Hello, everyone, I am planning to run some cases to simulate the stratospheric aerosol injection (for example, Injecting SO2 into the stratospheric) using CESM 1.2.2. I'm trying to run CESM1.2.2(WACCM5) now, and have established the corresponding case (compset：B1850W5CN), but I don't know how to add the forced data. After watching some posts in the discussion forum, I learned that, CAM5 can use prescribed_volcearo_nl to add and adjust volcanic compulsion, however, I still don't know how to add volcanic forcing in WACCM5(CESM1.2.2).If anyone knows, can you tell me in detail? It's very important to me. Thank you very much.
How to add volcanic forcing data in CESM1.2.2-WACCM5
- Thread starter GXJ
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Is there a reason why you aren't using WACCM6? WACCM5 was an intermediate stage. Although we do have this one WACCM5 compset in the release, I don't remember exactly why we released it, and I might need to do some investigating to understand what is in it.
In WACCM6, stratospheric aerosol injections are handled via the external forcing. In the namelist, this is a list of emissions files and corresponding species in the ext_frc_specifier. For example, below is the default list for the BWHIST compset.
If you want to do stratospheric SO2 injections, you would create a similar emissions file describing the region where you want SO2 emitted. You can also add a scale factor in front of the path to the emissions file, such as "4*" to multiply the emission rates by a factor of 4.
ext_frc_specifier = 'bc_a4 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_bc_a4_aircraft_vertical_1750-2015_0.9x1.25_c20170608.nc',
'NO2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_NO2_aircraft_vertical_1750-2015_0.9x1.25_c20170608.nc',
'num_a1 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_so4_a1_anthro-ene_vertical_1750-2015_0.9x1.25_c20170616.nc',
'num_a1 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_a1_so4_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
'num_a2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_a2_so4_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
'num_a4 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_bc_a4_aircraft_vertical_1750-2015_0.9x1.25_c20170608.nc',
'SO2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_SO2_aircraft_vertical_1750-2015_0.9x1.25_c20170608.nc',
'SO2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_SO2_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
'SO2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/stratvolc/VolcanEESMv3.11_SO2_850-2016_Mscale_Zreduc_1deg_c180812.nc',
'so4_a1 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_so4_a1_anthro-ene_vertical_1750-2015_0.9x1.25_c20170616.nc',
'so4_a1 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_so4_a1_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
'so4_a2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_so4_a2_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc'
In WACCM6, stratospheric aerosol injections are handled via the external forcing. In the namelist, this is a list of emissions files and corresponding species in the ext_frc_specifier. For example, below is the default list for the BWHIST compset.
If you want to do stratospheric SO2 injections, you would create a similar emissions file describing the region where you want SO2 emitted. You can also add a scale factor in front of the path to the emissions file, such as "4*" to multiply the emission rates by a factor of 4.
ext_frc_specifier = 'bc_a4 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_bc_a4_aircraft_vertical_1750-2015_0.9x1.25_c20170608.nc',
'NO2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_NO2_aircraft_vertical_1750-2015_0.9x1.25_c20170608.nc',
'num_a1 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_so4_a1_anthro-ene_vertical_1750-2015_0.9x1.25_c20170616.nc',
'num_a1 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_a1_so4_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
'num_a2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_a2_so4_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
'num_a4 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_num_bc_a4_aircraft_vertical_1750-2015_0.9x1.25_c20170608.nc',
'SO2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_SO2_aircraft_vertical_1750-2015_0.9x1.25_c20170608.nc',
'SO2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_SO2_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
'SO2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/stratvolc/VolcanEESMv3.11_SO2_850-2016_Mscale_Zreduc_1deg_c180812.nc',
'so4_a1 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_so4_a1_anthro-ene_vertical_1750-2015_0.9x1.25_c20170616.nc',
'so4_a1 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_so4_a1_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc',
'so4_a2 -> /glade/p/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/emissions-cmip6_so4_a2_contvolcano_vertical_850-5000_0.9x1.25_c20170724.nc'
Since the version of the CESM model I am relying on is 1.2.2, I can only use WACCM5 to complete my experiments. So, how should I add this forcing data in WACCM5 and how do I get the forcing files I need?
As well as before I saw that you had answered under another post (transient volcano forcing in WACCM): CESM1 uses prescribed stratospheric aerosols. In CESM1(WACCM), these are prescribed in the sad_file.
