Dear All,<br><br>Has anyone successfully opened IBTraCS file in GrADS? I have recently found about this typhoon data archive combining different agencies best track in a netcdf file format, the data is downloadable in this link:<br>
<a href="ftp://eclipse.ncdc.noaa.gov/pub/ibtracs/v03r03/wmo/netcdf/year/">ftp://eclipse.ncdc.noaa.gov/pub/ibtracs/v03r03/wmo/netcdf/year/</a> <br clear="all"><br>However, when I tried to open it in GrADS 2.0.1, I received this error:<br>
<br><i>ga-> sdfopen <a href="http://Year.1901.ibtracs_wmo.v03r03.nc">Year.1901.ibtracs_wmo.v03r03.nc</a> <br>Scanning self-describing file: <a href="http://Year.1901.ibtracs_wmo.v03r03.nc">Year.1901.ibtracs_wmo.v03r03.nc</a><br>
gadsdf: SDF file has no discernable X coordinate.<br> To open this file with GrADS, use a descriptor file with an XDEF entry.<br> Documentation is at <a href="http://iges.org/grads/gadoc/SDFdescriptorfile.html">http://iges.org/grads/gadoc/SDFdescriptorfile.html</a></i><br>
<br>I tried to read the documentation given above but I still can't figure out how to make a descriptor file for the said file. ncdump gives the following details about the file:<br><br>dimensions:<br> storm = UNLIMITED ; // (16 currently)<br>
time = 137 ;<br> ncharsn = 13 ;<br> ncharnm = 55 ;<br> center = 24 ;<br> ncharcn = 10 ;<br>variables:<br> char storm_sn(storm, ncharsn) ;<br> storm_sn:long_name = "Storm serial number" ;<br>
char name(storm, ncharnm) ;<br> name:long_name = "Storm name" ;<br> short numObs(storm) ;<br> numObs:long_name = "Number of observations for the storm" ;<br>
short season(storm) ;<br> season:long_name = "Year based on season" ;<br> season:Note = "Following WMO,\n",<br> "NH Seasons begin 1 January and \n",<br>
"SH Seasons begin 1 July the prior year" ;<br> byte track_type(storm) ;<br> track_type:long_name = "Track type" ;<br> track_type:key = "0 = main - cyclogenesis to cyclolysis\n",<br>
"1 = merge - cyclogenesis to merger\n",<br> "2 = split - split to cyclolysis\n",<br> "3 = other - split to merger" ;<br> byte genesis_basin(storm) ;<br>
genesis_basin:long_name = "Basin of genesis" ;<br> genesis_basin:units = " " ;<br> genesis_basin:key = "0 = NA - North Atlantic\n",<br> "1 = SA - South Atlantic\n",<br>
"2 = WP - West Pacific\n",<br> "3 = EP - East Pacific\n",<br> "4 = SP - South Pacific\n",<br> "5 = NI - North Indian\n",<br>
"6 = SI - South Indian\n",<br> "7 = AS - Arabian Sea\n",<br> "8 = BB - Bay of Bengal\n",<br> "9 = EA - Eastern Australia\n",<br>
"10 = WA - Western Australia\n",<br> "11 = CP - Central Pacific\n",<br> "12 = CS - Carribbean Sea\n",<br> "13 = GM - Gulf of Mexico\n",<br>
"14 = MM - Missing" ;<br> genesis_basin:Note = "Based on where the storm began" ;<br> byte num_basins(storm) ;<br> num_basins:long_name = "Number of basins through which the storm passes" ;<br>
num_basins:units = " " ;<br> byte basin(storm, time) ;<br> basin:long_name = "Basin" ;<br> basin:units = " " ;<br> basin:key = "0 = NA - North Atlantic\n",<br>
"1 = SA - South Atlantic\n",<br> "2 = WP - West Pacific\n",<br> "3 = EP - East Pacific\n",<br> "4 = SP - South Pacific\n",<br>
"5 = NI - North Indian\n",<br> "6 = SI - South Indian\n",<br> "7 = AS - Arabian Sea\n",<br> "8 = BB - Bay of Bengal\n",<br>
"9 = EA - Eastern Australia\n",<br> "10 = WA - Western Australia\n",<br> "11 = CP - Central Pacific\n",<br> "12 = CS - Carribbean Sea\n",<br>
"13 = GM - Gulf of Mexico\n",<br> "14 = MM - Missing" ;<br> basin:Note = "Based on present location" ;<br> basin:_FillValue = -127b ;<br>
