RRTMG scheme and ozone profile

[mauro_morichetti]

Hi all,

I am working on the effect of short lived climate forcers (SLCFs) to the radiation and energy balance, on simulation with semi-hemisferic domain over the Arctic.

I have done 3 simulations last one year (2018), with RRTMG scheme for both LW and SW radiation:

1- The first one is the control simulation: is WRF with no chem and climatological profiles for ozone (o3_input=2 and aer_opt=0 --> both default);

2- The second simulation is with MOZCART chemical scheme and same as before (o3_input=2 and aer_opt=0 --> both default);

3- The last one is identical to the previuos, but with one change: I have modified the code adding a new option for o3_input=3 in which the code reads the ozone profiles calculate online (and same default value for aer_opt=0).
The code added is the following (phys/module_radiation_dirver.F):

1679 !     Interpolating climatological ozone and aerosol to model time and levels
1680 !     Adapted from camrad code
1681 #if (EM_CORE==1)
1682      IF ( o3input .EQ. 2 .AND. id .EQ. 1 ) THEN
1683 #else
1684      IF ( o3input .EQ. 2 ) THEN
1685 #endif
1686 !       ! Find the current month (adapted from Cavallo)
1687 !       CALL cam_time_interp( ozmixm, pin, levsiz, date_str, &
1688 !                             ids , ide , jds , jde , kds , kde , &
1689 !                             ims , ime , jms , jme , kms , kme , &
1690 !                             its , ite , jts , jte , kts , kte )
1691 ! this is the CAM version
1692 ! interpolate to model time-step
1693         call ozn_time_int(julday,julian,ozmixm,ozmixt,levsiz,n_ozmixm,    &
1694                               ids , ide , jds , jde , kds , kde ,     &
1695                               ims , ime , jms , jme , kms , kme ,     &
1696                               its , ite , jts , jte , kts , kte )
1697 
1698 ! interpolate to model model levels
1699         call ozn_p_int(p ,pin, levsiz, ozmixt, o3rad, &
1700                               ids , ide , jds , jde , kds , kde ,     &
1701                               ims , ime , jms , jme , kms , kme ,     &
1702                               its , ite , jts , jte , kts , kte )
1703      ENDIF
1704 
1705 ! UMM --> use of ozone value calculate internally
1706 #if (WRF_CHEM == 1)
1707      IF ( o3input .EQ. 3 .AND. id .EQ. 1 ) THEN
1708      do i=its,ite
1709         do j= jts,jte
1710            do k=kts,kte
1711               o3rad(i,k,j)=chem(i,k,j,p_o3)*1.0E-6
1712            end do
1713         end do
1714      end do
1715      ENDIF
1716 #endif
1717 ! UMM --> use of ozone value calculate internally

The plot attached shows the monthly value of the area average of a energy balance at surface. As you can see the bigger gap is between values are from the first and second simulations, in particular in june.

My question is, why I have this difference between the first and second simulation? I mean, the RRTMG aerosol and ozone dependencies are both default value, so I would expected same values. How the chemistry scheme influences the radiation scheme?

Thanks in advance

Mauro

 

[jordanschnell]

Hi Mauro,

Will take a look at this. Can you attach your namelist (input and output)? Also, which version of WRF-Chem are you using?

Thanks.

Jordan

 

[mauro_morichetti]

Hi Jordan,

attached the namelist.input.

Unfortunately, I have not the output nameless saved.

CTRL --> only WRF (with o3_input=2 and aer_opt=0)
RUN1 --> WRF-CHEM (with o3_input=2 and aer_opt=0)
RUN2 --> WRF-CHEM (with o3_input=3 and aer_opt=0)

Thanks in advance.

 

[jordanschnell]

Hi Mauro,

You have aer_ra_feedback = 1, so while ozone impacts on radiation will be the same between CTRL and RUN1, you'll have the impacts from your prognostic aerosols. AER_OPT = 0 does NOT turn off impacts from prognostic aerosols, it just tells the model not to input a climatology.

A side note, I noticed a couple typos in your namelist where you have "ture" instead of "true"

Jordan

 

[mauro_morichetti]

Hi Jordan,

Ok, now it is clearer.

Thanks