Multiangle observations of Arctic clouds from FIRE ACE: June 3, 1998, case study

In May and June of 1998, the Airborne Multiangle Imaging SpectroRadiometer (AirMISR) participated in the FIRE Arctic Cloud Experiment (ACE). AirMISR is an airborne instrument for obtaining multiangle imagery similar to that of the satellite-borne MISR instrument. This paper presents a detailed analysis of the data collected on June 3, 1998. In particular, AirMISR radiance measurements are compared with measurements made by two other instruments, the Cloud Absorption Radiometer (CAR) and the MODIS airborne simulator (MAS), as well as to plane-parallel radiative transfer simulations. It is found that the AirMISR radiance measurements and albedo estimates compare favorably both with the other instruments and with the radiative transfer simulations. In addition to radiance and albedo, the multiangle AirMISR data can be used to obtain estimates of cloud top height using stereo-imaging techniques. Comparison of AirMISR retrieved cloud top height shows excellent agreement with the measurements from the airborne Cloud Lidar System (CLS) and ground-based millimeter-wave cloud radar.