12 November 2009, eaton

Processing to create 1850 climatology dataset from
the decadal avg data provided by Jean-Francois Lamarque.

The 1855 climatology will be used for year 1850.

The details follow:

1. Convert decadal avg files from r8 to r4 data, and remove the variable T.
   Previously we removed PS as well, but it turns out that the interpolation scheme
   uses PS if it is present and that results in a more accurate vertical
   interpolation to the model grid.

   This step is done using the cam interpolation routine from tools/interpic_new/.

% /blhome/eaton/bin/interpic -e T -p 4 -t /fis/cgd/cseg/csm/inputdata/atm/cam/inic/fv/camchemi_0012-01-01_1.9x2.5_L26_c081104.nc /ptmp/lamar/IPCC_AR5/Climatologies_20091110/aero_1.9x2.5_L26_1850-1859.nc aero_1.9x2.5_L26_1850-1859.r4.nc 
% mv aero_1.9x2.5_L26_1850-1859.r4.nc aero_1.9x2.5_L26_1850clim_c091112.nc

2. Fix the time/date variables.  Here is the .cdl file that contains the 
   times and dates.

netcdf date_time_1850clim {
dimensions:
	time = UNLIMITED ; // (37 currently)
variables:
	int date(time) ;
		date:long_name = "date" ;
		date:format = "YYYYMMDD" ;
	double time(time) ;
		time:long_name = "time" ;
		time:units = "days since 1850-01-01 00:00" ;
		time:calendar = "noleap" ;

data:

 date = 
    18500115, 18500215, 18500315, 18500415, 18500515, 18500615, 18500715, 18500815, 18500915, 18501015, 18501115, 18501215 ;

 time = 
    14, 45, 73, 104, 134, 165, 195, 226, 257, 287, 318, 348 ;
}

3. Use ncgen to convert the cdl file above to netcdf.  Then
   extract the time,date variables from this file and use them to overwrite
   the time,date variables in the file containing the concatenated time
   samples.

% ncgen -b date_time_1850clim.cdl
% ncks --append -v date,time date_time_1850clim.nc aero_1.9x2.5_L26_1850clim_c091112.nc

5. Use ncwa to zonally avg the final dataset and take a look with ncview.  Looks OK.

% ncwa -a lon aero_1.9x2.5_L26_1850clim_c091112.nc aero_1.9x2.5_L26_1850clim_za_c091112.nc

6. Move to final location:

% mv aero_1.9x2.5_L26_1850clim_c091112.nc \
  /fis/cgd/cseg/csm/inputdata/atm/cam/chem/trop_mozart_aero/aero