Service Interruption

21 April 2006

NSIDC and One World Expedition Partner for Arctic Field Measurements

Arctic explorers Lonnie Dupre and Eric Larsen will collaborate with NSIDC scientists Walt Meier and Thomas Painter, as well as Thomas Grenfell and Stephen Warren at the University of Washington, to take scientific snow and ice measurements. Dupre and Larsen, founders of the One World Expedition, are undertaking the first-ever summer crossing to the North Pole as part of Greenpeace's Project Thin Ice.

Dupre and Larsen will measure sea ice freeboard, or the amount of ice above the water line. The will also measure snow depth on top of the sea ice, as well as collecting and preserving snow samples. Dupre and Larsen will place the snow samples in specially prepared freezer bags that will travel close to the outside of the sleds to prevent melting.

The sea ice and snow measurements will help scientists make satellite data more accurate by providing ground-truth data and helping account for the effects of snow atop sea ice, which can cause "noise" in the data. This will be particularly helpful for validating data from the NASA Ice, Cloud, and Land Elevation Satellite (ICESat). Data from ICESat figures prominently in the measuring and monitoring of sea ice thickness and the changes the ice undergoes throughout the year.

The snow samples will help scientists understand the presence and amount of pollution, dust, and other contaminants in Arctic snow, as well as the movement of atmospheric particles. These snow samples are normally extremely difficult and expensive to obtain because they entail long treks across a sampling line.

More information about the expedition may be found at Greenpeace's Project Thin Ice Web site at For inquiries about the One World Expedition, contact Carol Gregory at or +1.202.462.1177. To learn about the scientific measurements and equipment involved in the team's sampling, please contact Stephanie Renfrow at or +1.303.492.1497.

For more information concerning ICESat, please visit To learn about last fall's record sea ice minimum, read the NSIDC press release Sea Ice Decline Intensifies.