Publications

Wang, T; Fetzer, EJ; Wong, S; Kahn, BH; Yue, Q (2016). Validation of MODIS cloud mask and multilayer flag using CloudSat-CALIPSO cloud profiles and a cross-reference of their cloud classifications. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 121(19), 11620-11635.

Abstract
Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 cloud observations (MYD06) at 1km are collocated with daytime CloudSat-Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) (C-C) cloud vertical structures (2B-CLDCLASS-LIDAR). For 2007-2010, over 267 million C-C cloud profiles are used to (1) validate MODIS cloud mask and cloud multilayer flag and (2) cross-reference between C-C cloud types and MODIS cloud regimes defined by joint histograms of cloud top pressure (CTP) and cloud optical depth (). Globally, of total observations, C-C reports 27.1% clear and 72.9% cloudy, whereas MODIS reports 30.0% confidently clear and 58.7% confidently cloudy, with the rest 7.1% as probably clear and 4.2% as probably cloudy. Agreement between MODIS and C-C is 77.8%, with 20.9% showing both clear and 56.9% showing both cloudy. The 9.1% of observations are clear in MODIS but cloudy in C-C, indicating clouds missed by MODIS; 1.8% of observations are cloudy in MODIS but clear in C-C, likely due to aerosol/dust or surface snow layers misidentified by MODIS. C-C reports 47.4/25.5% single-layer/multilayer clouds, while MODIS reports 26.7/14.0%. For C-C single-layer clouds, similar to 90% of tropical MODIS high (CTP<440hPa) and optically thin (<3.6) clouds are identified as cirrus and similar to 60% of high and optically thick (>23) clouds are recognized as deep convective in C-C. Approximately 70% of MODIS low-level (CTP>680hPa) clouds are classified as stratocumulus in C-C regardless of region and optical thickness. No systematic relationship exists between MODIS middle-level (680

DOI:
10.1002/2016JD025239

ISSN:
2169-897X