[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[IDV #HJB-447677]: IDV and netcdf calendar types?



> Hi Yuan,
> 
> Thanks for your reply. I uploaded a sample NARCCAP file to the idvupload
> site.
> 
> This particular file has a "noleap" calendar (see below). As I
> mentioned, depending how far out from "1968-01-01 00:00:0.0" (the
> beginning of the dataset) you are, the days are a few "off" from what we
> are expecting from what we get when use NCL to read it data. Since NCL
> is reading the calendar info in, I started to wonder if the IDV
> timestamps are off because it is assuming everything is a "true"
> calendar, with leap years and all?
> 
> Thanks for any info you can provide!
> 
> Kelly
> 
> 

Kelly,
    I checked with other developer and find out that there is no support for 
the "noleap" calendar for the current release. This type of calendar has been 
added to the netCDF Java 4.3 release, but the IDV still run the netCDF Java 4.2 
release. We are planning to move to 4.3 release in the near future. I will keep 
you post.


Yuan
> 
> 
> 
> 
> > [kmahoney@intb Debugging]$ ncdump -h huss_RCM3_cgcm3_1991010103.nc
> > netcdf huss_RCM3_cgcm3_1991010103 {
> > dimensions:
> >         time = UNLIMITED ; // (14600 currently)
> >         yc = 104 ;
> >         xc = 134 ;
> > variables:
> >         float huss(time, yc, xc) ;
> >                 huss:grid_mapping = "Transverse_Mercator" ;
> >                 huss:standard_name = "specific_humidity" ;
> >                 huss:long_name = "Surface_Specific_Humidity" ;
> >                 huss:units = "kg kg-1" ;
> >                 huss:coordinates = "lon lat" ;
> >                 huss:missing_value = 1.e+20f ;
> >                 huss:original_name = "QA" ;
> >                 huss:original_units = "kg kg-1" ;
> >                 huss:_FillValue = 1.e+20f ;
> >         double lat(yc, xc) ;
> >                 lat:units = "degrees_north" ;
> >                 lat:long_name = "latitude" ;
> >                 lat:standard_name = "latitude" ;
> >                 lat:axis = "Y" ;
> >         double lon(yc, xc) ;
> >                 lon:units = "degrees_east" ;
> >                 lon:long_name = "longitude" ;
> >                 lon:standard_name = "longitude" ;
> >                 lon:axis = "X" ;
> >         double time(time) ;
> >                 time:standard_name = "time" ;
> >                 time:long_name = "time" ;
> >                 time:axis = "T" ;
> >                 time:units = "days since 1968-01-01 00:00:0.0" ;
> >                 time:calendar = "noleap" ;
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> On 1/23/2012 8:18 AM, Unidata IDV Support wrote:
> >> Hi,
> >>
> >> I am wondering if IDV recognizes different calendar types in netcdf files?
> >>
> >> I've been using it to view a lot of NCAR NARCCAP regional climate model
> >> data, which uses an array of calendar types.
> > Kelly,
> >      I am not very sure about the support of different calendar types in 
> > the IDV, can you upload a sample file:
> >
> >     http://motherlode.ucar.edu/repository/alias/idvupload
> >
> >
> > Yuan
> >> I'm noticing that certain fields seem to be off by several days, and I
> >> wonder if that's because IDV doesn't know about "no_leap" types of
> >> calendars?
> >>
> >> I see that the information about the calendar is indeed read in by IDV
> >> as it is listed in the metadata, but now I'm realizing that just because
> >> it is read in doesn't necessarily mean it is being used.
> >>
> >> Any insight on this would be greatly appreciated -- thanks very much!
> >>
> >> Kelly Mahoney
> >>
> >>
> >>
> >>
> >
> > Ticket Details
> > ===================
> > Ticket ID: HJB-447677
> > Department: Support IDV
> > Priority: Normal
> > Status: Open
> >
> 
> 


Ticket Details
===================
Ticket ID: HJB-447677
Department: Support IDV
Priority: Normal
Status: Closed