METHOD FOR RETRIEVING CLOUD THERMODYNAMIC PHASE USING 6.7 MICRO CHANNEL

摘要

Provided a method for retrieving cloud thermodynamic phase using 6.7 micro channel capable of substituting 8.7mum band used in the conventional cloud thermodynamic phase analysis algorithm using MODIS 3 channel spectrum with 6.7mum band so as to improve ice cloud retrieval. The method includes the steps of judging a cloud pixel having 10.8mum brightness temperature(BT_ 10.8) of less than 238K, bright temperature difference between 10.8mum and 12.0mum (BT_10.8-12.0) of 4.5K or more or 6.7mum brightness temperature(BT_6.7) of less than 234K as the ice phase, judging remaining cloud pixel having 10.8mum brightness temperature(BT_10.8) of 238K or more and less than 268K, or 6.7mum brightness temperature(BT_6.7) of 234K or more and less than 250K as the mixture phase, and judging remaining cloud pixel having 10.8mum brightness temperature(BT_10.8) of 285K or more, or 6.7mum brightness temperature(BT_6.7) of 250K or more as the water phase. The method further includes the step of judging a cloud pixel which is not judged as the water phase as an un-identified phase.