Format of AOD data for use with RRTMG and aer_opt = 2

[juliaandrys]

Hi there,

I am trying to run a regional climate simulation using wrf with NorESM data and I would like to incorporate aerosol data in the simulation. I understand that using by aer_opt = 2, with RRTMG I should be able to provide the aod5502d data to wrf using a netcdf-wrf supported file via auxiliary input stream 15.

I have created the necessary files however, wrf returns the following error:

NetCDF error: NetCDF: Attribute not found
NetCDF error in ext_ncd_get_dom_ti.code CHAR, line 83 Element TITLE
Error trying to read metadata
File name that is causing troubles = wrfaerinp_d01
You can try 1) ensure that the input file was created with WRF v4 pre-processors, or
2) use force_use_old_data=T in the time_control record of the namelist.input file
-------------- FATAL CALLED ---------------
FATAL CALLED FROM FILE: <stdin> LINE: 332
---- ERROR: The input file appears to be from a pre-v4 version of WRF initialization routines
-------------------------------------------

While I can incorporate the necessary elements into the metadata or apply the "force_use_old_data" namelist option, I wanted to ensure that I was on the right track with the way I am supplying this data to wrf before I tried these.

Should the auxiliary input stream 15 be used by real.exe? Is there a compilation step that I am missing to incorporate this data? Any additional information or advice you can provide on how I get wrf to read this data would be appreciated.

The relevant namelist options and metadata from my aux input file are below.

Thanks!

&time_control
auxinput15_inname = "wrfaerinp_d<domain>"
auxinput15_interval = 1440, 1440,
io_form_auxinput15 = 2,

&physics
mp_physics = 8, 8,
ra_lw_physics = 4, 4,
ra_sw_physics = 4, 4,
radt = 10, 10,
aer_opt = 2,
aer_aod550_opt = 2, 2
aer_angexp_opt = 3, 3
aer_ssa_opt = 3, 3
aer_asy_opt = 3, 3
aer_type = 1

netcdf wrfaerinp_d01 {
dimensions:
Time = UNLIMITED ; // (6 currently)
DateStrLen = 19 ;
west_east = 539 ;
south_north = 362 ;
variables:
float AOD5502D(Time, west_east, south_north) ;
AOD5502D:history = "2020-12-18T21:24:28Z altered by CMOR: Treated scalar dimension: \'wavelength\'. 2020-12-18T21:24:33Z altered by CMOR: Converted type from \'d\' to \'f\'." ;
AOD5502D:cell_measures = "area: areacella" ;
AOD5502D:cell_methods = "area: time: mean" ;
AOD5502Driginal_name = "DOD550" ;
AOD5502D:comment = "AOD from the ambient aerosols (i.e., includes aerosol water). Does not include AOD from stratospheric aerosols if these are prescribed but includes other possible background aerosol types. Needs a comment attribute \'wavelength: 550nm\'" ;
AOD5502D:missing_value = 1.e+20f ;
AOD5502D:_FillValue = 1.e+20f ;
AOD5502D:coordinates = "XLAT XLONG" ;
AOD5502D:units = "1" ;
AOD5502D:long_name = "Ambient Aerosol Optical Thickness at 550nm" ;
AOD5502D:standard_name = "atmosphere_optical_thickness_due_to_ambient_aerosol_particles" ;
char Times(Time, DateStrLen) ;

// global attributes:
:CDI = "Climate Data Interface version 1.9.10 (https://mpimet.mpg.de/cdi)" ;

 

[Ming Chen]

Hi,

The namelist options look fine and I don't think REAL program has anything to do with aod5502d. It is probably just a data issue. I wonder whether you include XLAT/XLONG information in your wrfaerinp datafile? Also, Which version of WRF are you running?

 

[sawadogowind]

I think there is a problem regarding the name of your input file "wrfaerinp_d<domain>"". Please try to rename your file name as "wrfaerinp_d.<domain>.<date>"" and try. This is an example of a file name that I use to run "CAMS_aerosols.d02.2019-04-10_18:00:00" then in the name list you need to that CAMS_aerosols.d02<domain>.<date> and it should be the exact date. Let me know the outcome

 

[juliaandrys]

Hi there,

Thanks for the responses to this. In the end I managed to get wrf to read the aerosol data by exactly mirroring the file format and variable attributes in the wrflowinp data files (see below). In particular, the "Field Type = 104" variable attribute seemed to be key to the data being successfully read. I did also have to set "force_use_old_data = .True." These tests were using WRF4.1

ncdump -h wrfaerinp_d01_1950-01-01.nc
netcdf wrfaerinp_d01_1950-01-01 {
dimensions:
Time = UNLIMITED ; // (7 currently)
DateStrLen = 19 ;
south_north = 337 ;
west_east = 513 ;
variables:
char Times(Time, DateStrLen) ;
double AOD5502D(Time, south_north, west_east) ;
AOD5502D:coordinates = "XLONG XLAT" ;
AOD5502D:stagger = " " ;
AOD5502D:MemoryOrder = "XY" ;
AOD5502D:units = "no_units" ;
AOD5502D:long_name = "aod from NorESM" ;
AOD5502D:FieldType = 104 ;
float XLAT(south_north, west_east) ;
XLAT:FieldType = 104 ;
XLAT:MemoryOrder = "XY " ;
XLAT:description = "LATITUDE, SOUTH IS NEGATIVE" ;
XLAT:units = "degree_north" ;
XLAT:stagger = "" ;
XLAT:coordinates = "XLONG XLAT" ;
float XLONG(south_north, west_east) ;
XLONG:FieldType = 104 ;
XLONG:MemoryOrder = "XY " ;
XLONG:description = "LONGITUDE, WEST IS NEGATIVE" ;
XLONG:units = "degree_east" ;
XLONG:stagger = "" ;
XLONG:coordinates = "XLONG XLAT" ;
float Time(Time) ;
Time:long_name = "synthesized time coordinate from Times(time)" ;
Time:units = "hours since 1950-01-01 00:00:00" ;
Time:_CoordinateAxisType = "Time" ;
Time:calendar = "noleap" ;

// global attributes:
:Title = "Aerosol Properties" ;
}