1. The HOAPS-3 climatology
Stephan Bakan1, Axel Andersson1, Karsten Fennig3, Hartmut Grassl2, Christian Klepp2, Jörg Schulz4
1 Max Planck Institute for Meteorology, Hamburg 2 University of Hamburg, 3 German Weather Service (DWD), Offenbach, 4EUMETSAT, Darmstadt, all Germany
HOAPS - Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data
HOAPS is a climatology of freshwater flux over the global ocean derived from satellite data:
data availability:
precipitation, evaporation and related surface and atmospheric parameters
radiometers on board polar orbiting satellites: - SSM/I (passive microwave) - AVHRR (infrared, SST only)
state of the art parameter retrieval procedures
homogeneous time series: Multi satellite averages, containing all SSM/I operating at the same time, including inter-sensor calibration
Scan-based, pixel-level dataset (HOAPS-S)
gridded (HOAPS-G, HOAPS-C) datasets , resolution 0.5°, pentad and monthly means, daily composites
data accessible under:
References:
Andersson, A., C. Klepp, K. Fennig, S. Bakan, H. Graßl, and J. Schulz, 2010: The Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data – HOAPS-3. Earth Syst. Sci. Data, 1, 1-20, doi: /essdd
Andersson, A., C. Klepp, K. Fennig, S. Bakan, H. Graßl, and J. Schulz, 2010: Evaluation of HOAPS-3 ocean surface freshwater flux components. J. Appl. Meteor. Climatol., doi: /2010JAMC2341.1, in print
Statistical approach on brightness temperature (TB) basis:
calibration reference: DMSP F-11
10-day means of TBs averaged on a global 1°x1° grid, rain-free pixels only
match-ups for each channel and satellite with F-11 for one overlapping year
histogram-equalization of match-ups
linear regression for TB calibration coefficients of each channel and satellite
SSM/I intercalibration:
Data processing chain:
HOAPS-3 parameters and algorithms:
Water flux parameters:
Precipitation (P):
neural net with training data from radiative transfer calculations (ECMWF, P. Bauer)
Evaporation (E):
Bulk formula: E = (ρa/ρw) CE U (qs – qa)
Wind speed (U) (neural net)
Near surface specific humidity (qa) (Bentamy et al., 2003)
Sea surface saturation specific humidity (qs) (SST, Magnus formula)
Latent heat transfer coefficient (CE) (COARE; Fairall et. al., 1996/2003)
Freshwater Flux: E-P
Climatological mean global fields (left) and annual cycle of zonal mean (right) of precipitation, evaporation and freshwater flux (E-P)
HOAPS-3 is a well developed satellite climatology of water cycle components over the ice free global ocean, showing all the known global climatological features and regional details
HOAPS 3 is publicly available from
In near future, some of the core HOAPS products will be routinely provided by the Eumetsat Climate Monitoring Satellite Application Facility (CM-SAF, at the German Weather Service (DWD)
Conclusions: