[gradsusr] Problem when plotting daily means from NetCDF

Daniel Klaus Daniel.Klaus at awi.de
Thu Sep 16 06:45:31 EDT 2010

Dear all,    I have a strange problem with GrADS:    I use a NetCDF file including daily averaged variables (fields). The  file contains all required dimensions x, y, z, time=UNLIMITTED;//(397  currently), where the time coordinate varies from 1 to 397, which  corresponds to a time range of 13 months starting at the 1st of August  2007. I open the file with "xdfopen" using a descriptor file similar to:  ========================================================  DSET ^file_avg.nc  TITLE 'Model daily means of prognostic variables'  UNDEF -2.56E33  XDEF lon  YDEF lat  ZDEF lev  TDEF time 397 LINEAR 0Z01Aug2007 1DY  =========================================================    Lon, lat and lev (x,y,z) as well as the variables (Temperature T,  specific humidity Q, ...) are well defined directly in "file_avg.nc" and  the file can be read without any problem. In principle, all seems to be  ok, because creating graphics with respect to a certain time step (day  mean vertical profile) works normally. For instance a temperature  profile with following settings:  -------------------------------------  X is fixed     Lon = 1  X = 1  Y is fixed     Lat = 1  Y = 1  Z is varying   Lev = 1012.05 to 0.1   Z = 1 to 60  T is fixed     Time = 00Z11SEP2007  T = 42  ga-> d T  -------------------------------------    is drawed correctly but displaying a time-height cross section (contour  plot) of temperature (i.e. using a time interval) e.g. with settings  according to:  -------------------------------------  X is fixed     Lon = 1  X = 1  Y is fixed     Lat = 1  Y = 1  Z is varying   Lev = 1012.05 to 0.1   Z = 1 to 60  T is varying   Time = 00Z01AUG2007 to 00Z16FEB2008  T = 1 to 200  ga-> d T  -------------------------------------    fails. Although the time axis is drawed correctly, something stranged is  displayed in the graphic window that is really nonsense. Besides I get  the message:  ------------------------------  Contouring: -0 to 2e+07 interval 2e+06  ------------------------------    Now, I assume that it is a GrADS problem, because "ncview" plots the  whole 397 day period and single days as well. GrADS has obviously a  problem with the time coordinate, although I redefined it within the  descriptor file.    Has anybody an idea, what have I done wrong and what to do?      best wishes,  Daniel Klaus      _______________________________________________________  Daniel Klaus  Dipl.-Physiker (graduate physicist), PhD Student  Alfred Wegener Institute for Polar and Marine Research  Research Unit Potsdam  -Atmospheric Circulations-  Telegrafenberg A43-105  14473 Potsdam  Germany    phone: +49(331)288-2202  email: Daniel.Klaus at awi.de   
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