Enhanced Cloud algorithm from collocated CALIPSO, CloudSat and MODIS global boundary layer lapse rate studies

Coincident profile information from CALIPSO's lidar and CloudSat's radar offers a unique opportunity to map the vertical structure of clouds over the globe with accuracies never before realized. At Langley NASA, both CALIPSO and CloudSat are collocated with each MODIS 1-km pixel to create a new data set named C3M (Figure 1). A year (July 2006 – June 2007) of C3M data is used to derive global lapse rate maps, as an enhancement to NASA Langley's CERES Cloud Property Retrieval System (CCPRS) [1]. The lapse rates are derived for boundary layer clouds using the the cloud-top temperature from Aqua MODIS level 1 data, skin temperature over ocean and surface temperature over land from the GMAO GEOS-4, and cloud-top height from CALIPSO. The derived global lapse rate maps are used to process a month of CERES-MODIS data to calculate cloud top heights, which are compared with CALIPSO cloud top height. The comparisons shows good agreement between CERES-MODIS and CALIPSO.