Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data - HOAPS 4.0

The Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite data record (HOAPS) is a completely satellite based climatology of precipitation, evaporation and freshwater budget (evaporation minus precipitation) as well as of latent heat flux, total column water vapour, near surface specific humidity and near surface wind speed over the global ice free oceans. All variables are derived from recalibrated and intercalibrated measurements from SSM/I and SSMIS passive microwave radiometers, except for the SST, which is taken from AVHRR measurements. The data record includes multi-satellite averages and an efficient sea ice detection procedure. Main changes in this version are a prolonged time series, now containing data for the time period from July 1987 until December 2014, the utilisation of an updated SSM/I and SSMIS FCDR, the provision of uncertainty estimates for latent heat flux, evaporation, near surface specific humidity and near surface wind speed and the implementation of a 1D-Var retrieval scheme for the retrieval of total column water vapour and near surface wind speed. Other retrieval algorithms remain unchanged compared to HOAPS 3.2. All HOAPS products have global coverage, i.e., within ±180° longitude and ±80° latitude and are only defined over the ice-free ocean surface. The products are available as monthly averages and 6-hourly composites on a regular latitude/longitude grid with a spatial resolution of 0.5° x 0.5° degrees. Along with the data and the uncertainty estimates, a comprehensive documentation including user manual, algorithm descriptions, reprocessing layout and extensive validation studies, are provided.