Brian,
I was unable to access that bzip2 file URL via OPeNDAP
http://data.nodc.noaa.gov/opendap/ghrsst/L4/GLOB/JPL_OUROCEAN/G1SST/2010/160/20100609-JPL_OUROCEAN-L4UHfnd-GLOB-v01-fv01_0-G1SST.nc.bz2
But I did try downloading the file, unzipping it, and putting it on our TDS:
http://geoport.whoi.edu/thredds/catalog/usgs/data1/rsignell/test/catalog.html?dataset=usgs/data1/rsignell/test/20100609-JPL_OUROCEAN-L4UHfnd-GLOB-v01-fv01_0-G1SST.nc
And if I then try accessing the OPeNDAP URL
http://geoport.whoi.edu/thredds/dodsC/usgs/data1/rsignell/test/20100609-JPL_OUROCEAN-L4UHfnd-GLOB-v01-fv01_0-G1SST.nc
it works fine.
I note that by using BZIP2 compression, NODC manages to compress this
2.8GB NetCDF3 file down to 123MB, but of course, that makes it very
awkward to extract data from using OPeNDAP. If instead they
converted the NetCDF3 to NetCDF4, they could get the file easily down
to 250MB by using simple deflation, and the efficiency of extraction
would be *way* better.
Check out the NetCDF4 chunked version:
http://geoport.whoi.edu/thredds/catalog/usgs/data1/rsignell/test/catalog.html?dataset=usgs/data1/rsignell/test/sst_netcdf4_chunk100.nc
-Rich
On Thu, Nov 1, 2012 at 6:47 PM, Brian Schlining <bschlining@xxxxxxxxx> wrote:
> Hi All,
>
> I'm having an issue opening the file at
> http://data.nodc.noaa.gov/opendap/ghrsst/L4/GLOB/JPL_OUROCEAN/G1SST/2010/160/20100609-JPL_OUROCEAN-L4UHfnd-GLOB-v01-fv01_0-G1SST.nc.bz2'
>
> I get very a very different CDL when I open it locally vs when I open it via
> OPeNDAP (it's served by Hyrax). Most notably the variable attributes for
> lat, lon and time are 'transmorgified' into global attributes when read via
> OPeNDAP. Below are the different CDL's. If any knows of a workaround or has
> insight into what's going I'd appreciate hearing about it. Thanks
>
> When I open it with netcdf-java I get the following CDL:
>
> ===== WHAT I GET =====
>
> netcdf
> dods://data.nodc.noaa.gov/opendap/ghrsst/L4/GLOB/JPL_OUROCEAN/G1SST/2010/160/20100609-JPL_OUROCEAN-L4UHfnd-GLOB-v01-fv01_0-G1SST.nc.bz2
> {
> dimensions:
> time = 1;
> lat = 16000;
> lon = 36000;
> variables:
> float analysed_sst(time=1, lat=16000, lon=36000);
> :_CoordinateAxes = "time lat lon ";
> :long_name = "analysed sea surface temperature";
> :standard_name = "sea_surface_temperature";
> :type = "foundation";
> :units = "kelvin";
> byte mask(time=1, lat=16000, lon=36000);
> :_Unsigned = "true";
> :_CoordinateAxes = "time lat lon ";
> :long_name = "sea/land/lake/ice field composite mask";
> :_FillValue = -128B; // byte
> :flag_values = "1b, 2b, 4b, 8b";
> :flag_meanings = "sea land lake ice";
> :comment = "b0: 1=grid cell is open sea water012b1: 1=land is present
> in this grid cell012b2: 1=lake surface is present in this grid cell012b3:
> 1=sea ice is present in this grid cell012b4-b7: reserved for future grid
> mask data";
> float analysis_error(time=1, lat=16000, lon=36000);
> :_CoordinateAxes = "time lat lon ";
> :long_name = "estimated error standard deviation of analysed_sst";
> :units = "kelvin";
> int time(time=1);
> float lat(lat=16000);
> float lon(lon=36000);
>
> :time.units = "seconds since 1981-01-01 00:00:00";
> :time.long_name = "reference time of sst field";
> :time.standard_name = "time";
> :time.axis = "T";
> :time.calendar = "Gregorian";
> :lon.long_name = "longitude";
> :lon.standard_name = "longitude";
> :lon.axis = "X";
> :lon.units = "degrees_east";
> :lat.long_name = "latitude";
> :lat.standard_name = "latitude";
> :lat.axis = "Y";
> :lat.units = "degrees_north";
> :Conventions = "CF-1.0";
> :title = "G1SST, 1km blended SST";
> :DSD_entry_id = "JPL_OUROCEAN-L4UHfnd-GLOB-G1SST";
