Ancillary Data Sets Used for IMAPP Product Generation ----------------------------------------------------- Updated 23 March 2007 The entire set of leading edge and archived ancillary data sets used by the IMAPP Level 2 software is available from this ftp site: ftp://ftp.ssec.wisc.edu/pub/eosdb/ancillary ------------------------------------------------------------------------------- Name: Total Ozone Analysis using SBUV/2 and TOVS (TOAST) Note: The file name was updated on 30 November 2006 to exclude the 16 in the file name. The data will still be distributed from our web site with the 16 included until further notice. We now pull the files usign wget from this site: http://www.osdpd.noaa.gov/PSB/OZONE/TOAST/data/GRIB/toast_grb.html Example File Name: TOAST16_050615.GRB Used by IMAPP Product: MODIS Aerosol (MOD04) File Type: Binary GRIB File Source: NOAA/NESDIS Please see more detailed information about the product at this web site: http://www.osdpd.noaa.gov/PSB/OZONE/TOAST/ File Content Description: Daily TOVS and SBUV/2 Total Ozone from NESDIS File Structure Description: Each file contains retrieved Total Ozone in Dobsons on a 1 degree global grid. The file is in GRIB format. Record/Line Format: Single GRIB record containing ozone on 360x181 1 degree global grid. Archived Data: A TOAST archive has been created and can be accessed through this public web site: ftp://www.orbit.nesdis.noaa.gov/pub/smcd/spb/ozone/toast/data/TOAST/GRIB ------------------------------------------------------------------------------- Name: The Near Real-Time SSM/I EASE-Grid Daily Global Ice Concentration and Snow Extent (NISE) Example File Name: NISE_SSMIF13_20020430.HDFEOS Used by IMAPP Products: MODIS Cloud Mask (MOD35) File Structure Description: Each file contains NISE snow/ice extent on 721x721 northern and southern hemisphere azimuthal grids. The file is in HDF-EOS format. Record/Line Format: Snow/ice extent for the northern and southern hemispheres stored in separate HDF-EOS Grid objects. Product Description: The Near Real-Time SSM/I EASE-Grid Daily Global Ice Concentration and Snow Extent (NISE) product is generated by the National Snow and Ice Data Center (http://nsidc.org). This data set was originally designed to provide NASA EOS researchers with near real-time, daily, global snow extent and sea ice concentration data. The MODIS Instrument Team uses the NISE data as input to their products. Data access is unrestricted but users are strongly encouraged to register with NSIDC as users of the data. Registered users automatically receive notification of changes in the product-generation algorithm and of modifications in data manipulation and formatting. Registered users automatically receive E-mail notification of any data production problems. NSIDC requests that prospective data users explain how the data will be used and agree to contribute comments regarding the usefulness, relevance, and accuracy of the data. Such feedback is essential to ensure ongoing product improvement. A link to register for the data and read more about the product can be found at: http://nsidc.org/data/nise1.html ------------------------------------------------------------------------------ Name: Daily SSMI sea ice concentration from the National Centers for Environmental Predition (NCEP) Example File Name: eng.020430 Used by IMAPP Products: MODIS Cloud Mask (MOD35) File Type: Binary GRIB File Structure Description: Each file contains SSMI sea ice concentration on a 0.5 degree global grid. The file is in GRIB format. Record/Line Format: Single GRIB record containing ice concentration on 720x360 0.5 degree global grid. Archived Data: The official Sea Ice distribution site is: ftp://polar.ncep.noaa.gov/pub/cdas ------------------------------------------------------------------------------ Name: 6 hourly Global Data Assimilation System T126 resolution analysis from NCEP. Example File Name: gdas1.PGrbF00.020430.00z Used by IMAPP Products: MODIS Cloud Top Properties, Cloud Mask and Atmospheric Profiles (MOD06CT, MOD35, MOD07) AIRS Clear Sky Retrievals AMSU Liquied Water Path (LWP) File Type: Binary GRIB File Content Description: 6 hourly Global Data Assimilation System T126 resolution analysis from