24 Apr 2012:
European Satellite Provides Precise Data On Arctic Sea Ice Thickness
The European Space Agency’s (ESA) CryoSat satellite is now providing highly accurate data on the thickness and volume of Arctic Ocean ice. Using a high-resolution synthetic aperture radar that sends down pulses of microwave energy, the satellite can measure the difference between the top of the ice and water in the cracks, or leads, that separate the floes. By measuring the height of the ice above water, which usually represents only one-eighth of total ice thickness, the satellite can provide data on ice thickness to within 10 to 20 centimeters, or 4 to 8 inches. The CryoSat satellite was launched in 2010, and since then scientists have been validating the measurements against other data from plane-based instruments and direct, on-ice measurements. The data “are very reliable and the measurements we have match reality — we now have a very powerful tool to monitor the changes taking place at the poles,” said Volker Liebig, the ESA’s director of Earth Observation. Other satellites can accurately measure sea ice extent, but the ice thickness measurements provided by CryoSat offer a more complete view of rapidly melting Arctic sea ice.
Photographer Robert Wintner documents the exquisite beauty and biodiversity of Cuba’s coral reefs, which are largely intact thanks to stifled coastal development in the communist nation. View the gallery.
The Warriors of Qiugang, a Yale Environment 360 video, chronicles a Chinese village’s fight against a polluting chemical plant. It was nominated for a 2011 Academy Award for Best Documentary Short.
Watch the video.