Data from the Noah 2.7.1 land hydrology model in the Global Land Data Assimilation System (GLDAS). The GLDAS system is described in the article by Rodell et al (2004). The input data for our processing was downloaded from the Goddard Space Flight Center DISC.
The mapped data available here is integrated total water content, obtained from the GLDAS output by summing the layers:
- % 65:WEASD :Accum Snow : kg/m^2
- % 86:SoilMoist1 :Average layer 1 soil moisture : kg/m^2
- % 86:SoilMoist2 :Average layer 2 soil moisture : kg/m^2
- % 86:SoilMoist3 :Average layer 3 soil moisture : kg/m^2
- % 86:SoilMoist4 :Average layer 4 soil moisture : kg/m^2
- % 071 Canopint Total canopy water storage [kg/m^2]
The grids of total water content every 3 hours were averaged over nominal months. The time-averaged grid Jan-2003 to Dec-2007 was then subtracted from all the individual monthly grids. The data are available in ASCII format (one file per month), in NetCDF format (one file for the whole time period), and as GIF images and animations.
This total water content is directly comparable to what GRACE measures over land. However, users need to be aware that the GLDAS version used here does not include groundwater and separate surface water components (such as rivers and lakes). Deviations from GRACE Total Water Storage changes can thus be expected, in addition to any errors in the model or observations. Also, the Greenland ice sheet areas have been masked out, as GLDAS does currently not feauture a dynamic ice model, and simulated values over ice covered regions are therefore not realistic.
Acknowledegment and Citation
If you use these data, please cite:
Rodell M, P. R. Houser, U. Jambor, J. Gottschalck, K. Mitchell, C.-J. Meng, K. Arsenault, B. Cosgrove, J. Radakovich, M. Bosilovich, J. K. Entin, J. P. Walker, D. Lohmann, and D. Toll (2004) : The Global Land Data Assimilation System. Bulletin of the American Meteorological Society, vol 85 (3), pp 381-394.
Also, please acknowledge receiving the GLDAS data from "http://grace.jpl.nasa.gov", which used the "Goddard Earth Sciences Data and Information Services Center".