NASA satellite maps global distribution of cloud ice

Washington: A bread loaf-sized NASA satellite has produced the world's first map of the global distribution of atmospheric ice in the 883-Gigahertz band, an important frequency in the submillimeter wavelength for studying cloud ice and its effect on Earth's climate.

IceCube -- the small spacecraft that deployed from the International Space Station in May 2017 -- is capable of measuring critical atmospheric cloud ice properties at altitudes between five km-15 km, NASA said in a statement on Wednesday. NASA scientists pioneered the use of submillimeter wavelength bands, which fall between the microwave and infrared on the electromagnetic spectrum, to sense ice clouds.

However, until IceCube, these instruments had flown only aboard high-altitude research aircraft. This meant scientists could gather data only in areas over which the aircraft flew. "With IceCube, scientists now have a working submillimeter radiometer system in space at a commercial price," said Dong Wu, a scientist and IceCube principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

"More importantly, it provides a global view on Earth's cloud-ice distribution," Wu said. Sensing atmospheric cloud ice requires scientists to deploy instruments tuned to a broad range of frequency bands. However, it is particularly important to fly submillimeter sensors.

This wavelength fills a significant data gap in the middle and upper troposphere where ice clouds are often too opaque for infrared and visible sensors to penetrate. It also reveals data about the tiniest ice particles that cannot be detected clearly in other microwave bands.

IceCube's map is a first of its kind and bodes well for future space-based observations of global ice clouds using submillimeter-wave technology, said Wu.