Greenland’s ICECAPS

Our incomplete understanding of polar clouds is a major source of uncertainty in models of the polar climate. Filling that gap is the goal of the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit (ICECAPS) project, which has been probing atmospheric and cloud processes in the skies above Greenland since 2010. With major contributions from the University of Colorado, the University of Wisconsin, Washington State University, Vanderbilt University, and the University of Oklahoma, the year-round research effort is based at the highest point of the Greenland ice sheet, Summit Station, some 3.2 km (10 500 feet) above sea level. Employing a comprehensive suite of instruments, the collaboration documents the micro- and macrophysical properties of clouds and their effects on the region’s energy budget and hydrological cycle.

This photo from last summer captures science technician Marci Beitch releasing a balloon-borne radiosonde that measures temperature, humidity, pressure, and wind velocity as a function of altitude. From such data, researchers derive cloud-temperature profiles and the thermodynamic state of the troposphere. The extensive record of twice-daily soundings has yielded a unique look at the atmosphere’s variability on time scales from weeks to years. Together with data from the other instruments, the observations are being used to study atmospheric processes, calibrate satellite observations, and improve model simulations. (Photo by August Allen, Polar Field Services.)

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