So should I change the sad_file or the ext_frc_specifier ?
Thank you very much!!
Since the version of the CESM model I am relying on is 1.2.2, I can only use CAM5-WACCM(WACCM5) to complete my experiments. So, how should I add this forcing data in WACCM5 and how do I get the forcing files I need?
As well as before I saw that you had answered under another post (transient volcano forcing in WACCM): CESM1 uses prescribed stratospheric aerosols. In CESM1(WACCM), these are prescribed in the sad_file.
So should I change the sad_file or the ext_frc_specifier ?
Thank you very much!!
WACCM5 is generally not a defined model version, and I can't recall right now why we released this one WACCM5 compset. It has MAM aerosols, but it also has the sad_file, and does not have OCS. This indicates that it does not have interactive stratospheric aerosols, but rather uses the sad_file to prescribe them. So you should modify the sad_file, not the ext_frc_specifier.
WACCM4 also uses the sad_file for prescribed stratospheric aerosols. WACCM4 was the version used for CMIP3, so it is well defined and validated. Is there a reason why you chose WACCM5 over WACCM4 for your studies?
Is there a reason why you can't use CESM2(WACCM6) with interactive stratospheric aerosols? It is also supported at 1.9°x2.5° horizontal resolution.
WACCM4 also uses the sad_file for prescribed stratospheric aerosols. WACCM4 was the version used for CMIP3, so it is well defined and validated. Is there a reason why you chose WACCM5 over WACCM4 for your studies?
Is there a reason why you can't use CESM2(WACCM6) with interactive stratospheric aerosols? It is also supported at 1.9°x2.5° horizontal resolution.
Does this mean that in CESM 1.2.2 there are no interactive stratospheric aerosols in either WACCM5 or WACCM4? However, I have seen researchers in related studies mentioning that CESM1 (WACCM) is able to study stratospheric aerosols better due to the interactive atmospheric chemistry, you can see the attached research paper for details.
Besides, I have two more questions: firstly, is the volcano forcing nc file required to change the sad file in WACCM4 and WACCM5 available on the official website? Secondly, if I choose to use CESM2 (WACCM6), is it only the sad file that needs to be changed or should I change the other namelist?
I am very sorry that I can only put down the titles and screenshots of the literature due to the oversized attachments.
① Modeling the 1783–1784 Laki Eruption in Iceland:1. Aerosol Evolution and Global Stratospheric Circulation Impacts
② Global food insecurity and famine from reduced crop, marine fishery and livestock production due to climate disruption from nuclear war soot injection.
③ Radiative and Chemical Response to Interactive Stratospheric Sulfate Aerosols in Fully Coupled CESM1(WACCM)
④ Global volcanic aerosol properties derived from emissions, 1990-2014, using CESM1(WACCM)
① Modeling the 1783–1784 Laki Eruption in Iceland:1. Aerosol Evolution and Global Stratospheric Circulation Impacts
② Global food insecurity and famine from reduced crop, marine fishery and livestock production due to climate disruption from nuclear war soot injection.
③ Radiative and Chemical Response to Interactive Stratospheric Sulfate Aerosols in Fully Coupled CESM1(WACCM)
④ Global volcanic aerosol properties derived from emissions, 1990-2014, using CESM1(WACCM)
The second paper (Xia et al., 2022) does not include interactive stratospheric aerosols.
The other published studies above were started prior to the development of CESM2(WACCM6), and used development versions of the model that ultimately led to the creation of CESM2(WACCM6). Those versions with interactive stratospheric aerosols were not released, since CESM2(WACCM6) is the finished version.
The other published studies above were started prior to the development of CESM2(WACCM6), and used development versions of the model that ultimately led to the creation of CESM2(WACCM6). Those versions with interactive stratospheric aerosols were not released, since CESM2(WACCM6) is the finished version.
Correct. The only public release of CESM that includes interactive stratospheric aerosols is CESM2(WACCM6). The other published studies above were started prior to the development of CESM2(WACCM6), and used development versions of the model that ultimately led to the creation of CESM2(WACCM6). Those versions with interactive stratospheric aerosols were not released, since CESM2(WACCM6) is the finished version.
CESM2(WACCM6) does not use the sad_file. It uses SO2 emissions from eruptions specified in the ext_frc_specifier. It also includes other sulfur gas emissions from non-volcanic sources, including OCS, DMS, and SO2 pollution.
I seem to understand what you mean.Thank you very much!