May 7, 1996 Accessing and converting UWM/COADS fields _________________________________________ The final part of this memorandum is Arlindo daSilva's document containing instructions for accessing the UWM/COADS fields in netCDF format via anonymous ftp. Various README files in the subdirectories mentioned below contain detailed instructions for reading the fields via programs written in Fortran. Here we supply the most important routines needed, together with programs to plot (NCAR graphics) the raw data (1 x 1 deg. resolution) and to convert the data to a grid specified by the user. 1) To translate the netCDF files, the following programs are needed (in addition to the netCDF library on your system): newtest.f (based on daSilva's 'test.f') uwmcdf.f uwmcdf.h netcdf.inc Makefile Various parameters related to the latitude/longitude extent of your domain must be changed within newtest.f (see the comments therein). To run newtest.f : make newtest.x newtest.x > newtest.out The output files (to be renamed by the user) will be the data file for your domain in 'pakked' format on unit fort.10, and a mask file (to indicate points on land) on unit fort.20 (see comments within newtest.f). 2) Program plot.f will plot the output of newtest.f . Program plot.f requires units fort.10 (data) and fort.20 (mask) as input. 3) Program transgrd.f will convert the COADS data to a grid specified by the user. It requires units fort.10 (data) and fort.20 (mask) as input. It also requires a bottom topography file (on unit fort.9) for the user's grid. At present the program is set up to convert to a Mercator projection grid. Comments within the program indicate parameters that need to be specified by the user for his particular configuration. =========================================================================== --------------------------------------------------------------------------- Accessing UWM/COADS Fields by FTP --------------------------------- Last Revision: August 23, 1994 CONTENTS -------- Introduction Important Notice Data Set Overview Access Software and Climatological Data List of Objective Analyzed Files Further Information INTRODUCTION ------------ This document describes how to obtain by anonymous ftp portions of the UWM/COADS Data Set as well as access software. You will also find instructions to obtain the full data set from NASA/GSFC Unitree System (NASA/GSFC folks only). This data set was produced at University of Wisconsin-Milwaukee (UWM) by Arlindo M. da Silva and Christine C. Young in collaboration with Syd Levitus from NOAA/National Oceanographic Data Center. Since then both AMdS and CCY have left UWM, and inquires about the data set should be directed to the address below. Currently this data set is in beta-test phase. IMPORTANT NOTICE ---------------- We request that users of this data inform us of its intended use and provide an email address where we could notify them about future releases and improvements. DATA SET OVERVIEW ----------------- The UWM/COADS Data Set contains raw and objectively analyzed fields of surface marine anomalies of fluxes of heat, momentum, and fresh water along with several other parameters of interest. These revised monthly mean fields are derived from individual observations in the Comprehensive Ocean-Atmosphere Data Set (COADS) from January 1945 to December 1989 and are analyzed on a 1-degree by 1-degree global grid. Corrections have been made to reduce wind speed bias associated with an erroneous Beaufort equivalent scale, and to quality control night-time fractional cloud cover observations according to the brightness of the sky. Period: 1945-89, monthly surface marine climatology and anomalies. Grid: 1x1 degree, global (climatology also available on a 0.5x0.5 degree grid) Objective Analysis: Successive correction method with Barnes' weight function. Same response function as Levitus' Climatological Atlas of the World Oceans. Unanalyzed monthly means, standard deviation and number of observations also available. Main Features: All calculations from individual observations Wind speed correction (revised Beaufort equivalent scale) Stability dependent transfer coefficients (Large&Pond) Heat and fresh water fluxes fine tuned with oceanic constraints (simple linear inverse calculation). Sensitivity (gradient) fields provided to allow for other oceanic constraints. Data Format: Unidata's NetCDF. Easy to use access subroutines in FORTRAN provided for those unfamiliar with NetCDF. References: The full documentation for this data set is in preparation. The primary reference will be the following NOAA Atlas Series: da Silva, A. M., C. C. Young and S. Levitus, 1994: Atlas of Surface Marine Data 1994, Volume 1: Algorithms and Procedures. NOAA Atlas Series. In preparation. da Silva, A. M., C. C. Young and S. Levitus, 1994: Atlas of Surface Marine Data 1994, Volume 2: Anomalies of Directly Observed Quantities. NOAA Atlas Series. In press. (*) da Silva, A. M., C. C. Young and S. Levitus, 1994: Atlas of Surface Marine Data 1994, Volume 3: Anomalies of Heat and Momentum Fluxes. NOAA Atlas Series. In preparation. da Silva, A. M., C. C. Young and S. Levitus, 1994: Atlas of Surface Marine Data 1994, Volume 4: Anomalies of Fresh Water Fluxes. NOAA Atlas Series. In preparation. da Silva, A. M., C. C. Young and S. Levitus, 1994: Atlas of Surface Marine Data 1994, Volume 5: Anomalies of Miscellaneous Derived Quantities. NOAA Atlas Series. In preparation. (*) Text portion in postscript available by anonymous ftp from niteroi.gsfc.nasa.gov, directory 'pub/uwm_coads/1x1/doc/atlas/' (see below). ACCESS SOFTWARE AND CLIMATOLOGICAL DATA --------------------------------------- Available by anonymous ftp from niteroi.gsfc.nasa.gov (192.225.67.52), directory pub/uwm_coads. Please follow instructions on README file. Directory structure: pub/uwm_coads/1x1/data/ Climatological data files doc/ Postscript files software/ Access software LIST OF OBJECTIVE ANALYZED FILES -------------------------------- File Name Units Description --------- ------------- ---------------------------------- airdens.nc kg/m^3 sea level air density buoy5.nc kg/(m s^3) constrained buoyancy flux cloud.nc fraction of 1. fractional cloudiness dAedSST.nc hPa/K Ae sensitivity to SST dAxdSST.nc W/m^2/K Achi sensitivity to SST dLdSST.nc W/m^2/K latent heat flux sensitivity to SST dOdSST.nc W/m^2/K longwave sensitivity to SST dQdSST.nc W/m^2/K constrained net heat flux (netheat) sensitivity to SST dSdSST.nc W/m^2/K sensible heat flux sensitivity to SST evaprate.nc mm/3 hours evaporation rate fvcubed.nc m^3/s^3 ocean friction velocity cubed icemask.nc (none) icemask; ice = 1. latent3.nc W/m^2 corrected latent heat flux longrad.nc W/m^2 outgoing longwave radiation netheat5.nc W/m^2 constrained net outgoing heat flux precip6.nc mm/3 hours precipitation rate qair.nc g/kg specific humidity qs_qa.nc g/kg qsea minus qair qsea.nc g/kg sea level specific humidity rh.nc % relative humidity sat.nc C sea level air temperature sensib3.nc W/m^2 corrected sensible heat flux shortrad.nc W/m^2 incoming short wave radiation slp.nc mb sea level air pressure sst_sat.nc C sea minus air temperature sst.nc C sea surface temperature taux3.nc N/m^2 corrected zonal wind stress tauy3.nc N/m^2 corrected meridional stress u3.nc m/s corrected zonal wind ua.nc K, m/s zonal heat flux uq.nc m/s zonal moisture flux v3.nc m/s corrected meridional wind va.nc K, m/s meridional heat flux vappress.nc mb vapor pressure virtemp.nc C virtual temperature vq.nc m/s meridional moisture flux w3.nc m/s corrected wind speed zdl.nc (unitless) 10m/(Monin Obukov length) FURTHER INFORMATION ------------------- Please contact: *---------------------------------------------------------------------* | | | ^|^ ARLINDO MORAES DA SILVA, JR | | | Data Assimilation Office, NASA/GSFC | | _|_ 7501 Forbes Blvd, Suite 200 | | @ ___|___|__ Seabrook, MD 20706 | | _|_|__________|_______/ | | \ o o o o o o o / Office: (301) 805-7959 | | \_______________/ FAX: (301) 805-7960 | | ^^^^^^^^^^^^^^^^^^^^^^^^ E-mail: dasilva@gsfc.nasa.gov | | | *---------------------------------------------------------------------* ===========================================================================