Use all vertical levels in FNL data

[Naser]

Dear all

Hi,

As I saw on the UCAR website, the maximum vertical level of FNL data is 87. "Number of vertical levels/layers: 87". I wonder how I can use all these levels in my metgrid data.
You can see my namelist.wps in below:

&share
wrf_core = 'ARW',
max_dom = 2,
start_date = '2023-05-01_00:00:00','2023-05-01_00:00:00','2023-05-01_00:00:00',
end_date = '2023-05-05_00:00:00','2023-05-05_00:00:00','2023-05-05_00:00:00'
interval_seconds = 21600
io_form_geogrid = 2,
/

&geogrid
parent_id = 1, 1, 2,
parent_grid_ratio = 1, 5, 5,
i_parent_start = 1, 21, 10,
j_parent_start = 1, 21, 25,
e_we = 50, 51, 126,
e_sn = 50, 51, 126,
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!! IMPORTANT NOTE !!!!!!!!!!!!!!!!!!!!!!!!!!!!
! The default datasets used to produce the MAXSNOALB and ALBEDO12M
! fields have changed in WPS v4.0. These fields are now interpolated
! from MODIS-based datasets.
!
! To match the output given by the default namelist.wps in WPS v3.9.1,
! the following setting for geog_data_res may be used:
!
! geog_data_res = 'maxsnowalb_ncep+albedo_ncep+default', 'maxsnowalb_ncep+albedo_ncep+default',
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!! IMPORTANT NOTE !!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
geog_data_res = 'default','default','default'
dx = 500,
dy = 500,
map_proj = 'lambert',
ref_lat = 37.5,
ref_lon = 127.3,
truelat1 = 30.0,
truelat2 = 60.0,
stand_lon = 126.0,
geog_data_path = '/home/unist/naser/_data/MAP/'
/

! geog_data_res = '10m','2m'
! geog_data_res = 'usgs_lakes+default','usgs_lakes+default',


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

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

&mod_levs
press_pa = 201300 , 200100 , 100000,
95000 , 90000 ,
85000 , 80000 ,
75000 , 70000 ,
65000 , 60000 ,
55000 , 50000 ,
45000 , 40000 ,
35000 , 30000 ,
25000 , 20000 ,
15000 , 10000 ,
5000 , 1000
/

 

[Ming Chen]

How many levels did you get after running metgrid.exe?

 

[Naser]

Dear Chen,
Hi

After using ncdump -h, I've got "num_metgrid_levels = 34"

 

[Ming Chen]

Wold you please point me to the FNL website that states "Number of vertical levels/layers: 87"?

I looked at the NCAR FNL website NCAR RDA Dataset d083003, which seems different to the website you mentioned.

 

[Naser]

Wold you please point me to the FNL website that states "Number of vertical levels/layers: 87"?

I looked at the NCAR FNL website NCAR RDA Dataset d083003, which seems different to the website you mentioned.

Dear Chen,
Please see this address:
NSF NCAR Research Data Archive


Best,
Naser

 

[Naser]

Wold you please point me to the FNL website that states "Number of vertical levels/layers: 87"?

I looked at the NCAR FNL website NCAR RDA Dataset d083003, which seems different to the website you mentioned.

Dear Chen,

1) I always download FNL data from this website:
NCEP FNL Operational Model Global Tropospheric Analyses, continuing from July 1999
Files name: fnl_20120529_00_00.grib2

2) But your recommended website is this:
NCEP GDAS/FNL 0.25 Degree Global Tropospheric Analyses and Forecast Grids
Files name: gdas1.fnl0p25.2024010100.f00.grib2

Are the most significant differences related to resolution and purpose (coarse versus fine)?

1)1*1
2)0.25*0.25

Best,
Naser

 

[Ming Chen]

Naser,
Please see my answers below:

Dear Chen,
1) I always download FNL data from this website:
NCEP FNL Operational Model Global Tropospheric Analyses, continuing from July 1999
Files name: fnl_20120529_00_00.grib2

Somehow I cannot access the website you posted above. It shows that "Page not found"

2) But your recommended website is this:
NCEP GDAS/FNL 0.25 Degree Global Tropospheric Analyses and Forecast Grids
Files name: gdas1.fnl0p25.2024010100.f00.grib2

This is the official website maintained by NCAR RDA for FNL products. Please download files from this website.

Are the most significant differences related to resolution and purpose (coarse versus fine)?

I am not sure. We always use data from NCAR RDA.

1)1*1
2)0.25*0.25

Best,
Naser

 

[Naser]

Naser,
Please see my answers below:


Somehow I cannot access the website you posted above. It shows that "Page not found"


This is the official website maintained by NCAR RDA for FNL products. Please download files from this website.

I am not sure. We always use data from NCAR RDA.

Dear Chen,

Thank you.

I still have a question about the vertical levels. Could you check my attached figures to confirm if there are 87 vertical levels?

NSF NCAR Research Data Archive
Thank you,
Naser

 

[Ming Chen]

It is weird that I cannot access the data. It. always show that "PAGE NOT FOUND"
One thing for sure is that, this is not the website we use to obtain GFS data. Why do you insist on staying with this website to obtain data?

 

[Naser]

It is weird that I cannot access the data. It. always show that "PAGE NOT FOUND"
One thing for sure is that, this is not the website we use to obtain GFS data. Why do you insist on staying with this website to obtain data?

Dear Chen,

I’m not sure why this is happening, but the website is currently working fine for me. I just wanted to point out the detail "Number of vertical levels/layers: 87," which I noticed in the figures attached above.

Regarding the data usage, I have followed your advice and used the recommended website as you suggested, rather than any others.

2) But your recommended website is this:
NCEP GDAS/FNL 0.25 Degree Global Tropospheric Analyses and Forecast Grids
Files name: gdas1.fnl0p25.2024010100.f00.grib2

Thank you,
Best,
Naser