North pole POLE_LAT in geogrid file in Antarctica

[tpletzer]

Hi,

I used the following namelist.wps file and specified all negative latitudes, however when I ran ./geogrid.exe the log now has a POLE_LAT specified as the north pole. How can I fix this?
namelist.wps:

&share
wrf_core = 'ARW',
max_dom = 1,
start_date = '2021-01-14_00:00:00',
end_date = '2021-01-14_12:00:00',
interval_seconds = 21600,
io_form_geogrid = 2,
debug_level = 0,
/

&geogrid
parent_id = 1,
parent_grid_ratio = 1,
i_parent_start = 1,
j_parent_start = 1,
e_we = 300,
e_sn = 300,
geog_data_res = 'greenfrac_fpar_modis+default',
dx = 200,
dy = 200,
map_proj = 'polar',
ref_lat = -77.671,
ref_lon = 162.681,
truelat1 = -77.671,
truelat2 = -90,
stand_lon = 162.681,
geog_data_path = '~/WPS_GEOG',
ref_x = 150.0,
ref_y = 150.0,
/

&ungrib
out_format = 'WPS',
prefix = 'FILE',
/

&metgrid
fg_name = 'FILE',
io_form_metgrid = 2,
/

geogrid.log:
2022-04-03 10:24:09.720 --- *** Starting program geogrid.exe ***
2022-04-03 10:24:09.721 --- Using the following namelist variables:
2022-04-03 10:24:09.721 --- &SHARE
2022-04-03 10:24:09.721 --- WRF_CORE = ARW
2022-04-03 10:24:09.721 --- MAX_DOM = 1
2022-04-03 10:24:09.721 --- START_YEAR = 0
2022-04-03 10:24:09.721 --- START_MONTH = 0
2022-04-03 10:24:09.721 --- START_DAY = 0
2022-04-03 10:24:09.721 --- START_HOUR = 0
2022-04-03 10:24:09.721 --- START_MINUTE = 0
2022-04-03 10:24:09.721 --- START_SECOND = 0
2022-04-03 10:24:09.721 --- END_YEAR = 0
2022-04-03 10:24:09.721 --- END_MONTH = 0
2022-04-03 10:24:09.721 --- END_DAY = 0
2022-04-03 10:24:09.721 --- END_HOUR = 0
2022-04-03 10:24:09.721 --- END_MINUTE = 0
2022-04-03 10:24:09.721 --- END_SECOND = 0
2022-04-03 10:24:09.721 --- START_DATE = 2021-01-14_00:00:00
2022-04-03 10:24:09.721 --- END_DATE = 2021-01-14_12:00:00
2022-04-03 10:24:09.721 --- INTERVAL_SECONDS = 21600
2022-04-03 10:24:09.721 --- IO_FORM_GEOGRID = 2
2022-04-03 10:24:09.721 --- OPT_OUTPUT_FROM_GEOGRID_PATH = ./
2022-04-03 10:24:09.721 --- SUBGRID_RATIO_X = 1
2022-04-03 10:24:09.721 --- SUBGRID_RATIO_Y = 1
2022-04-03 10:24:09.722 --- DEBUG_LEVEL = 0
2022-04-03 10:24:09.722 --- ACTIVE_GRID = .TRUE.
2022-04-03 10:24:09.722 --- NOCOLONS = .FALSE.
2022-04-03 10:24:09.722 --- /
2022-04-03 10:24:09.722 --- &GEOGRID
2022-04-03 10:24:09.722 --- PARENT_ID = 1
2022-04-03 10:24:09.722 --- PARENT_GRID_RATIO = 1
2022-04-03 10:24:09.722 --- I_PARENT_START = 1
2022-04-03 10:24:09.722 --- J_PARENT_START = 1
2022-04-03 10:24:09.722 --- S_WE = 1
2022-04-03 10:24:09.722 --- E_WE = 300
2022-04-03 10:24:09.722 --- S_SN = 1
2022-04-03 10:24:09.722 --- E_SN = 300
2022-04-03 10:24:09.722 --- GEOG_DATA_RES = greenfrac_fpar_modis+default
2022-04-03 10:24:09.722 --- DX = 200.000000
2022-04-03 10:24:09.722 --- DY = 200.000000
2022-04-03 10:24:09.722 --- MAP_PROJ = polar
2022-04-03 10:24:09.722 --- POLE_LAT = 90.000000
2022-04-03 10:24:09.722 --- POLE_LON = 0.000000
2022-04-03 10:24:09.722 --- REF_LAT = -77.670998
2022-04-03 10:24:09.722 --- REF_LON = 162.681000
2022-04-03 10:24:09.722 --- REF_X = 150.000000
2022-04-03 10:24:09.722 --- REF_Y = 150.000000
2022-04-03 10:24:09.722 --- TRUELAT1 = -77.670998
2022-04-03 10:24:09.722 --- TRUELAT2 = -90.000000
2022-04-03 10:24:09.722 --- STAND_LON = 162.681000
2022-04-03 10:24:09.722 --- GEOG_DATA_PATH = ~/WPS_GEOG
2022-04-03 10:24:09.722 --- OPT_GEOGRID_TBL_PATH = geogrid/
2022-04-03 10:24:09.722 --- /

Any help is appreciated
Cheers

 

[Ming Chen]

Please change your namelist.wps as follows:
ref_lat = -90.0
ref_lon = 162.681,
truelat1 = -77.671,
stand_lon = 162.681,

Then try again. Please let me know whether you can get correct result.

 

[mgduda]

The 'pole_lat' parameter is only used by the 'latlon' projection and is ignored when using a polar stereographic ('polar') projection.

From the Description of the Namelist Variables section of Chapter 3 of the ARW User's Guide:

20. POLE_LAT : For the latitude-longitude projection for ARW, the latitude of the North Pole with respect to the computational latitude-longitude grid in which -90.0° latitude is at the bottom of a global domain, 90.0° latitude is at the top, and 180.0° longitude is at the center. Default value is 90.0.

If you'd like, you can explicitly set 'pole_lat = -90.0' (or whatever value you like) in your namelist.wps file, but doing so will have no impact.