The Shelf Seas of the Arctic are known for their large sea-ice production. This paper presents a comprehensive view of the Kara Sea sea-ice cover from high-resolution numerical modeling and space-borne microwave radiometry. As given by the latter the average polynya area in the Kara Sea takes a value of 21.2 × 103 km2 ± 9.1 × 103 km2 for winters (Jan.-Apr.) 1996/97 to 2000/01, being as high as 32.0 × 103 km2 in 1999/2000 and below 12 × 103 km2 in 1998/99. Day-to-day variations of the Kara Sea polynya area can be as high as 50 × 103 km2. For the seasons 1996/97 to 2000/01 the modeled cumulative winter ice-volume flux out of the Kara Sea varied between 100 km3a-1 and 350 km3a-1. Modeled high (low) ice export coincides with a high (low) average and cumulative polynya area, and with a low (high) sea-ice compactness in the Kara Sea from remote sensing data, and with a high (low) sea-ice drift speed across its northern boundary derived from independent model data for the winters 1996/97 to 2000/01. Copyright 2005 by the American Geophysical Union.