Paper on a new, improved way to get temperature and humidity data from GPS satellites into forecast models published in Monthly Weather Review

Atmospheric temperature and moisture can be measured accurately using radio signals from any Global Navigation Satellite System (GNSS) like the familiar Global Positioning System (GPS). The process, called “radio occultation,” measures changes in radio signals between satellites as they pass through the atmosphere. When incorporated into computer weather models, these data improve forecasts. However, when the density of the atmosphere significantly changes with height, like when there are moist and dry places or warm and cool places near each other, putting these observations into computer weather models is difficult. These places are usually near the surface, and, as a result, most weather models do not use these low-level observations. This study introduces a new way to the use of these observations in weather forecasts.

Schematic showing how temperature and humidity observations from GPS satellites are made. The GPS and Low-Earth Orbit (LEO) satellites are moving at speed V. The way the radio signals from the GPS satellite bend as they go through the atmosphere to reach the LEO satellite tells what the temperature and moisture is at that point, called the Tangent point.

Important Conclusions:

A new way to incorporate these difficult-to-use observations into computer weather models was developed.
Incorporation of these observations into computer weather models will improve our observation, understanding, and forecasts of the planetary boundary layer and improve weather forecasts.

For more information, contact aoml.communications@noaa.gov. The study can be found at https://doi.org/10.1175/MWR-D-22-0073.1.