The South American Land Data Assimilation System (SALDAS) 5-Yr Retrospective Atmospheric Forcing Datasets

Abstract The definition and derivation of a 5-yr, 0.125°, 3-hourly atmospheric forcing dataset that is appropriate for use in a Land Data Assimilation System operating across South America is described. Because surface observations are limited in this region, many of the variables were taken from the South American Regional Reanalysis; however, remotely sensed data were merged with surface observations to calculate the precipitation and downward shortwave radiation fields. The quality of this dataset was evaluated against the surface observations available. There are regional differences in the biases for all variables in the dataset, with volumetric biases in precipitation of the order 0–1 mm day−1 and RMSE of 5–15 mm day−1, biases in surface solar radiation of the order 10 W m−2 and RMSE of 20 W m−2, positive biases in temperature typically between 0 and 4 K depending on the region, and positive biases in specific humidity around 2–3 g kg−1 in tropical regions and negative biases around 1–2 g kg−1 farth...

[1]  C. Bohren,et al.  An introduction to atmospheric radiation , 1981 .

[2]  A. Ohmura,et al.  First global WCRP shortwave surface radiation budget dataset , 1995 .

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

[4]  R. Reynolds,et al.  The NCEP/NCAR 40-Year Reanalysis Project , 1996, Renewable Energy.

[5]  K. Bryan.  A Numerical Method for the Study of the Circulation of the World Ocean , 1997 .

[6]  W. J. Shuttleworth,et al.  Evaluating NCEP Eta Model–Derived Data against Observations , 1998 .

[7]  Randal D. Koster,et al.  A Simple Framework for Examining the Interannual Variability of Land Surface Moisture Fluxes , 1999 .

[8]  J. Shukla,et al.  Impact of Initial Soil Wetness on Seasonal Atmospheric Prediction , 1999 .

[9]  Maria Stella Chiacchio,et al.  The WCRP/GEWEX Surface Radiation Budget Project Release 2: An Assessment of Surface Fluxes at 1 Degree Resolution , 2000 .

[10]  D. Lettenmaier,et al.  A Long-Term Hydrologically Based Dataset of Land Surface Fluxes and States for the Conterminous United States* , 2002 .

[11]  J. Janowiak,et al.  Global Land Precipitation: A 50-yr Monthly Analysis Based on Gauge Observations , 2002 .

[12]  J. D. Tarpley,et al.  Real‐time and retrospective forcing in the North American Land Data Assimilation System (NLDAS) project , 2003 .

[13]  Aaron A. Berg,et al.  Realistic Initialization of Land Surface States: Impacts on Subseasonal Forecast Skill , 2004 .

[14]  J. D. Tarpley,et al.  The multi‐institution North American Land Data Assimilation System (NLDAS): Utilizing multiple GCIP products and partners in a continental distributed hydrological modeling system , 2004 .

[15]  Jeffrey P. Walker,et al.  THE GLOBAL LAND DATA ASSIMILATION SYSTEM , 2004 .

[16]  Marcus Jorge Bottino,et al.  A simplified physical model for assessing solar radiation over Brazil using GOES 8 visible imagery , 2004 .

[17]  Sin Chan Chou,et al.  Evaluation of Eta Model seasonal precipitation forecasts over South America , 2005 .

[18]  W. J. Shuttleworth,et al.  Evaluation of model‐derived and remotely sensed precipitation products for continental South America , 2006 .

[19]  W. J. Shuttleworth,et al.  Impact of different initial soil moisture fields on Eta model weather forecasts for South America , 2006 .

[20]  Y. Hong,et al.  The TRMM Multisatellite Precipitation Analysis (TMPA): Quasi-Global, Multiyear, Combined-Sensor Precipitation Estimates at Fine Scales , 2007 .

[21]  V. Kousky,et al.  Assessing objective techniques for gauge‐based analyses of global daily precipitation , 2008 .

[22]  David L. Toll,et al.  Statistical Evaluation of Combined Daily Gauge Observations and Rainfall Satellite Estimates over Continental South America , 2009 .