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Rand Corporation Mean Monthly Global Snow Depth

Summary

All available monthly snow depth climatologies were integrated by the Rand Corporation, in the early 1980s, into one global (excluding Africa and South America) digital data set gridded at 4° latitude x 5° longitude. The U.S. Army Corps of Engineers monthly climatologies were a primary data source. For data-sparse areas such as China, Greenland, the Arctic and Antarctica, special Rand methodologies were used: empirical evaluation of total precipitation, weather source regions, latitude, temperature, terrain and annual snow depth data. Monthly ice-pack limits from U.S. Navy Oceanographic Office were used to extend the zero snow accumulation line over the oceans. These mean monthly data can be used strictly as a climatological summary or for systematic comparison with simulations from any general circulation model (GCM), or for initiating GCM calculations. Data report copies are also available. The global grid is too coarse to pick up snow accumulation in Africa and South America, but no more than two grid points are involved in these areas.

Citing These Data

Rand Corporation. 1995. Rand Corporation's global monthly snow depth. Boulder, CO: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N57P8W9K

We kindly request that you cite the use of this data set in a publication using the following citation example. For more information, see our Use and Copyright Web page.

Overview Table

Category Description
Data format

The data and the FORTRAN routine are in ASCII text files. The scanned documentation is in Adobe PDF format.

Spatial coverage and resolution The data cover the entire globe gridded at 4° latitude x 5° longitude.
Temporal coverage and resolution These climatologies show the global snow depth as a set of compatible mean-monthly snow accumulations, as of the last day of each month.
Tools for accessing data Data and the FORTRAN routine can be viewed with a text editor. The Rand report can be viewed using Adobe Acrobat or another PDF reader.
File naming convention Data are in the file titled "rand.dat". Scanned documentation and data can be found in the file "Rand_N-2687-RC.pdf", and the FORTRAN routine for the extraction of the data can be found in the "read_rand.f" file.
File size The data file is approximately 180 KB. The scanned documentation file is 3.3 MB.
Parameter(s) Data represent mean monthly snow depth values measured in inches.
Metadata access View metadata
Data access Data are available via FTP.

Table of Contents

1. Contacts
2. Overview
3. Detailed Data Description
4. Data Acquisition and Processing
5. Data Access and Related Collections
6. References and Related Publications
7. Acknowledgements
8. Document Information

1. Contacts

Investigators

Charles Schultz
The Rand Corporation
1700 Main Street
Santa Monica, CA 90406, USA

L. D. Bregman
The Rand Corporation
1700 Main Street
Santa Monica, CA 90406, USA

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

2. Overview

Background

See A Rand Note: Global Annual Snow Accumulation by Months (PDF file, 3.3 MB).

An attempt was made to develop snow accumulation values over water areas that are completely or mainly covered with pack ice. For this purpose, the "zero" snow accumulation lines were taken to be the boundaries of areas of greater than 5/10 sea ice cover. All grid points that fell within these lines in a particular month were given snow-accumulation values.

The number "0" in the tabulations denotes either zero accumulation or missing data, whereas the number "1" represents a trace. All data represent conditions on the last day of the month.

Breaks in the isopleths on the Army maps that were available were filled in by consulting temperature and snow data from supplementary sources. The Army data were further expanded during the coldest months with mean monthly ice limits from the U.S. Navy Hydrographic Office.

Grid Description

A global grid of 4° latitude x 5° longitude was used.

Format

The data and the FORTRAN routine are in ASCII text files. The scanned documentation is in Adobe PDF format.

File and Directory Structure

The following files contain the global monthly snow accumulation data as well as some FORTRAN code for extraction of the data. Note: This code was developed on an SGI running IRIX 4.0.1 and is only intended as a template. It may require updates by the user for the appropriate operating system.

Sample Data Record

This example is for the month of January. The data for each month are divided into parts representing the northwest, southwest, northeast, and southeast quadrispheres.

GLOBAL SNOW DEPTHS (INCHES) - JANUARY
180W
175W
170W
165W
160W
155W
150W
145W
140W
135W
130W
125W
120W
115W
110W
105W
100W
95W
90N
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
5.7
86N
6.7
6.4
6.4
6.4
6.4
6.4
6.4
6.4
6.4
6.2
6.2
5.7
5.7
5.7
5.7
5.7
5.7
5.7
82N
10.0
9.2
8.5
8.2
7.8
7.8
7.1
7.1
7.1
7.0
7.0
6.0
5.7
5.7
5.0
5.0
5.0
5.0
78N
10.6
10.3
10.0
9.6
9.2
8.9
8.5
8.2
7.8
7.8
7.2
7.1
6.4
5.7
5.7
5.7
5.6
7.1
74N
7.8
8.5
7.8
8.2
8.2
8.2
7.2
7.8
7.5
7.3
7.1
5.7
10.0
5.0
5.7
7.1
13.0
10.6
70N
3.5
2.8
2.8
5.0
15.0
16.0
15.0
16.0
3.5
3.5
15.0
2.4
2.1
17.0
15.0
10.0
10.0
12.5

3. Data Access and Related Collections

Data Access

Data are available via FTP.

Software and Tools

Data and the FORTRAN routine can be viewed with a text editor. The Rand report can be viewed using Adobe Acrobat or another PDF reader.

Related NSIDC Data Collections

4. References and Related Publications

Schultz, C., and L. D. Bregman. 1998. Global Annual Snow Accumulation by Months. Rand Note N-2687-RC.

5. Acknowledgements

Publication of this data set is supported by funding from NOAA's National Environmental Satellite, Data, and Information Service and the National Geophysical Data Center.

6. Document Information

Document Authors

Original documentation was based on information provided by L. D. Bregman.

Document Creation Date

1995

Document Revision Date

L. E. Husted reformatted this documentation and added the scanned reference "Rand_N-2687-RC.pdf" in February 2006.

Document URL

http://nsidc.org/data/docs/noaa/g00788_rand_global_snow_depth/index.html