 .

[2]  Daniel Cariolle,et al.  Southern hemisphere medium-scale waves and total ozone disturbances in a spectral general circulation model , 1986 .

[3]  Philippe Courtier,et al.  A global numerical weather prediction model with variable resolution: Application to the shallow‐water equations , 1988 .

[4]  S. Planton,et al.  A Simple Parameterization of Land Surface Processes for Meteorological Models , 1989 .

[5]  F. Giorgi,et al.  A 2XCO2 climate change scenario over Europe generated using a limited area model nested in a general circulation model 2. Climate change scenario , 1992 .

[6]  B. Ritter,et al.  A comprehensive radiation scheme for numerical weather prediction models with potential applications in climate simulations , 1992 .

[7]  W. Gates AMIP: The Atmospheric Model Intercomparison Project. , 1992 .

[8]  D. Stephenson,et al.  GCM Response of Northern Winter Stationary Waves and Storm Tracks to Increasing Amounts of Carbon Dioxide , 1993 .

[9]  J. Mahfouf,et al.  Response of the Météo-France climate model to changes in CO2 and sea surface temperature , 1994 .

[10]  M. Déqué,et al.  High resolution climate simulation over Europe , 1995 .

[11]  J. Gregory,et al.  Simulation of daily variability of surface temperature and precipitation over europe in the current and 2 × Co2 climates using the UKMO climate model , 1995 .

[12]  J. M. Gregory,et al.  Climate response to increasing levels of greenhouse gases and sulphate aerosols , 1995, Nature.

[13]  E. Roeckner,et al.  Regional climate simulation with a high resolution GCM: surface radiative fluxes , 1995 .

[14]  J. Mahfouf,et al.  Sensitivity to prescribed changes in sea surface temperature and sea ice in doubled carbon dioxide experiments , 1995 .

[15]  Richard G. Jones,et al.  Simulation of climate change over europe using a nested regional‐climate model. I: Assessment of control climate, including sensitivity to location of lateral boundaries , 1995 .

[16]  D. Lüthi,et al.  Surrogate climate-change scenarios for regional climate models , 1996 .

[17]  John F. B. Mitchell,et al.  Global and regional variability in a coupled AOGCM , 1997 .

[18]  John F. B. Mitchell,et al.  The second Hadley Centre coupled ocean-atmosphere GCM: model description, spinup and validation , 1997 .

[19]  J. Murphy,et al.  Simulation of climate change over europe using a nested regional‐climate model. II: Comparison of driving and regional model responses to a doubling of carbon dioxide , 1997 .

[20]  G. Watts,et al.  Climate Change 1995 , 1998 .