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

The following example shows how to cite the use of this data set in a publication. 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.

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.

Rand_N-2687-RC.pdf: Rand note (scanned) providing background information and data (3.3 MB)
rand.dat: Data file (179 KB)
read_rand.f: FORTRAN extraction routine (3 KB)

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

Nimbus-7 SMMR Derived Monthly Global Snow Cover and Snow Depth

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

Service Interruption

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