byte wind_avg_period(center) ;<br> wind_avg_period:long_name = "Wind speed averaging period" ;<br> wind_avg_period:units = "min" ;<br> wind_avg_period:_FillValue = -127b ;<br>
char source(center, ncharcn) ;<br> source:long_name = "Source name" ;<br> source:Note = "This order matches the dimension in source_* variables" ;<br> double time_wmo(storm, time) ;<br>
time_wmo:long_name = "Modified Julian Day" ;<br> time_wmo:units = "days since 1858-11-17 00:00:00" ;<br> time_wmo:_FillValue = 9.96921e+36 ;<br> short lat_wmo(storm, time) ;<br>
lat_wmo:long_name = "Storm center latitude" ;<br> lat_wmo:units = "degrees_north" ;<br> lat_wmo:scale_factor = 0.01f ;<br> lat_wmo:_FillValue = -32767s ;<br>
short lon_wmo(storm, time) ;<br> lon_wmo:long_name = "Storm center longitude" ;<br> lon_wmo:units = "degrees_east" ;<br> lon_wmo:scale_factor = 0.01f ;<br>
lon_wmo:_FillValue = -32767s ;<br> byte alt(storm, time) ;<br> alt:long_name = "Altitude" ;<br> alt:units = "m" ;<br> alt:_FillValue = -127b ;<br>
alt:note = "only included in an attempt to have THREDDS recognize the file as a trajectory" ;<br> short wind_wmo(storm, time) ;<br> wind_wmo:long_name = "Maximum Sustained Wind (MSW)" ;<br>
wind_wmo:units = "kt" ;<br> wind_wmo:scale_factor = 0.1f ;<br> wind_wmo:_FillValue = -32767s ;<br> short pres_wmo(storm, time) ;<br> pres_wmo:long_name = "Minimum Central Pressure (MCP)" ;<br>
pres_wmo:units = "mb" ;<br> pres_wmo:scale_factor = 0.1f ;<br> pres_wmo:_FillValue = -32767s ;<br> byte sub_basin(storm, time) ;<br> sub_basin:long_name = "Sub-Basin" ;<br>
sub_basin:units = " " ;<br> sub_basin:key = "0 = NA - North Atlantic\n",<br> "1 = SA - South Atlantic\n",<br> "2 = WP - West Pacific\n",<br>
"3 = EP - East Pacific\n",<br> "4 = SP - South Pacific\n",<br> "5 = NI - North Indian\n",<br> "6 = SI - South Indian\n",<br>
"7 = AS - Arabian Sea\n",<br> "8 = BB - Bay of Bengal\n",<br> "9 = EA - Eastern Australia\n",<br> "10 = WA - Western Australia\n",<br>
"11 = CP - Central Pacific\n",<br> "12 = CS - Carribbean Sea\n",<br> "13 = GM - Gulf of Mexico\n",<br> "14 = MM - Missing" ;<br>
sub_basin:Note = "Based on present location" ;<br> sub_basin:_FillValue = -127b ;<br> byte nature_wmo(storm, time) ;<br> nature_wmo:long_name = "Storm nature" ;<br>
nature_wmo:key = "0 = TS - Tropical\n",<br> "1 = SS - Subtropical\n",<br> "2 = ET - Extratropical\n",<br> "3 = DS - Disturbance\n",<br>
"4 = MX - Mix of conflicting reports\n",<br> "5 = NR - Not Reported\n",<br> "6 = MM - Missing\n",<br> "7 = - Missing" ;<br>
nature_wmo:Note = "Based on classification from original sources" ;<br> nature_wmo:_FillValue = -127b ;<br> byte source_wmo(storm, time) ;<br> source_wmo:long_name = "Source used as WMO agency" ;<br>
source_wmo:flag_values = "0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23" ;<br> source_wmo:flag_meanings = "hurdat_atl td9636 reunion atcf ds824_sh ds824_ni bom ds824_au jtwc_sh jtwc_wp ds824_wp jtwc_io cma hurdat_epa jtwc_ep ds824_ep jtwc_cp tokyo neumann hko cphc wellington newdelhi nadi" ;<br>
source_wmo:_FillValue = -127b ;<br><br>// global attributes:<br> :Title = "IBTrACS-WMO: NetCDF reformat" ;<br> :Version = "v03r03" ;<br> :Description = "IBTrACS-WMO data reformatted to contain \n",<br>
"all data in one netCDF file. Also an attempt has been made\n",<br> "to have the data appear as trajectories in the CDM" ;<br> :cdm_datatype = "Trajectory" ;<br>
:trajectoryDimension = "storm" ;<br> :Conventions = "CF-1.0" ;<br>}<br><br><br>Sorry for the long mail. Thanks in advance for any help..<br><br>Best regards,<br><br>Mar<br>
<br><br>