NASA JAXA GPM: Earth-based measurements needed to calibrate newest weather satellite

After Atlanta was paralyzed by a rare snowstorm, many fingers were pointed assigning blame for the resulting traffic catastrophe, including at least one aimed at imprecise weather predictions.

"The governor of Georgia said that they thought the heavier snowfall was going to be south of the city," said Ana Barros, professor of civil and environmental engineering at Duke University.

"But there's a lot of uncertainty in those predictions because we don't really understand the fine details of complex storm systems. We don't know how to model these processes at high spatial resolutions."

Ana Barros

This summer, Barros and her colleagues will conduct the first field mission with a new satellite system intended to fill in those knowledge gaps.

On Feb. 27, NASA and Japan's national space agency (JAXA) launched the core satellite for their new Global Precipitation Measurement (GPM) mission from Japan's Tanegashima Space Center.

GPM is an international satellite mission designed to provide more detailed measurements of rain and snow over a wider range of the globe than previously possible.

Not only will the satellite have more precise instrumentation than its predecessors; its orbit will allow researchers to study rainfall at higher latitudes at higher spatial and temporal resolutions.

The data it collects will help unify measurements made by partner satellites and add to science's understanding of how weather works.

Before meteorologists can start plugging the new data in to their weather models, however, researchers have to make sure they can accurately interpret the GPM measurements.

The upcoming field mission, based in the mountains of western North Carolina and led by Duke engineers, will help achieve this by comparing satellite readings with those taken simultaneously from multiple aircraft and ground sensors.

Besides calibrating the new satellite, the campaign will help improve how precipitation processes are represented in forecast calculations.

It will also provide data and inform models used to address critical water management issues in mountainous regions.

"The campaign that we are running will obtain very high-resolution data of precipitation and the microphysics of storm systems in mountainous regions," said Barros.

"The end goal is to improve weather predictions and climate models."