New Terrain Program

• Motivation

• Program Function

• Source Datasets

• Program Tar File

• How to Run It?

• Program Documentation

Motivation

The Version 3 Terrain program is based on Version 2 workstation version. In this version, the program supports six resolutions of global terrestrial datasets at 60, 30, 10, 5, and 2 minutes, and 30 seconds. All lower resolution datasets were created from the 30 second data wherever possible.

The Version 3 Terrain program also supports land-surface model option in MM5 by providing additional terrestrial data, such as soil category, deep soil temperature, and vegetation fraction.

Program Function

The Terrain job script can automatically acquire data from USGS's anonymous ftp. The data can also be downloaded prior to running the program. In this case, the directory where data resides needs to be specified.

The program can be run on both Cray and workstations.

The resolution of input data is selected by choosing appropriate value for namelist variable NTYPE.

For elevation data, two preprocessors are run in the ftp script (Data/ftp30s.csh) to acquire and reformat the new 30 sec data.

To use the vegetation dataset to create landuse, set namelist variable Vegtype = 1 for USGS data, and = 2 for regional SiB data, or = 0 for old 13-category landuse data.

The vegetation dataset is also used to create land-water mask and used in the program in place of EZFUDGE option (which makes use of NCAR Graphics' coastline information) if one chooses the USGS or SiB data option.

There are two types of vegetation datasets one can choose to generate landuse. The USGS data is nearly a global one (except Antarctica (south of 60 S), eastern Greenland (east of 40 W), and the east tip of Siberia (east of 180 E)), and has 24 landuse categories including urban. The category for water is 16. The SiB dataset is North American (60W - 180W, and 0N - 90N), and has 16 landuse categories but without urban. The water category is 15. The SiB dataset is the same one used in NCEP's Eta model.

Source Datasets

Global 30 Second Elevation Data

USGS provides the 30 sec terrain data from their anonymous ftp site: ftp://edcftp.cr.usgs.gov/pub/data/gtopo30/global. The dataset is archived in a total of 33 files. A tile map can be found from the same site: tiles.gif.

Global 30 Second Vegetation Data

Starting from V3-5 release, we began to use the USGS Version 2 global 30 sec vegetation data. Coarser resolution datasets at 1 degree, 30', 10', 5' and 2' were generated from the 30 sec dataset. We provide these datasets on anonymous ftp site:

ftp://ftp.ucar.edu/mesouser/MM5V3/TERRAIN_DATA

For more information on the dataset, pleaes visit the USGS site.

Global 5 minute United-Nation FAO Soil Category Data

Since V3.5, the soil category data outside continental US has been updated to the 5-minute UN-FAO data. In the continental US, the soil category data are 30-second resolution, and from STATSGO.

Program Tar File

On NCAR's anonymous ftp:

ftp://ftp.ucar.edu/mesouser/MM5V3/TERRAIN.TAR.gz

On NCAR's MSS:

/MESOUSER/MM5V3/TERRAIN.TAR.gz

How to Run It?

1. Obtain the source code tar file from NCAR's ftp site.

2. Read the README file inside the tar file;

3. Type make terrain.deck to obtain the deck for your computer system;

4. Edit terrain.deck to set appropriate script and namelist options;

5. Type terrain.deck to compile and run the job.

Program Documentation

Please read the README file and Chapter 4 of the Tutorial Notes.

For more help on running the Terrain program, please see our online tutorial.