NCEP. File Structure Description: Each file contains fields of z, u, v, temp, vert vel, rh, and absolute vorticity, most of which are on 26 mandatory pressure levels (1000 - 10mb). vv is on 1000-100mb and rh is on 1000-300mb. There are additional single level fields as well, for example, boundary level winds, temps, and rh, trop temp, pressure and winds. The grid is a 1 x 1 deg global grid (GRIB grid #3). The file is in GRIB format. Record/Line Format: 26 GRIB records containing atmospheric temperatures (K) at 26 pressure levels 21 GRIB records containing water vapor mixing ratios (g/kg) at 21 pressure levels 1 GRIB record containing a land mask (0=water, 1=land) 1 GRIB record containing surface temperature (K) 1 GRIB record containing pressure (hPa) at mean sea level 1 GRIB record containing precipitable water (g/cm**2) 1 GRIB record containing surface wind u component (m/s) 1 GRIB record containing surface wind v component (m/s) 1 GRIB record containing ice concentration (%) ------------------------------------------------------------------------------ Name: 6 hourly Global Forecast System (GFS) Numerical Weather Predition Fields Example File Name: gfs.tyy.051201.pgrbfxx where xx is the forecast time step for the yy hour analysis (run) time. Used by IMAPP Products: MODIS Cloud Mask and Atmospheric Profiles (MOD35, MOD07) These files are used in the Cloud Mask and Atmospheric Profiles processing for real-time execution when the GDAS analysis files matching the overpass times are not available. The GDAS files are available from 6-9 hours after real-time. The GDAS files should be used whenever possible, because they are scientifically better suited for retrievals. The GDAS files should always be used for the MOD06CT Cloud Top Properties processing, even if the files are behind real-time. AIRS Clear Sky Retrievals AMSU Liquied Water Path (LWP) File Type: Binary GRIB File Content Description: 6 hourly Global Data Assimilation System T126 resolution analysis from NCEP. File Structure Description: Each file contains fields of z, u, v, temp, vert vel, rh, and absolute vorticity, most of which are on 26 mandatory pressure levels (1000 - 10mb). vv is on 1000-100mb and rh is on 1000-300mb. There are additional single level fields as well, for example, boundary level winds, temps, and rh, trop temp, pressure and winds. The grid is a 1 x 1 deg global grid (GRIB grid #3). The file is in GRIB format. Record/Line Format: 26 GRIB records containing atmospheric temperatures (K) at 26 pressure levels 21 GRIB records containing water vapor mixing ratios (g/kg) at 21 pressure levels 1 GRIB record containing a land mask (0=water, 1=land) 1 GRIB record containing surface temperature (K) 1 GRIB record containing pressure (hPa) at mean sea level 1 GRIB record containing precipitable water (g/cm**2) 1 GRIB record containing surface wind u component (m/s) 1 GRIB record containing surface wind v component (m/s) 1 GRIB record containing ice concentration (%) ------------------------------------------------------------------------------ Name: Weekly Optimum Interpolation (OI) Sea Surface Temperature (SST) Analysis Example File Name: oisst.20050608 Used by IMAPP Products: MODIS Cloud Mask (MOD35), Cloud Top Properties (MOD06) and Sea Surface Temperature (MOD28) AMSU Liquied Water Path (LWP) File Type: Binary File Source: NCEP File Content Description: Weekly Reynolds Sea Surface Temperature The week starts on Wednesday and ends on Tuesday. File Structure Description: Each file contains Reynolds SST (C) on a 1 degree global grid. Record/Line Format: The files were written in IEEE binary (big-endian). Each file contains four records described as follows: rec 1: date and version number (8 4-byte integer words) rec 2: gridded sst values in degC (360*180 4-byte real words) rec 3: normalized error variance (360*180 4-byte real words) rec 4: gridded ice concentration (360*180 1-byte integer words) (This is the layout as seen by a fortran code reading sequential access data) Fore more detailed information concerning this product, please refer to this web page: ftp://ftpprd.ncep.noaa.gov/pub/cmb/sst/oisst_v2/README ------------------------------------------------------------------------------