A note on the occurrence of cloud in meteorologically sensitive areas and the implications for advanced infrared sounders

The geographical distribution and persistence of meteorologically sensitive areas (derived using adjoint forecast‐error tracking techniques) are investigated with respect to the occurrence of cloud. Using sensitivity patterns and cloud structures simulated from the ECMWF forecast model a high degree of correlation is found which, if realistic, could limit the ability of space‐based advanced infrared sounders to measure important meteorological features. The result underlines the need to develop techniques to use infrared sounder observations in the presence of cloud.