The Diurnal Cycle of Oceanic Precipitation in Models and Satellite Observations

The diurnal cycle of precipitation over the oceans, while not as large as over land, is important for modeling and research considerations but is not well documented. Numerous studies have examined this topic but most have been limited either geographically or by the use of infrared satellite information that has tenuous relationships with precipitation. Some have documented the durnal cycle using TRMM data, but the sampling characteristics of that sensor make it quite difficult to sort out seaonally varying components of the diurnal cycle. We will present results based on the CMORPH precipitation analyses that provide estimates of rainfall at 0.25 degree, 1/2 hourly spatial and time scales. We will also compare the diurnal cycle of precipitation between the CMORPH analyses and the NCEP operational model precipitation forecasts.