Posted inNews

Geostationary sounder is a key ingredient of near-term forecasts

Harris AVHRR
These are temperature and moisture profiles drawn from the Harris-built Cross track Infrared Sounder on the Joint Polar Satellite System. Credit: Harris

SAN FRANCISCO – The National Oceanic and Atmospheric Administration’s next generation of geostationary weather satellites will significantly improve weather forecasting thanks to the addition of a hyperspectral infrared sounder.

That was the consensus at the American Meteorological Society annual meeting in Denver, where scientists, program managers and industry executives discussed the benefits of adding data from a Geostationary Extended Orbits (GeoXO) Sounders to the other observations that feed weather models.

“With our hyperspectral infrared sounder, we’ll start collecting very frequent temperature and humidity data to help improve numerical weather prediction, nowcasting and localized forecasts,” said Joel McCorkel, GeoXO project scientist. (Nowcasting describes weather conditions in the next few hours like hail, high winds and flash floods.)

NOAA flies two sounders in low-Earth orbit, the Advanced Technology Microwave Sounder, built by Northrop Grumman, and the L3Harris Cross Track Infrared Sounder, in the Joint Polar Satellite System constellation. Previous generations of NOAA geostationary weather satellites also carried sounders, but the instrument was dropped from plans for the Geostationary Operational Environmental Satellite-R series due to cost and technical concerns.

Without a sounder in the GOES-R constellations, the National Weather Service relies on data from weather balloon radiosondes and instruments in polar orbit to feed weather models.

Radiosondes provide information twice a day, but most of the readings are taken over land rather than oceans, said Timothy Schmit, a research scientist in the NOAA National Environmental Satellite Data and Information Service Advanced Satellite Products Branch. Polar orbiters offer global coverage but don’t help forecasters monitor rapidly evolving weather conditions as well as a geostationary satellites, he added.

Simulations to evaluate the benefits of the new GeoXO Sounder, known as GXS, show significant improvement in forecasting the path of storms as well as their intensity, Schmit said.

“Geostationary sounders help predicted what is about to happen,” Rob Mitrevski, L3Harris Spectral Solutions vice president and general manager, told SpaceNews. As a result communities in the path of a natural disaster have more time for evacuation or other activities to mitigate the impact, he added.

GeoXO is NOAA’s largest procurement in history. The $19.6 billion GeoXO budget approved in December covers six satellites, operations and support extending from 2022 to 2052.

NOAA plans to position satellites over the East and West Coasts, like the current GOES-R constellation, plus a third central satellite. The sounder and an atmospheric composition instrument are destined for the central satellite.

NOAA plans to launch its first GeoXO satellite in 2032. The sounder satellite is slated to follow in 2035.

In addition to the sounder, NOAA’s GeoXO constellation will include instruments to provide visual and infrared imagery for weather and climate applications, observations of lightning, atmospheric composition and ocean color.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...