Cloud macro- and microphysical properties are necessary to understand the relationship between clouds and the radiation budget and the role of clouds in the hydrological cycle. Quantities such as phase, effective particle size, optical depth, and altitude, can be used to determine the amount of cloud water and to compute the cloud's interaction with shortwave and longwave radiation. Little is known about Arctic cloud properties. Typically, estimation of these properties is more difficult over the Arctic than most other areas because of the extreme variations in surface albedo and the frequent occurrence of inversions and near-isothermal lapse rates in the polar troposphere. The former and latter conditions strongly affect the detection and interpretation of clouds at visible and thermal wavelengths, respectively. Because of its remoteness, satellite remote sensing is the only option for widespread, continuous monitoring of polar clouds. During the First ISCCP Regional Experiment (FIRE) Arctic Cloud Experiment (ACE), data from the Advanced Very High Resolution Radiometer (AVHRR) were taken by the Sun-synchronous satellites, NOAA-12 and NOAA-14, and analyzed for cloud properties using two multispectral algorithms. The Visible Infrared Solar-Infrared Technique (VIST) uses the visible (channel 1), 3.75-µm (channel 3), and 10.8-µm (channel 4) radiances to derive cloud optical depth, particle size, phase, and cloud temperature. The Solar-Infrared Infrared Split-Window Technique uses 3.75-µm, 10.8-µm, and 11.9-µm (channel 5) data to derive the same quantities. Sounding data are used to convert cloud temperature to height. The VIST is most useful for daytime measurements of thick clouds and thin clouds over darker surfaces. Because of the high albedo of snow at 0.65-µm, thin clouds yield ambiguous results over the Arctic ice pack. The SIST is applicable only to thin clouds (optical depths < 6), but is not sensitive to high-albedo surfaces and can be used at all times of day. Both algorithms are applied to the AVHRR data which covers a domain including the SHEBA ice camp and the ARM site at Barrow, Alaska. Results are presented and compared to radar and lidar observations from the surface sites and to in situ aircraft measurements taken during FIRE ACE flights