README file for merged GV and GFS files This directory contains netCDF data files that hold selected variables from the NCAR Gulfstream V (GV) aircraft and large-scale meteorological variables interpolated in space and time from the high-resolution NCEP Global Forecast System (GFS) 6-hourly global analyses. The files also include a number of derived variables, such as equivalent latitude, potential temperature lapse rate (stability), temperature at the tropopause, etc. The equivalent latitude suffers from ambiguities when the isentropic surface of interest intersects the ground. Therefore, the eqlat_GFS variable has attributes listing the theta surfaces on which it was computed and the amount of missing data on each surface. This can be used as a measure of the reliability of the equivalent latitude. See the README file for the GFS data files for details of the GFS input data. An ncdump of a sample merged file is given below. For further information contact: Prof. Kenneth P. Bowman Department of Atmospheric Sciences 3150 TAMU Texas A&M University College Station, TX 77843-3150 k-bowman@tamu.edu NCDUMP of sample file netcdf start08_rf01_gfs_v06 { dimensions: date_string = 20 ; Time = UNLIMITED ; // (25561 currently) variables: int Time(Time) ; Time:long_name = "time of measurement" ; Time:standard_name = "time" ; Time:units = "seconds since 2008-04-18 14:58:00 +0000" ; float LONC(Time) ; LONC:_FillValue = NaNf ; LONC:units = "degree_E" ; LONC:long_name = "GPS-Corrected Inertial Longitude" ; LONC:valid_range = -180.f, 180.f ; LONC:Category = "Position" ; LONC:standard_name = "longitude" ; LONC:DataQuality = "Good" ; LONC:Dependencies = "1 LATC" ; LONC:coordinate_system = "WGS84" ; float LATC(Time) ; LATC:_FillValue = NaNf ; LATC:units = "degree_N" ; LATC:long_name = "GPS-Corrected Inertial Latitude" ; LATC:valid_range = -90.f, 90.f ; LATC:Category = "Position" ; LATC:standard_name = "latitude" ; LATC:DataQuality = "Good" ; LATC:Dependencies = "11 LAT LON GGLAT GGLON VNS VEW GGVNS GGVEW ROLL GGNSAT GGSTATUS" ; LATC:coordinate_system = "WGS84" ; float GGALT(Time) ; GGALT:_FillValue = NaNf ; GGALT:units = "m" ; GGALT:long_name = "Reference GPS Altitude (MSL)" ; GGALT:Category = "Position" ; GGALT:standard_name = "altitude" ; GGALT:SampledRate = 1 ; GGALT:DataQuality = "Good" ; float PSXC(Time) ; PSXC:_FillValue = NaNf ; PSXC:units = "hPa" ; PSXC:long_name = "Corrected Static Pressure, Reference" ; PSXC:Category = "Atmos. State" ; PSXC:standard_name = "air_pressure" ; PSXC:DataQuality = "Good" ; float PALT(Time) ; PALT:_FillValue = NaNf ; PALT:units = "m" ; PALT:long_name = "NACA Pressure Altitude" ; PALT:Category = "Position" ; PALT:standard_name = "altitude" ; PALT:DataQuality = "Good" ; float PALTF(Time) ; PALTF:_FillValue = NaNf ; PALTF:units = "feet" ; PALTF:long_name = "NACA Pressure Altitude" ; PALTF:Category = "Position" ; PALTF:standard_name = "altitude" ; PALTF:DataQuality = "Good" ; float UIC(Time) ; UIC:_FillValue = NaNf ; UIC:units = "m/s" ; UIC:long_name = "GPS-Corrected Wind Vector, East Component" ; UIC:Category = "Wind" ; UIC:standard_name = "eastward_wind" ; UIC:DataQuality = "Good" ; float VIC(Time) ; VIC:_FillValue = NaNf ; VIC:units = "m/s" ; VIC:long_name = "GPS-Corrected Wind Vector, North Component" ; VIC:Category = "Wind" ; VIC:standard_name = "northward_wind" ; VIC:DataQuality = "Good" ; float WIC(Time) ; WIC:_FillValue = NaNf ; WIC:units = "m/s" ; WIC:long_name = "GPS-Corrected Wind Vector, Vertical Gust Component" ; WIC:Category = "Wind" ; WIC:standard_name = "upward_air_velocity" ; WIC:DataQuality = "Good" ; float WSC(Time) ; WSC:_FillValue = NaNf ; WSC:units = "m/s" ; WSC:long_name = "GPS-Corrected Horizontal Wind Speed" ; WSC:Category = "Wind" ; WSC:standard_name = "wind_speed" ; WSC:DataQuality = "Good" ; float WDC(Time) ; WDC:_FillValue = NaNf ; WDC:units = "degree_T" ; WDC:long_name = "GPS-Corrected Horizontal Wind Direction" ; WDC:Category = "Wind" ; WDC:standard_name = "wind_from_direction" ; WDC:DataQuality = "Good" ; float ATX(Time) ; ATX:_FillValue = NaNf ; ATX:units = "deg_C" ; ATX:long_name = "Ambient Temperature, Reference" ; ATX:Category = "Atmos. State" ; ATX:standard_name = "air_temperature" ; ATX:DataQuality = "Good" ; float TASX(Time) ; TASX:_FillValue = NaNf ; TASX:units = "m/s" ; TASX:long_name = "Aircraft True Airspeed, Reference" ; TASX:Category = "Aircraft State" ; TASX:standard_name = "platform_speed_wrt_air" ; TASX:DataQuality = "Good" ; float THETA(Time) ; THETA:_FillValue = NaNf ; THETA:units = "K" ; THETA:long_name = "Potential Temperature" ; THETA:Category = "Thermodynamic" ; THETA:standard_name = "air_potential_temperature" ; THETA:DataQuality = "Good" ; float THETAE(Time) ; THETAE:_FillValue = NaNf ; THETAE:units = "K" ; THETAE:long_name = "Equivalent Potential Temperature" ; THETAE:Category = "Thermodynamic" ; THETAE:DataQuality = "Good" ; float THETAV(Time) ; THETAV:_FillValue = NaNf ; THETAV:units = "K" ; THETAV:long_name = "Virtual Potential Temperature" ; THETAV:Category = "Thermodynamic" ; THETAV:DataQuality = "Good" ; float DPXC(Time) ; DPXC:_FillValue = NaNf ; DPXC:units = "deg_C" ; DPXC:long_name = "Dew Point Temperature, Reference" ; DPXC:Category = "Atmos. State" ; DPXC:standard_name = "dew_point_temperature" ; DPXC:DataQuality = "Good" ; float EDPC(Time) ; EDPC:_FillValue = NaNf ; EDPC:units = "hPa" ; EDPC:long_name = "Ambient Water Vapor Pressure, Reference" ; EDPC:Category = "Thermodynamic" ; EDPC:DataQuality = "Good" ; float MR(Time) ; MR:_FillValue = NaNf ; MR:units = "gram/kg" ; MR:long_name = "Mixing Ratio, T-Electric" ; MR:Category = "Atmos. State" ; MR:DataQuality = "Good" ; float RHODR(Time) ; RHODR:_FillValue = NaNf ; RHODR:units = "gram/m3" ; RHODR:long_name = "Absolute Humidity, T-Electric Right" ; RHODR:Category = "Atmos. State" ; RHODR:DataQuality = "Good" ; float RHUM(Time) ; RHUM:_FillValue = NaNf ; RHUM:units = "%" ; RHUM:long_name = "Relative Humidity" ; RHUM:Category = "Atmos. State" ; RHUM:DataQuality = "Good" ; float SOLAZ(Time) ; SOLAZ:_FillValue = NaNf ; SOLAZ:units = "radian" ; SOLAZ:long_name = "Solar Azimuth Angle" ; SOLAZ:Category = "Derived" ; SOLAZ:DataQuality = "Good" ; SOLAZ:Dependencies = "1 SOLZE" ; float SOLDE(Time) ; SOLDE:_FillValue = NaNf ; SOLDE:units = "radian" ; SOLDE:long_name = "Solar Declination Angle" ; SOLDE:Category = "Derived" ; SOLDE:DataQuality = "Good" ; SOLDE:Dependencies = "1 SOLZE" ; float SOLEL(Time) ; SOLEL:_FillValue = NaNf ; SOLEL:units = "radian" ; SOLEL:long_name = "Solar Elevation Angle" ; SOLEL:Category = "Derived" ; SOLEL:DataQuality = "Good" ; SOLEL:Dependencies = "1 SOLZE" ; float SOLZE(Time) ; SOLZE:_FillValue = NaNf ; SOLZE:units = "radian" ; SOLZE:long_name = "Solar Zenith Angle" ; SOLZE:Category = "Derived" ; SOLZE:DataQuality = "Good" ; SOLZE:Dependencies = "8 YEAR MONTH DAY HOUR MINUTE SECOND GGLAT GGLON" ; char Time_ISO(Time, date_string) ; Time_ISO:long_name = "Date and time in ISO 8601 format" ; Time_ISO:units = "YYYY-MM-DD hh:mm:ss" ; float u_GFS(Time) ; u_GFS:units = "m s^-1" ; u_GFS:long_name = "U-component of the velocity" ; u_GFS:Category = "GFS analysis interpolated variable" ; u_GFS:missing_value = NaNf ; float v_GFS(Time) ; v_GFS:units = "m s^-1" ; v_GFS:long_name = "V-component of the velocity" ; v_GFS:Category = "GFS analysis interpolated variable" ; v_GFS:missing_value = NaNf ; float w_GFS(Time) ; w_GFS:units = "hPa s^-1" ; w_GFS:long_name = "W-component of the velocity" ; w_GFS:Category = "GFS analysis interpolated variable" ; w_GFS:missing_value = NaNf ; float T_GFS(Time) ; T_GFS:units = "K" ; T_GFS:long_name = "Temperature" ; T_GFS:Category = "GFS analysis interpolated variable" ; T_GFS:missing_value = NaNf ; float theta_GFS(Time) ; theta_GFS:units = "K" ; theta_GFS:long_name = "Potential temperature" ; theta_GFS:Category = "GFS analysis interpolated variable" ; theta_GFS:missing_value = NaNf ; float hgt_GFS(Time) ; hgt_GFS:units = "m" ; hgt_GFS:long_name = "Geopotential height" ; hgt_GFS:Category = "GFS analysis interpolated variable" ; hgt_GFS:missing_value = NaNf ; float SH_GFS(Time) ; SH_GFS:units = "kg kg^-1" ; SH_GFS:long_name = "Specific humidity" ; SH_GFS:Category = "GFS analysis interpolated variable" ; SH_GFS:missing_value = NaNf ; float pv_GFS(Time) ; pv_GFS:units = "s^-1" ; pv_GFS:long_name = "Potential vorticity" ; pv_GFS:Category = "GFS analysis interpolated variable" ; pv_GFS:missing_value = NaNf ; float eqlat_GFS(Time) ; eqlat_GFS:units = "degrees" ; eqlat_GFS:long_name = "Equivalent latitude" ; eqlat_GFS:potential_temperature_surface = 250.f, 252.5f, 255.f, 257.5f, 260.f, 262.5f, 265.f, 267.5f, 270.f, 272.5f, 275.f, 277.5f, 280.f, 282.5f, 285.f, 287.5f, 290.f, 292.5f, 295.f, 297.5f, 300.f, 302.5f, 305.f, 307.5f, 310.f, 312.5f, 315.f, 317.5f, 320.f, 322.5f, 325.f, 327.5f, 330.f, 332.5f, 335.f, 337.5f, 340.f, 342.5f, 345.f, 347.5f, 350.f, 352.5f, 355.f, 357.5f, 360.f, 362.5f, 365.f, 367.5f, 370.f, 372.5f, 375.f, 377.5f, 380.f, 382.5f, 385.f, 387.5f, 390.f, 392.5f, 395.f, 397.5f, 400.f, 402.5f, 405.f, 407.5f, 410.f, 412.5f, 415.f, 417.5f, 420.f, 422.5f, 425.f, 427.5f, 430.f, 432.5f, 435.f, 437.5f, 440.f, 442.5f, 445.f, 447.5f, 450.f, 452.5f, 455.f, 457.5f, 460.f, 462.5f, 465.f, 467.5f, 470.f, 472.5f, 475.f, 