In-Situ Radiometric Measurements of the Radiation Environment in Arctic Mixed-Phase Clouds from a Tethered Balloon System

Shortwave radiometric measurements within arctic boundary layer clouds were made with an instrument deployed on a tethered balloon system during a May/June 2008 experimental campaign at the arctic research station located at 78.9 N in Ny Alesund, Norway. This tethered balloon system enabled in-situ measurement of the mean light intensity at 500 nm and 800 nm using a specially designed radiometer attached to the tether. The balloon system had the ability to profile clouds vertically from ground level to 1.6 km and also to loiter at a fixed altitude for extended time periods. These radiometric measurements coupled with meteorological data and cloud particle images collected by other instruments attached to the balloon provide a unique picture of the radiation field within mixed-phase clouds. Data from several different deployments, encompassing a variety of cloudy sky conditions, will be presented and discussed.