Earth Exploration-Satellite Service

EESS (passive) spectrum in the range between 71 and 238 GHz is used operationally for several vital measurements of Earth and its atmosphere for weather and climate applications. Global water vapor profiles are essential to the numerical weather prediction of rainfall and drought and help constrain such predictions in general.2 Water vapor is the primary mechanism for energy storage and its movement within the atmosphere as it drives extreme weather events. Combined microwave and infrared spectral data can yield what is nearly all-weather global observations, even in most cloudy conditions, of water vapor and air temperature profiles.3 The critical importance of the oxygen and water vapor lines at 115-122 and 176-190 GHz cannot be over emphasized: due to the unique molecular properties of oxygen and water vapor, atmospheric temperature and humidity in particular cannot be measured in bands other than those currently allocated. A list of additional scientific applications is given in Table 2.4 and Table 2.5 gives a list of corresponding applicable frequencies. Given the importance of weather forecasting and climate monitoring to the public, it is important that we protect this region of the spectrum for continued successful EESS use.

TABLE 2.5 EESS Uses of Spectrum from 71 to 238 GHz


Use/Measurement/Target Significance Frequencies (GHz)

Atmospheric humidity and temperature profiles Used operationally in numerical weather prediction, forecasting of severe storms, and monitoring climate 115-122, 176-190
 
Cloud ice content Forecasting of severe storms, and monitoring climate 8585-92, 150-160
 
Precipitation Planning operations and monitoring climate 8585-92
 
Land surface type Monitoring climate 8585-92
 
Trace gases Mapping of key atmospheric constituents (HCN, NHO3, N2O, ClO, CO, O3) tied to carbon cycle, global climate, ozone depletion, pollution, atmospheric transport 177.26, 181.59, 200.98, 204.35, 206.13, 230.54, 233.95, 235.71
 
Sea ice extent and concentration Monitoring climate 8-92

SOURCE: Adapted from Tables 2.1 and 2.2 found in National Research Council, Spectrum Management for Science in the 21st Century, The National Academies Press, Washington, D.C., 2010, pp. 137-138.

_________________

2 National Research Council, Spectrum Management for Science in the 21st Century, The National Academies Press, Washington, D.C., 2010, pp. 29-30.

3 Ibid.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement