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MSU Satellite Data Set Description

The MSU Satellite data set is a product of the NASA and the University of Alabama in Huntsville.  In contrast to the GHCN and Jones et al. temperature data sets that represent temperatures at about 2 meters above the earth's surface, the MSU data set represent the temperatures of a layer of the atmosphere that extends from the surface to approximately 8 kilometers (5 miles) above the surface.  The data are obtained from microwave sounding units (MSUs) on the National Oceanic and Atmospheric Administration's TIROS-N satellites, which relate the intensity or brightness of microwaves emitted by oxygen molecules in the atmosphere to temperature.

Spatial coverage of the MSU data set is nearly global, and data are available in a grid-box size of 2.5 of latitude by 2.5 of longitude, which represents the finest spatial scale of the four data sets available on our web site.  Temporal coverage, however, is limited, as the MSU data set has only been in existance since 1979.  The version of the MSU data set used here is D.

We utilize two data files in plotting MSU temperature trends. Data from which annual trends are plotted by specified latitude band or region (as on this page, are obtained from a file located at Data from which patrons may calculate trends using any combination of 2.5° x 2.5° latitude/longitude grid cells (as on this page, are obtained from

The data of each grid box of the original data base for which the center is located within the user-defined grid box is weighted based upon the cosine of its latitude.  The weighted values are then summed to create mean values for the period of interest through which a regression line is fit.

When referencing this data set, or any of its output as calculated on our web site, please cite as:

Christy, J.R., Spencer, R.W., and Braswell.  2000.  MSU Tropospheric Temperatures: Dataset Construction and Radiosonde Comparisons.  Journal of Atmospheric and Oceanic Research 17: 1153-1170.

To calculate trends by specified latitude band or region using the MSU data set, click here.

To calculate trends by patron-defined 2.5 of latitude by 2.5 of longitude grid cells xusing the MSU data set, click here.