Twin NASA Satellites to Measure Earth's Polar Energy Emissions

Twin NASA Satellites to Measure Earth's Polar Energy Emissions
by Clarence Oxford
Los Angeles CA (SPX) May 31, 2024
NASA has launched the first of two shoebox-size CubeSats to help scientists understand the behavior of clouds and water vapor at Earth's polar regions and their impact on climate. The first satellite of the Polar Radiant Energy in the Far-InfraRed Experiment (PREFIRE) mission was launched from New Zealand on May 25. The second CubeSat is scheduled to launch on June 1.

The PREFIRE mission will measure the heat emitted by Earth from its polar regions. This data aims to improve models that predict changes in Earth's ice, seas, and weather patterns due to global warming.

Earth absorbs significant solar energy in the tropics, which is then transported to the poles by weather and ocean currents. Polar environments, including ice, snow, and clouds, emit this heat into space as far-infrared radiation. The difference between heat absorption in the tropics and emission at the poles is a key factor in the planet's temperature regulation.

PREFIRE will be the first mission to systematically measure far-infrared emissions from the poles. This will help researchers understand the role of atmospheric water vapor and clouds in heat emission. Clouds and water vapor can trap far-infrared radiation, contributing to the greenhouse effect and global warming.

"It's critical that we get the effects of clouds right if we want to accurately model Earth's climate," said Tristan L'Ecuyer, a professor at the University of Wisconsin-Madison and PREFIRE's principal investigator.

Clouds and water vapor at Earth's poles act like windows: clear, dry days allow heat to escape, while cloudy, humid days trap heat. The type and altitude of clouds influence the amount of heat retained by the atmosphere. Low-altitude clouds tend to cool the atmosphere, while high-altitude clouds absorb heat, generating a warming effect. Mid-altitude clouds can have either effect based on their water-droplet and ice-particle content.

Studying clouds is challenging due to their constantly changing nature. Their behavior can alter quickly with weather changes, complicating the task of accurately capturing them in climate models. Inconsistencies in cloud representation in models can significantly impact climate predictions.

PREFIRE's thermal infrared spectrometer will measure far-infrared light wavelengths, detecting clouds invisible to other optical instruments. The instruments will distinguish between liquid droplets and ice particles by detecting particle sizes.

"PREFIRE will give us a new set of eyes on clouds," said Brian Kahn, an atmospheric scientist at NASA's Jet Propulsion Laboratory and a member of the PREFIRE science team. "We're not quite sure what we're going to see, and that's really exciting."