ERROR: lnd_import ERROR: Longwave down sent from the atmosphere model is negative or zero

[Chiru]

Hi everyone,
I am trying to run a CLM5 simulation with ERA5 land-atmosphere forcing data at 01-degree spatial resolution. For these, I created a case using the compset below 2000_DATM%GSWP3v1_CLM50%SP_SICE_SOCN_MOSART_SGLC_SWAV_SIAC_SESP.

However, my simulation fails after a few minutes with an ERROR: lnd_import ERROR: Longwave down sent from the atmosphere model is negative or zero.

Help me in this regard.

 

[Chiru]

PFA

 

[oleson]

There is zero or negative downward longwave radiation in your atm forcing file within your domain. First check your forcing files.

 

[Chiru]

Dear @oleson,
Thank you for your quick reply.

You are right My atmospheric forcing data has a fill value of -32767s. So I replaced the Missvalue/Fill value as 1.e+36 and ran the simulation however, this time I got the an error: as shown below

urban net longwave radiation balance error -1.475739525896764E+020
clm model is stopping
calling getglobalwrite with decomp_index= 136032 and clmlevel= landunit
local landunit index = 136032
global landunit index = 30301
global gridcell index = 10164
gridcell longitude = 72.8500000000000
gridcell latitude = 19.0500000000000
landunit type = 7
ENDRUN:
ERROR: ERROR in UrbanRadiationMod.F90 at line 699
urban net longwave radiation balance error -1.475739525896764E+020
clm model is stopping
calling getglobalwrite with decomp_index= 112823 and clmlevel= landunit
local landunit index = 112823
global landunit index = 29791
global gridcell index = 9994
gridcell longitude = 72.8500000000000
gridcell latitude = 18.9500000000000
landunit type = 7
ENDRUN:
ERROR: ERROR in UrbanRadiationMod.F90 at line 699
urban net longwave radiation balance error -1.475739525896764E+020
clm model is stopping
calling getglobalwrite with decomp_index= 124287 and clmlevel= landunit
local landunit index = 124287
global landunit index = 10338
global gridcell index = 3598
gridcell longitude = 80.2500000000000
gridcell latitude = 13.0500000000000
landunit type = 7
ENDRUN:

PFA.

This changing atmospheric forcing data is new to me. As for my understanding, I gave

Precipitation in mm/sec in user_datm.streams.txt.CLMGSWP3v1.Precip,

Surface solar radiation downwards (ssrd) (short wave) in W/m2 in user_datm.streams.txt.CLMGSWP3v1.Solar,

and 2m temperature (Kelvin), 2m dewpoint temperature (Kelvin), surface pressure (Pa), avg wind (m/s) (obtained from the 10m u and v wind components), and surface solar radiation downwards (strd) (W/m2) (long wave) in user_datm.streams.txt.CLMGSWP3v1.TPQW stream files.

The atmospheric forcing data is obtained from the ERA5-Land hourly data from 1950 to present.

 

[Chiru]

PFA

 

[Chiru]

I am sharing a link to sample of my atmospheric forcing data please find it https://csciitd-my.sharepoint.com/:...VElBzBhzZMn7oBvWP3rbNrB9fkbR4-z0OGmQ?e=ykJQtr

Surface solar radiation downwards (ssrd) (short wave) (in W/m2), a variable that comprises both direct and diffuse solar radiation (given in user_datm.streams.txt.CLMGSWP3v1.Solar),

Surface thermal radiation downwards (strd) (W/m2) (long wave) is the amount of thermal (also known as longwave or terrestrial) radiation emitted by the atmosphere and clouds that reaches the Earth's surface (given in user_datm.streams.txt.CLMGSWP3v1.TPQW stream files).

Kindly let me know what I am missing in my forcing data and how to overcome this error.

 

[oleson]

Replacing the negative fill value with a Missvalue/Fill value as 1.e+36 won't do any good as the datm will still use that value. That's likely why you are getting such a large longwave error (-1.475739525896764E+020). I would check the mask in the mesh file if you are using nuopc or the mask in the domain file if you are using mct to make sure it is consistent with valid forcing data.