DYCOMS-II Satellite: DMSP SSM/I Water Vapor Imagery (GIF) 1.0 General Information The DMSP SSM/I Water Vapor Imagery (GIF) is one of several satellite products collected as part of the Dynamics and Chemistry of Marine Stratocumulus Phase II: Entrainment Studies (DYCOMS-II) project field catalog operated by the University Corporation for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS; http://www.joss.ucar.edu/dycoms/catalog/). The images were produced by the National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory (ETL) from the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I). Images are available once per day. The products cover the period from 1 - 30 July 2001 and cover the region from about 45 S to 45 N and 0 to 180 W. The products were acquired from the NOAA/ETL (http://www.etl.noaa.gov/satres/pacs_images.html) All images are in GIF format. 2.0 Data Contact Scot Loehrer (loehrer@ucar.edu) 3.0 Product Information The SSM/I data are provided courtesy of NOAA/NESDIS. SSM/I retrieved rainfall, cloud liquid water, and integrated water vapor products are computed daily over the region from 45S to 45N and 180E to 0W at a spatial resolution of 0.25 x 0.25 degrees. Currently we are receiving data from three SSM/I instruments, including DMSP F11, F13, and F14, providing us with nearly complete global daily coverage. Schluessel water vapor algorithm Estimates of the total column integrated water vapor amount are estimated using information from the 22.235 GHz SSM/I channel (Schluessel and Emery 1990; Schulz et al 1993; Bauer and Schluessel 1993), which is centered on a weak water vapor line. Integrated water vapor is the simplest and most accurate product to retrieve from the SSM/I and is therefore very useful for quantitative comparisons with model results or other data sets. 4.0 Quality Control Procedures UCAR/JOSS conducted no quality checks on these data. 5.0 File Naming Convention The file names are structured as follows: dmsp.yyyymmdd.SSM-I_Water_Vapor.gif Where dmsp is the type of satellite used yyyy is the four digit year mm is the two digit month dd is the two digit day SSM-I_Water_Vapor is the name of the product 6.0 References Schluessel, P., and W. J. Emery, 1990: Atmospheric water vapour over oceans from SSM/I measurements, Int. J. of Remote Sensing, Vol 11, pp. 753. Schulz, J., P. Schluessel, and H. Grassl, 1993: Water vapour in the atmospheric boundary layer over oceans from SSM/I measurements, Int. J. Rem. Sens., Vol 14, pp. 2773. Bauer, P. and P. Schluessel, 1993: Rainfall, total water, ice water, and water vapor over sea from polarized microwave simulations and special sensor microwave/imager data, J. Geophys. Res., Vol 98, pp. 20,737.