Development and Evaluation of a New Method for AMSU-A Cloud Detection over Land

Satellite data are the main source of information for operational assimilation systems, and Advanced Microwave Sounding Unit-A (AMSU-A) one types satellite that contribute most to reduction numerical forecast errors. However, AMSU-A over land lags behind ocean. In this respect, accuracy cloud detection is factors affecting data, especially window low-peaking channel (23–53.59 GHz 89 GHz) data. Strong surface emissivity high spatial temporal variability make it difficult distinguish between radiative contributions clouds atmosphere. Based on differences in response characteristics different channels clouds, five (channels 1–4 15) were selected develop a new index land. Case studies showed can detect convective clouds; additionally, by further matching MHS (Microwave Humidity Sounder) index, we effectively cloudy clear-sky observations. Batch test results also verified stability method. By referring MODIS (Moderate Resolution Imaging Spectroradiometer) product, POD (probability detection) fields view with method was nearly 84%. using remove bias standard deviation observation-minus-simulated brightness temperature (O?B) significantly reduced, O?B 2–4 being below 1.0 K 5 6 K.