I have a 33-yr dataset of daily swath files in one dimension (time, l=1:NL).
NL varies with each daily file. Time, lat and lon are not on a fixed and evenly spaced grid.
The following is from ncdump -h of one of such files:
netcdf T2m.N14.Y99.D365 {
dimensions:
time = UNLIMITED ; // (137263 currently)
variables:
float t2m(time) ;
t2m:long_name = "temperature at 2 m" ;
t2m:units = "C" ;
t2m:coordinates = "lon lat" ;
float lat(time) ;
lat:units = "degrees_north" ;
lat:valid_range = -90., 90. ;
float lon(time) ;
lon:units = "degrees_east" ;
lon:valid_range = 0., 360. ;
float time(time) ;
time:units = "seconds" ;
time:long_name = "seconds from 0 UTC" ;
}
The following is the output of show data in ferret:
yes? show data
currently SET data sets:
name title I J K L
T2M temperature at 2 m ... ... ... 1:137263
LAT ... ... ... 1:137263
LON ... ... ... 1:137263
I would like to use a .desr file to load all nc files or some nc files for a given time period and create a mask to isolate T2M using a range of lon, lat, and time. for example, 140 < lon < 170; 65 < lat < 90; 3600 < time < 4800.
Is there a way to obtain the dimension of the records (time dimension in this case) to create a .desr file without having to open all nc files first?
I am not used to working with data this kind. Any suggestion/tips on ways to load and work with them are appreciated. It is preferred to do so without re-gridding unless I have no other way.
Thanks,
--- Peng