Disclaimer: This material is being kept online for historical purposes. Though accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers. Visit https://espo.nasa.gov for information about our current projects.


MLS and CALIOP Cloud Ice Measurements in the Upper Troposphere: A Constraint...

Wu, D., A. Lambert, W. G. Read, P. Eriksson, and J. Gong (2014), MLS and CALIOP Cloud Ice Measurements in the Upper Troposphere: A Constraint from Microwave on Cloud Microphysics, J. Appl. Meteor. Climat., 53, 157-165, doi:10.1175/JAMC-D-13-041.1.

This study examines the consistency and microphysics assumptions among satellite ice water content (IWC) retrievals in the upper troposphere with collocated A-Train radiances from Microwave Limb Sounder (MLS) and lidar backscatters from Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP). For the cases in which IWC values are small (,10 mg m23), the cloud ice retrievals are constrained by both MLS 240- and 640GHz radiances and CALIOP 532-nm backscatter b532. From the observed relationships between MLS cloudinduced radiance Tcir and the CALIOP backscatter integrated g 532 along the MLS line of sight, an empirical linear relation between cloud ice and the lidar backscatter is found: IWC/b532 5 0.58 6 0.11. This lidar cloud ice relation is required to satisfy the cloud ice emission signals simultaneously observed at microwave frequencies, in which ice permittivity is relatively well known. This empirical relationship also produces IWC values that agree well with the CALIOP, version 3.0, retrieval at values ,10 mg m23. Because the microphysics assumption is critical in satellite cloud ice retrievals, the agreement found in the IWC–b532 relationships increase fidelity of the assumptions used by the lidar and microwave techniques for upper-tropospheric clouds.

PDF of Publication: 
Download from publisher's website.