> :references = "A Blended Global 1-km Sea Surface Temperature Data Set for
> Research and Applications012by Yi Chao, Benyang Tang, Zhijin Li, Peggy Li,
> Quoc Vu";
> :institution = "Jet Propulsion Laboratory, The OurOcean Team";
> :contact = "yi.chao@xxxxxxxxxxxx";
> :GDS_version_id = "v1.0-rev1.7";
> :netcdf_version_id = "3.6.0";
> :creation_date = "2010-06-14 UTC";
> :product_version = "1.0";
> :history = "1km SST blended from 8 satellite observations";
> :spatial_resolution = "1 km";
> :source_data =
> "AMSRE,AVHRR,TMI,MODIS,MODIS,GOES,METOP,MTSAT,SEVIRI,AATSR,in-situ";
> :comment = "";
> :start_date = "2010-06-14 UTC";
> :start_time = "00:00:00 UTC";
> :stop_date = "2010-06-10 UTC";
> :stop_time = "00:00:00 UTC";
> :southernmost_latitude = -80.0f; // float
> :northernmost_latitude = 80.0f; // float
> :westernmost_longitude = -180.0f; // float
> :easternmost_longitude = 180.0f; // float
> :file_quality_index = 0; // int
> }
>
> ===== WHAT IT SHOULD BE =====
>
> netcdf
> /Users/brian/Downloads/20100609-JPL_OUROCEAN-L4UHfnd-GLOB-v01-fv01_0-G1SST.nc.bz2
> {
> dimensions:
> time = 1;
> lon = 36000;
> lat = 16000;
> variables:
> float analysed_sst(time=1, lat=16000, lon=36000);
> :long_name = "analysed sea surface temperature";
> :standard_name = "sea_surface_temperature";
> :type = "foundation";
> :units = "kelvin";
> byte mask(time=1, lat=16000, lon=36000);
> :long_name = "sea/land/lake/ice field composite mask";
> :_FillValue = -128B; // byte
> :flag_values = "1b, 2b, 4b, 8b";
> :flag_meanings = "sea land lake ice";
> :comment = "b0: 1=grid cell is open sea water\nb1: 1=land is present in
> this grid cell\nb2: 1=lake surface is present in this grid cell\nb3: 1=sea
> ice is present in this grid cell\nb4-b7: reserved for future grid mask
> data";
> float analysis_error(time=1, lat=16000, lon=36000);
> :long_name = "estimated error standard deviation of analysed_sst";
> :units = "kelvin";
> int time(time=1);
> :units = "seconds since 1981-01-01 00:00:00";
> :long_name = "reference time of sst field";
> :standard_name = "time";
> :axis = "T";
> :calendar = "Gregorian";
> :_CoordinateAxisType = "Time";
> float lon(lon=36000);
> :long_name = "longitude";
> :standard_name = "longitude";
> :axis = "X";
> :units = "degrees_east";
> :_CoordinateAxisType = "Lon";
> float lat(lat=16000);
> :long_name = "latitude";
> :standard_name = "latitude";
> :axis = "Y";
> :units = "degrees_north";
> :_CoordinateAxisType = "Lat";
>
> :Conventions = "CF-1.0";
> :title = "G1SST, 1km blended SST";
> :DSD_entry_id = "JPL_OUROCEAN-L4UHfnd-GLOB-G1SST";
> :references = "A Blended Global 1-km Sea Surface Temperature Data Set for
> Research and Applications\nby Yi Chao, Benyang Tang, Zhijin Li, Peggy Li,
> Quoc Vu";
> :institution = "Jet Propulsion Laboratory, The OurOcean Team";
> :contact = "yi.chao@xxxxxxxxxxxx";
> :GDS_version_id = "v1.0-rev1.7";
> :netcdf_version_id = "3.6.0";
> :creation_date = "2010-06-14 UTC";
> :product_version = "1.0";
> :history = "1km SST blended from 8 satellite observations";
> :spatial_resolution = "1 km";
> :source_data =
> "AMSRE,AVHRR,TMI,MODIS,MODIS,GOES,METOP,MTSAT,SEVIRI,AATSR,in-situ";
> :comment = "";
> :start_date = "2010-06-14 UTC";
> :start_time = "00:00:00 UTC";
> :stop_date = "2010-06-10 UTC";
> :stop_time = "00:00:00 UTC";
> :southernmost_latitude = -80.0f; // float
> :northernmost_latitude = 80.0f; // float
> :westernmost_longitude = -180.0f; // float
> :easternmost_longitude = 180.0f; // float
> :file_quality_index = 0; // int
> }
>
>
> --
> Brian Schlining
>
>
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--
Dr. Richard P. Signell (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598
