Validation of satellite derived CONUS cloud top pressure using cloud physics lidar data from the ATReC field campaign

The primary objective of this study is to assess the accuracy of satellite derived estimates of cloud top pressure. These estimates are derived using single field of view hourly data from the Geostationary Operational Environmental Satellite (GOES-12) Imager and Sounder instruments. In addition, cloud top pressure is derived using data from the MODerate resolution Imaging Spectrometer (MODIS), located on the polar-orbiting Aqua platform. Cloud Physics Lidar (CPL) data taken during the Atlantic-THORPEX Regional Campaign (ATReC) are used as reference data set. Using airborne lidar data provides the advantage that the cloud top heights are measured rather than derived, as they are when ground based data are used. For comparison with the lidar data, satellite derived estimates of cloud top pressure are converted to cloud top height using aircraft dropsonde data where available, or ground-based radiosonde data.

Future space borne weather satellites will most likely contain hyperspectral instruments (GOES-R HES, GIFTS). In preparation for this next generation of instruments, some research has focused on what information may be attained using hyperspectral technology, and how current products may be improved using these data. This study includes an assessment of cloud top height using data from the University of Wisconsin Scanning High resolution Interferometer Sounder (SHIS), a hyperspectral sensor which also flew aboard the NASA ER-2 during ATReC. Since the SHIS and the CPL were co-located on the same aircraft, we expect their assessment of cloud top height will be in good agreement. However, differences in field of view, as well as differences in the actual quantities measured by the two instruments make this a useful and informative comparison, especially given the need to assess hyperspectral cloud products in preparation for future satellite missions.