Understanding Hydrometeorology Using Global Models

The land surface coupling, a crucial element of the climate system, is explored in the recent 40-yr European Centre for Medium–Range Forecasts (ECMWF) reanalysis (ERA-40) model. In seasonal forecasts for the Northern Hemisphere summer, initialized with idealized soil moisture fields, the ERA-40 model has a large evaporation–precipitation feedback over the continents, and the memory of initial soil moisture is longest at high northern latitudes. Thirty years of hourly data from the ERA-40 reanalysis are averaged over the Madeira, Red–Arkansas, and Athabasca River basins. Although the model fully resolves the diurnal cycle and has an interactive prognostic cloud field, the transitions in the boundary layer climate over land can be mapped with remarkable precision by the daily mean state and daily flux averages. The coupling to cloud processes plays an essential role in the surface and boundary layer equilibrium. Soil moisture, cloud base, cloud cover, radiation fields, and evaporative fraction are coupled q...

[1]  A. Betts,et al.  Evaluation of the ERA-40 Surface Water Budget and Surface Temperature for the Mackenzie River Basin , 2003 .

[2]  Miller,et al.  The Anomalous Rainfall over the United States during July 1993: Sensitivity to Land Surface Parameterization and Soil Moisture Anomalies , 1996 .

[3]  Pedro Viterbo,et al.  The land surface‐atmosphere interaction: A review based on observational and global modeling perspectives , 1996 .

[4]  A. Betts,et al.  Budget analysis of FIFE 1987 sonde data , 1994 .

[5]  Pedro Viterbo,et al.  An Improved Land Surface Parameterization Scheme in the ECMWF Model and Its Validation. , 1995 .

[6]  Relation between equilbrium evaporation and the saturation pressure budget , 1994 .

[7]  A. Betts,et al.  Coupling between CO2, water vapor, temperature, and radon and their fluxes in an idealized equilibrium boundary layer over land , 2004 .

[8]  Michael R. Raupach,et al.  Combination theory and equilibrium evaporation , 2001 .

[9]  D. Lüthi,et al.  The Soil-Precipitation Feedback: A Process Study with a Regional Climate Model , 1999 .

[10]  Alan K. Betts,et al.  Idealized Model for Equilibrium Boundary Layer over Land , 2000 .

[11]  Alan K. Betts,et al.  Comparison between the land surface response of the ECMWF model and the FIFE‐1987 data , 1993 .

[12]  M. Garstang,et al.  Surface diurnal cycle and boundary layer structure over Rondônia during the rainy season , 2002 .

[13]  Michael R. Raupach,et al.  Equilibrium Evaporation and the Convective Boundary Layer , 2000, Boundary-Layer Meteorology.

[14]  Alan K. Betts,et al.  The FIFE surface diurnal cycle climate , 1995 .

[15]  Michael G. Bosilovich,et al.  Intercomparison of water and energy budgets for five Mississippi subbasins between ECMWF reanalysis (ERA‐40) and NASA Data Assimilation Office fvGCM for 1990–1999 , 2003 .