Information Management Methodology for Profiling Float Observations

NOAA requires subsurface temperature and salinity data for both operational and research activities. Operationally, the data are used to initialize seasonal to interannual climate forecast models. Research efforts are directed at increased understanding of ocean dynamics and the role of the ocean in coupled air-sea processes in order to improve forecast skill. Historically, temperature profiles have been obtained primarily using expendable bathythermographs (XBT's) launched from merchant vessels. Information management methodology including data transmission, tracking and quality control have been developed and implemented for the XBT data. Autonomous profiling floats have demonstrated the capability to obtain temperature and salinity profiles over greater depths and with improved vertical resolution and accuracy than available from XBT's. The floats launched from reasearch and commercial vessels sink to a prescribed depth (typically 1000 to 1500m) where they are advected by the ambient currents for a fixed time interval (typically 10 to 15 days). Returning to the surface, they measure temperature and salinity. On the surface, the floats transmit the profile data. Locations are determined using a positioning service. The information management methodology developed for the XBT data are being modified for the float data. A data 'pipeline' will be established from float to end user (in NOAA's case, the National Centers for Environmental Prediction, NCEP). 'Taps' will be placed along the pipeline to ensure that data flow is continuous. When leaks are identified, the problems will be identified and corrected. The final tap will be at NCEP and will identify float data that are not assimilated by the models. Whether the data are erroneous or the assimilation methodology is faulty will be determined and suitable remedies applied. Quality control procedures developed for XBT's will be automated and applied to the float data to ensure that inspected profiles are available in a timely manner, 24 hours a day, 7 days a week. Evaluation of the global float array to satisfy operational and research objectives will be a continuous activity of the information management scheme. Finally, suitable mechanisms will be implemented to provide the float data and data products to the widest possible community.