Infrared Cloud Imager Cloud Cover Time Series

The Infrared Cloud Imager (ICI) was deployed at Barrow, AK from 13 July 2012 through 22 July 2014. This imager uses a thermal infrared camera with a 110 degree (diagonal) field of view and 1.25 aspect ratio to image the overhead sky in the 8 to 14 micron band. By removing the clear-sky radiance from the image, the remaining residual radiance is used to identify and classify clouds. For this current data stream the images have been processed to provide cloud fraction (fractional coverage by clouds across the imager's field of view), and cloud optical depth (spatial average of OD across the field of view including both clouds and clear sky). Additional information breaks Cloud fraction down into three categories thick clouds (cloud optical depth estimate of 2 or greater), thin clouds (cloud optical depth estimate between 1 and 2), and very thin clouds (cloud optical depth estimate between 0.25 and 1).