24 July 2006: The CALIPSO spacecraft, NASA’s newest satellite mission, collected its first data recently. CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations), seeks to reveal the secrets of clouds and aerosols, tiny particles suspended in the air, enabling scientists to study how they form, evolve and interact and how they affect our air quality, weather and climate.
CALIPSO’s first images were taken in early June. They highlight the results of a major lava dome collapse at the Soufriere Hills Volcano on the island of Montserrat in the Caribbean. The dome collapse on May 20 involved an explosion that sent ash clouds 55,000 feet into the sky.
“The ability to observe and track a volcanic plume high in the atmosphere from the eruption of Soufriere Hills illustrates the high sensitivity of the satellite’s instruments and the promise of discoveries to come,” said David Winker, CALIPSO Principal Investigator at NASA’s Langley Research Center, Hampton, Virginia.
On June 7 CALIPSO’s Lidar, a device similar to radar that emits pulsed laser light instead of microwaves, obtained a vertical profile of the aerosol remnants of the Montserrat volcanic activity over Indonesia. Upper air movement carried a sulfur dioxide plume from the Caribbean island more than 11,000 miles to South East Asia.
The three instruments aboard CALIPSO are aligned to view the same area and work together to provide improved information on the size of ice crystals and other properties of thin clouds. The primary instrument is a polarization Lidar that provides unique, high-resolution vertical profiles of aerosols and clouds using laser pulses. It can detect natural and human-produced aerosols and thin clouds that are invisible to radar, and sometimes even to the human eye.
The spacecraft’s wide-field camera is used to determine cloud uniformity and provide a broader view of the location viewed by the Lidar. The imaging infrared radiometer operates continuously, providing information on cirrus cloud particle size and infrared emissions activity. It looks at the top surface of a broad sweep of cloud area.