The Global database provides the external parameters fields for the parameterisation of lakes in atmospheric modelling. It combines depth information for the individual lakes from different sources with a map. For mapping, the raster map of ECOCLIMAP2 dataset for ecosystems was used. For some large lakes the bathymetry is included. Additionally, the software to project the lake-related information accurately onto an atmospheric model grid is provided.

The dataset for individual lakes contain information about freshwater lakes (LakeDepthDataSet201002_for_web.txt.gz) and about saline lakes (SalineDepthDataSet201002_for_web.txt.gz). By now, the dataset comprises ca. 13 000 freshwater lakes and 220 saline lakes. The list of data sources includes ca. 295 references; the references are located in the headers. For each individual lake, the following information is provided: geographical coordinates of a point on the water surface, the mean depth of the lake, its maximum depth, its surface area, the lake name and the name of the country where the lake is located.

The list of the lakes with the bathymetry included is located in (LargeLakesIncluded.txt).

The global gridded datasets (GlobalLake.tar.gz) contain the following information on the geographical grid with the resolution of 30 sec. of arc (approx. 1 km): 1) the mean lake depth values or the bathymetry, and 2) the flag to estimate reliability of the lake depth information in every pixel of the grid (= 0 - no inland water, = 1 - the lake was not recognized by the automating mapping software, = 2 - the lake depth value was missing in the dataset for individual lakes, = 3 - the real depth value was used, = 4 - a river; for flags 1 and 2 it was used the default depth value of 10 m, for flag 4 - of 3 m). Data are in binary form provided by metadata in files-descriptions in the text form. The lake depth field is discontinuous hence averaging of the lake depth values is incorrect. The software (ProjectLake.tar) may help to aggregate the lake depth data and to project the lake depth information onto the atmospheric model grid. Different atmospheric models use very different coordinate systems, map projections and have very different grids. So, we propose the FORTRAN90 routine which performs the aggregation of the lake depth information for the one grid box of the atmospheric model grid, approximated by a polygon in geographical coordinated. The input to the routine is the geographical coordinates of the polygon peaks. The output is the lake fraction for the grid box in question, the most probable depth of lakes in the grid box in question, and the most probable flag value for the grid box in question.

For more details, please see Kourzeneva, E., 2009: Global dataset for the parameterization of lakes in Numerical Weather Prediction and Climate modeling. ALADIN Newsletter, No 37, July-December, 2009, F. Bouttier and C. Fischer, Eds., Meteo-France, Toulouse, France, 46-53. Use this reference also for the citation.