Hi Fan,
Thank you for the report. I can replicate the behavior with Ferret
statements.
yes? define
axis/t="1-jan-2006:12":"5-jan-2006:12":86400/units=seconds/t0=1-jan-1970/calendar=julian
time5
yes? define axis/x=100w:100e:5/units=degrees_east xax
yes? let tvar = L[gt=time5]
yes? let xtvar = tvar + sin(x[gx=xax]/40)
yes? shade xtvar
The time axis I define here is a bit different from the one in your
file. The one in my example has the time coordinates in the middle
of the timestep and yours is at one edge. Both are legal definitions
and both show this same behavior. The fact that we have a Julian
calendar does not affect things. We'll look into this.
Ansley
On 2/19/2014 9:44 AM, Fan Fang wrote:
I am trying to use Ferret to do a Hovmoller plot with a simple
netCDF file.
Wonder why the
Hovmoller plot came out slightly shifted upward (by ~6
hours; attached). The header of the CDL is below. I can send the
netcdf file also if needed but thought the problem could be just
some mistake using Ferret.
Thanks.
-Fan
> ferret/bin/ferret
NOAA/PMEL TMAP
FERRET v6.85
Linux 2.6.32-358.23.2.el6.x86_64 64-bit - 11/12/13
19-Feb-14 12:28
yes? use test.nc
yes? show data
currently SET data sets:
1> ./test.nc (default)
name title I J
K L M N
OMAERUVD_003_FINALAEROSOLEXTOPTICALDEPTH388
Aerosol Optical Depth 388 nm (n 1:360 ...
... 1:5 ... ...
yes? shade OMAERUVD_003_FINALAEROSOLEXTOPTICALDEPTH388
The values of the time and 'time_bnds' variables are:
time = 1136073600, 1136160000, 1136246400, 1136332800, 1136419200
;
time_bnds =
1136073600, 1136160000,
1136160000, 1136246400,
1136246400, 1136332800,
1136332800, 1136419200,
1136419200, 1136505600 ;
netcdf test {
dimensions:
bnds = 2 ;
time = UNLIMITED ; // (5 currently)
lon = 360 ;
variables:
int time_bnds(time, bnds) ;
float OMAERUVd_003_FinalAerosolExtOpticalDepth388(time, lon) ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:_FillValue =
-1.267651e+30f ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:units = "1" ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:title = "Final
Aerosol Extinction Optical Depth at 388 nm" ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:UniqueFieldDefinition
= "OMI-Specific" ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:missing_value
= -1.267651e+30f ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:origname =
"FinalAerosolExtOpticalDepth388" ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:fullnamepath =
"/HDFEOS/GRIDS/Aerosol NearUV Grid/Data
Fields/FinalAerosolExtOpticalDepth388" ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:orig_dimname_list =
"XDim " ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:standard_name
= "finalaerosolextopticaldepth388" ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:quantity_type
= "Total Aerosol Optical Depth" ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:product_short_name =
"OMAERUVd" ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:product_version =
"003" ;
OMAERUVd_003_FinalAerosolExtOpticalDepth388:long_name =
"Aerosol Optical Depth 388 nm (near-UV), OMI, 1 x 1 deg." ;
float lon(lon) ;
lon:standard_name = "longitude" ;
lon:units = "degrees_east" ;
lon:long_name = "Longitude" ;
int time(time) ;
time:standard_name = "time" ;
time:units = "seconds since 1970-01-01 00:00:00" ;
time:bounds = "time_bnds" ;
time:calendar = "JULIAN" ;
// global attributes:
:Conventions = "CF-1.4" ;
:start_time = "2006-01-01T00:00:00Z" ;
:end_time = "2006-01-05T23:59:59Z" ;
:temporal_resolution = "daily" ;
:nco_openmp_thread_number = 1 ;
:NCO = "4.3.1" ;
:plot_hint_title = "Latitude-Averaged Hovmoller ( 90S -
90N )" ;
:plot_hint_subtitle = "daily 1 x 1 deg. Aerosol Optical
Depth 388 nm (near-UV), OMI, 1 x 1 deg. [OMAERUVd v3]" ;
:plot_hint_x_axis_label = "Longitude" ;
:plot_hint_y_axis_label = "Time" ;
:plot_hint_caption = "Selected latitude range was 90S -
90N. The variable Aerosol Optical Depth 388 nm (near-UV), OMI, 1 x
1 deg. [OMAERUVd v3] has a limited data extent of 90S - 90N. The
longitude range in the title reflects the data extent of the
subsetted granules that went into making this result." ;
}
|