477.5f, 480.f, 482.5f, 485.f, 487.5f, 490.f, 492.5f, 495.f, 497.5f, 500.f ; eqlat_GFS:percent_missing_grid_points = 94.60223f, 91.56117f, 87.77097f, 83.77821f, 80.54877f, 78.09953f, 76.42235f, 74.73702f, 72.74652f, 69.62257f, 65.53533f, 60.80292f, 56.60868f, 52.45587f, 47.99775f, 44.19488f, 40.15963f, 35.09115f, 30.1057f, 23.84109f, 13.36715f, 5.267861f, 4.005112f, 2.752761f, 1.934438f, 1.173985f, 0.249566f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 94.65317f, 91.94577f, 88.03997f, 83.85371f, 80.44147f, 78.15016f, 76.41676f, 74.70808f, 72.39553f, 69.50985f, 65.22382f, 60.64695f, 56.3035f, 52.33154f, 48.148f, 44.36894f, 40.35795f, 35.34659f, 30.28775f, 23.94206f, 12.73299f, 4.305314f, 2.667161f, 1.596258f, 0.9244189f, 0.4680869f, 0.1255365f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 94.38507f, 92.30444f, 88.29134f, 84.08429f, 80.35452f, 78.25626f, 76.58073f, 74.77907f, 72.42823f, 69.36292f, 64.6623f, 60.29369f, 55.86209f, 52.09298f, 47.92707f, 44.29299f, 40.37001f, 35.5523f, 29.74477f, 23.0202f, 10.49986f, 1.881993f, 0.8373119f, 0.3285349f, 0.08665485f, 0.01265914f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f ; eqlat_GFS:GFS_analysis_date = "20080418T120000Z, 20080418T180000Z, 20080419T000000Z" ; eqlat_GFS:Category = "GFS analysis interpolated variable" ; eqlat_GFS:missing_value = NaNf ; float dthetadz_GFS(Time) ; dthetadz_GFS:units = "K km^-1" ; dthetadz_GFS:long_name = "Static stability d(theta)/dz" ; dthetadz_GFS:Category = "GFS analysis interpolated variable" ; dthetadz_GFS:missing_value = NaNf ; float p_trop_GFS(Time) ; p_trop_GFS:units = "Pa" ; p_trop_GFS:long_name = "Pressure at the tropopause" ; p_trop_GFS:Category = "GFS analysis interpolated variable" ; p_trop_GFS:missing_value = NaNf ; float z_trop_GFS(Time) ; z_trop_GFS:units = "m" ; z_trop_GFS:long_name = "Geopotential height of the tropopause" ; z_trop_GFS:Category = "GFS analysis interpolated variable" ; z_trop_GFS:missing_value = NaNf ; float T_trop_GFS(Time) ; T_trop_GFS:units = "K" ; T_trop_GFS:long_name = "Temperature at the tropopause" ; T_trop_GFS:Category = "GFS analysis interpolated variable" ; T_trop_GFS:missing_value = NaNf ; byte trop_type_GFS(Time) ; trop_type_GFS:long_name = "GFS Tropopause Type" ; trop_type_GFS:Category = "GFS analysis interpolated variable quality" ; trop_type_GFS:Description = "1 = Primary Tropopause, 2 = Secondary Tropopause or Indeterminate" ; float z_trop2_GFS(Time) ; z_trop2_GFS:units = "m" ; z_trop2_GFS:long_name = "Geopotential height of the secondary tropopause" ; z_trop2_GFS:Category = "GFS analysis interpolated variable" ; z_trop2_GFS:Description = "Computed by Homeyer & Bowman using GFS analysis and WMO definition" ; z_trop2_GFS:missing_value = NaNf ; float p_trop2_GFS(Time) ; p_trop2_GFS:units = "Pa" ; p_trop2_GFS:long_name = "Pressure at the secondary tropopause" ; p_trop2_GFS:Category = "GFS analysis interpolated variable" ; p_trop2_GFS:Description = "Computed by Homeyer & Bowman using GFS analysis and WMO definition" ; p_trop2_GFS:missing_value = NaNf ; float z_pv2_GFS(Time) ; z_pv2_GFS:units = "m" ; z_pv2_GFS:long_name = "Geopotential height of the 2.0 pvu surface" ; z_pv2_GFS:Category = "GFS analysis interpolated variable" ; z_pv2_GFS:missing_value = NaNf ; float p_pv2_GFS(Time) ; p_pv2_GFS:units = "hPa" ; p_pv2_GFS:long_name = "Pressure at the 2.0 pvu surface" ; p_pv2_GFS:Category = "GFS analysis interpolated variable" ; p_pv2_GFS:missing_value = NaNf ; float theta_pv2_GFS(Time) ; theta_pv2_GFS:units = "K" ; theta_pv2_GFS:long_name = "Potential temperature at the 2.0 pvu surface" ; theta_pv2_GFS:Category = "GFS analysis interpolated variable" ; theta_pv2_GFS:missing_value = NaNf ; float z_pv4_GFS(Time) ; z_pv4_GFS:units = "m" ; z_pv4_GFS:long_name = "Geopotential height of the 4.0 pvu surface" ; z_pv4_GFS:Category = "GFS analysis interpolated variable" ; z_pv4_GFS:missing_value = NaNf ; float p_pv4_GFS(Time) ; p_pv4_GFS:units = "hPa" ; p_pv4_GFS:long_name = "Pressure at the 4.0 pvu surface" ; p_pv4_GFS:Category = "GFS analysis interpolated variable" ; p_pv4_GFS:missing_value = NaNf ; float theta_pv4_GFS(Time) ; theta_pv4_GFS:units = "K" ; theta_pv4_GFS:long_name = "Potential temperature at the 4.0 pvu surface" ; theta_pv4_GFS:Category = "GFS analysis interpolated variable" ; theta_pv4_GFS:missing_value = NaNf ; float z_pv8_GFS(Time) ; z_pv8_GFS:units = "m" ; z_pv8_GFS:long_name = "Geopotential height of the 8.0 pvu surface" ; z_pv8_GFS:Category = "GFS analysis interpolated variable" ; z_pv8_GFS:missing_value = NaNf ; float p_pv8_GFS(Time) ; p_pv8_GFS:units = "hPa" ; p_pv8_GFS:long_name = "Pressure at the 8.0 pvu surface" ; p_pv8_GFS:Category = "GFS analysis interpolated variable" ; p_pv8_GFS:missing_value = NaNf ; float theta_pv8_GFS(Time) ; theta_pv8_GFS:units = "K" ; theta_pv8_GFS:long_name = "Potential temperature at the 8.0 pvu surface" ; theta_pv8_GFS:Category = "GFS analysis interpolated variable" ; theta_pv8_GFS:missing_value = NaNf ; // global attributes: :Contents = "GFS analysis fields interpolated to HIAPER flight track" ; :Author = "Kenneth P. Bowman, Texas A&M University" ; :Input_file = "/data/GV/rf01/start08_rf01_gv_v05.nc" ; :Source = "NCAR Research Aviation Facility" ; :Address = "P.O. Box 3000, Boulder, CO 80307-3000" ; :Phone = "(303) 497-1030" ; :Conventions = "NCAR-RAF/nimbus" ; :ConventionsURL = "http://www.eol.ucar.edu/raf/Software/netCDF.html" ; :ConventionsVersion = "1.3" ; :ProcessorRevision = "4227" ; :ProcessorURL = "http://svn/svn/raf/trunk/nimbus" ; :DateProcessed = "2008-11-29 19:15:44 +0000" ; :ProjectName = "START08" ; :Aircraft = "N677F" ; :ProjectNumber = "START08" ; :FlightNumber = "rf01" ; :FlightDate = "04/18/2008" ; :InterpolationMethod = "Linear" ; :coordinates = "LONC LATC GGALT Time" ; :wind_field = "WSC WDC WIC" ; :landmarks = "39.9083 -105.116 BJC" ; :TimeInterval = "14:58:00-22:04:00" ; :Categories = "Position,Thermodynamic,Aircraft State,Atmos. State,Liquid Water,Uncorr\'d Raw,Wind,PMS Probe,Housekeeping,Chemistry,Radiation,Non-Standard" ; :DGPS_datamerged = "2008-12-12 JAG" ; :History = "Thu Jul 2 13:10:42 2009: ncatted -a history,global,d,c, ./START08rf01.nc" ; }