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Use of VOS data in Climate Products. Elizabeth Kent and Scott Woodruff National Oceanography Centre, Southampton NOAA Earth System Research Laboratory. Use of VOS data beyond Numerical Weather Prediction. IPCC - global ocean temperature trends Satellite bias removal Satellite cal/val
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Use of VOS data in Climate Products Elizabeth Kent and Scott Woodruff National Oceanography Centre, Southampton NOAA Earth System Research Laboratory
Use of VOS data beyond Numerical Weather Prediction • IPCC - global ocean temperature trends • Satellite bias removal • Satellite cal/val • WCRP SURFA flux validation • Flux datasets • Merging with metadata and ODAS into ICOADS for reanalysis and other climate applications
Evolving ICOADS coverage by platform type: Jul 1980 / 2005(oceanographic data not yet blended after 1997) ship oceanog. drifting moored C-MAN
Recent developments (1) • Statement from JCOMM-II on importance of data overseen by SOT being collected according to the GCOS Climate Monitoring Principles • Ship security and callsign masking • Both these issues to be discussed elsewhere at SOT - remembering that the requirements are also critical for climate applications
Recent developments (2) • Generalreduction over recent years of quantity of data from VOS • Coupled with some increases in AWS data • > frequency & < independence • Need for user requirements and adequacy monitoring • Are the user requirement definitions adequate? • Adequacy monitoring required for VOS (ETMC)
Recent VOS data (GTS-only 1998-) + WMO Pub. 47 Declining VOS… Green: reports with metadata 2005-6 not plotted yet
Adequacy requirements • User requirements for VOS not always well defined • VOS observations harder to assess for adequacy than other types of observations (e.g. drifters, ARGO) • VOS are an important source of several GCOS Essential Climate Variables (e.g. SST, air temperature, humidity) • Lack of targets and assessments leads to lack of investment and planning • Met Office-funded ASMOS project
ASMOS: Assessment of the Marine Observing System • Assessments of uncertainty in monthly fields • Relation of uncertainty to simple metrics • Number of days sampled • Number of platforms • Reports with metadata • Sampling of diurnal cycle • A start - but more work needed
Recent developments (3) • The climate data stream: issues include • Increased reliance on GTS reports, is this OK? • Difference in data streams from different centres, missing obs., data being changed and not flagged • Move to TDCFs: implications for consistency with historical data and data quality • Need to quantify added value of delayed mode
Recommendations for SOT to Consider • SOT should consider adding its support to the request by JCOMM for a scientific review of user requirements for the VOSClim and VOS programs, spanning both real time and climate applications. • SOT should aim to deliver the requirement for ship identification information to be available for all observations in the climate archive to ensure that observational metadata available in delayed mode (such as WMO Publication No. 47) can be associated with individual ship reports. • SOT should call for additional support to be made available for the provision of VOS metadata, both in near real time and delayed mode. • SOT should call for a review of the provision of VOS reports both in real time and delayed mode and contribute to the Expert Team on Marine Climatology (ETMC) Task Team on Delayed Mode VOS (TT-DMVOS).