The input data about the volcanic sensitive experiment

[Liu W]

Hi, everyone.
I plan to conduct some sensitive experiments related to volcanic eruptions with CESM1.2(CAM5) and CESM2.2(CAM6). I have known that sulfur dioxides on behalf of a volcanic eruption can be input to CESM-WACCM, while the computing resources of WACCM are too huge. I wonder how the properties of volcanic aerosol (e.g., single scattering albedo) directly describe the volcanic eruption in CAM5 and CAM6. In other word, I have the descriptive file about volcanic aerosols (obtained with Easy Volcanic Aerosol model), so which corresponding files in the CAM5 and CAM6 should I modify respectively?
Any reply and discussion are appreciative.

 

[rrbuchholz]

Hi Liu,
Could you clarify whether you want to adjust the volcanic aerosol emissions amount, or the volcanic aerosol properties?
Best,
Rebecca

 

[Liu W]

Hi Liu,
Could you clarify whether you want to adjust the volcanic aerosol emissions amount, or the volcanic aerosol properties?
Best,
Rebecca

I am sorry for the late reply. I think that I need to adjust the MMRVOLC (layer volcanic aerosol mass mixing ratio). It seems easy to adjust the volcanic aerosol in CAM5 by changing the namelist file(prescribed_volcaero_nl). However, CAM6 prescribes the aerosol with 3 modes and disables to set the stratospheric aerosol and volcanic aerosol at the same time.

 

[mmills]

We considered running CAM6 with forcings from Easy Volcanic Aerosol, but it was not straightforward. As you note there are two methods for prescribing volcanic aerosols. The prescribed_strataero_file is the 3-mode WACCM6 output that is used in CAM6, while the prescribed_volcaero_file is the MMRVOLC used in CAM5. These are described in this paper:

Neely, R. R., Vitt, F., & Lamarque, J.-F. (2016). A consistent prescription of stratospheric aerosol for both radiation and chemistry in the Community Earth System Model (CESM1). Geoscientific Model Development, 9(7), 2459–2470. GMD - A consistent prescription of stratospheric aerosol for both radiation and chemistry in the Community Earth System Model (CESM1)

As you mention, it is not possible to run with both of these methods at the same time. Have you gotten CAM5 to run with the Easy Volcanic Aerosol forcing?

If so, perhaps you could run CAM6 with a prescribed_volcaero_file if you were able to turn off the prescribed_strataero_file. I have not tried this, so I don't know if it is possible.

 

[GaoYa]

I am sorry for the late reply. I think that I need to adjust the MMRVOLC (layer volcanic aerosol mass mixing ratio). It seems easy to adjust the volcanic aerosol in CAM5 by changing the namelist file(prescribed_volcaero_nl). However, CAM6 prescribes the aerosol with 3 modes and disables to set the stratospheric aerosol and volcanic aerosol at the same time.

Hello, I meet the same problem, too. Have you solved it?