The Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data (HOAPS) set is a completely satellite based climatology of precipitation, turbulent heat fluxes and freshwater budget (evaporation minus precipitation) as well as related athmospheric state variables over the global ice free oceans.

All variables are derived from SSM/I passive microwave radiometers, except for the SST, which is taken from AVHRR measurements. The dataset includes multi-satellite averages, inter-sensor calibration, and an efficient sea ice detection procedure.

Changes in this version are a longer time series, now containing data from 1987 to 2005, a new neural network based precipitation algorithm, and inclusion of the RSMAS/NODC Pathfinder Version 5 SST fields. Additionally a new 85 GHz synthesis procedure has been implemented, making a continuous time series for all parameters for the whole time series possible.

This dataset contains 1 degree twice daily globally gridded multi-satellite composite products, providing high temporal resolution. Each grid-cell contains data from only one satellite pass, there is no average from two or more satellites. Early passes are overwritten by later passes. This method provides more spatial homogeneity than averaging all available data. The fields are stored for 0-12 and 12-24 UTC. Timesteps in the data files are at 0 UTC (0-12 UTC overpasses) and 12 UTC (12-24 UTC overpasses). Each grid-cell contains the average of data from the satellite that passed this gridbox closest to 12 and 24 UTC, respectively.

Other gridded data sets available are pentad (5-day) and monthly means on a global 0.5 deg. x 0.5 deg. grid.

For more information see http://www.hoaps.org/.