Arctic clouds in multiyear satellite data sets

Cloud amounts from the International Satellite Cloud Climatology Project (I SCCP) D-series data set and the TOVS Polar Pathfinder data set are compared to surface observations of cloud amount from the North Polar (NP) drifting station data set for the central Arctic. The results show that cloud obser vations in the ISCCP data set differ significantly from surface observation s and the annual cycle of cloudiness in the Arctic is reversed from what is observed from the surface. In contrast, cloud amounts provided by the TOVS Polar Pathfinder data set represent the annual cycle of cloudiness well. P ath-P cloud retrievals also correspond well with surface observations (NP) at timescales greater than 4 days.