Hi,
I think you can get the grid you want using the /ORDER qualifier as already suggested. Here is the documentation link for the /ORDER qualifier. http://ferret.pmel.noaa.gov/Ferret/documentation/users-guide/commands-reference/SET#_VPINDEXENTRY_1594
The order in the grid of the variables,
float air_temperature(time, longitude, latitude)
is not the standard order which would be (time, latitude, longitude).
Ferret follows the COARDS and CF standards for netCDF files.
http://ferret.pmel.noaa.gov/Ferret/documentation/coards-netcdf-conventions
The CF conventions, http://cf-convention.github.io/1.6.html#dimensions discusses this as well. This ordering is not required in CF, and Ferret can open the file and read the data, but the default ordering is required Ferret to get plots and other operations right.
In addition, if the variables lon, lat, and time are intended as coordinate variables, then their names should share the names of the dimensions. It looks like this is the case with time in your file, but not longitude and latitude. If one were writing the file, and did it this way:
float longitude(longitude) ;
lon:long_name = "Longitude" ;
lon:standard_name = "longitude" ;
lon:units = "degrees_east" ;
lon:valid_range = 0.f, 360.f ;
float latitude(latitude) ;
etc.
then Ferret would be able to automatically label plots with degrees, and do all the other operations it knows how to do with longitude/latitude coordinates. We can use Ferret to define axes using the 1-D lon, lat variables in the file.
define axis/x/units="`lon,return=units`"/title="`lon,return=title`" longitude = lonand you should be good to go.
define axis/y/units="`lat,return=units`"/title="`lat,return=title`" latitude = lat
Ansley
On 4/8/2014 6:51 AM, Ge Peng - NOAA Affiliate wrote:
Does ferret assume by default the order of dimensions of input netCDF files as lon, lat, time without height?
I have a file with array dimensions defined as lat, lon, and time (see the attached ncdump file) and the dimensions loaded into ferret are as follows:
sho datacurrently SET data sets:1> ./SEAFLUXNN_ATMOS_CDR_V01R00_D19880101.nc (default)name title I J K LAIR_TEMPERATURENOAA CDR of near-surface air temp 1:720 1:1440 ... 1:8SPECIFIC_HUMIDITYNOAA FCDR of near-surface speci 1:720 1:1440 ... 1:8WIND_SPEEDNOAA FCDR of near-surface wind 1:720 1:1440 ... 1:8LON Longitude 1:1440 ... ... ...LAT Latitude 1:720 ... ... ...LAND_MASKLand mask 1:720 1:1440 ... ...ICE_MASK Ice mask 1:720 1:1440 ... ...COAST_MASKCoastal mask 1:720 1:1440 ... ...
--Do I need to define those array dimension orders as lon, lat, and time in order to load and display in ferret properly without redefining a new grid?
Thanks,
--- Peng
Ge Peng, Ph.D
Research Scholar
Cooperative Institute for Climate and Satellites NC
North Carolina State University
NOAA's National Climatic Data Center
151 Patton Ave, Asheville, NC 28801
ge.peng@xxxxxxxx
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