The Cross-track scanning Infrared Sounder (CrIS) on the NPOESS will play a primary role in providing the global soundings required for numerical weather forecasting and other atmospheric variables needed for climate monitoring and prediction. Besides the principal temperature and moisture soundings needed for weather forecasting, CrIS will provide useful information on cloud top height and ice/water phase as well as the optical thickness and effective ice particle radius of thin cirrus clouds. Cirrus cloud property variability can have a dramatic impact on climate change. It is also important to note that CrIS can provide carbon monoxide and ozone Tropospheric column content information needed for air quality monitoring and prediction. Radiance emissions by the major greenhouse gases (i.e., H2O, CO2, O3, CH4, and CO) are also to be monitored by the CrIS.

This presentation provides a current assessment of the CrIS instrument performance and its science measurement capability. Example results from the NPOESS Aircraft Sounding Testbed Interferometer (NAST-I) are presented to demonstrate that CrIS should be able to satisfy the science measurement expectations cited above. Plans will be discussed for validating CrIS performance during its maiden flight aboard the NPOESS Preparatory Platform (NPP) satellite, to be launched in 2006.