Is the aerosol in CAM affected by land?

[Song]

Hi,

I am new in CAM. I would like to ask whether the land use change can affect aerosol simulated by CAM. I am using CESM2.1.5 (with CAM6) and FHIST compset. I am running a simulation with land use changes. What I have known is that there is no aerosol emissions from CLM.

According to the "Description of CAM5", I learned that the anthropogenic aerosol emissions are taken from the IPCC AR5 emission data set. Since there is modal aerosol model serving in CAM5, I think the aerosol in different years should not be purely prescribed. However, I am not sure whether CAM takes into account any influence from land, either directly or indirectly.

Please feel free to correct me if I understand anything incorrectly. I would appreciate it if anyone could share some knowledge about this.

Best,
Song

 

[rrbuchholz]

Dear Song,

Two aerosol species that can be influenced by land are:
1. Dust - this is interactively calculated in CLM: Dust emissions - CAM-Chem - wiki.ucar.edu
2. Secondary organic aerosols - these are interactivel calculated using the MEGANv2.1 algorithm within CLM. Biogenic Emission Options (MEGAN) - CAM-Chem - wiki.ucar.edu

Hope that helps!
Best,
Rebecca

 

[Song]

Dear Song,

Two aerosol species that can be influenced by land are:
1. Dust - this is interactively calculated in CLM: Dust emissions - CAM-Chem - wiki.ucar.edu
2. Secondary organic aerosols - these are interactivel calculated using the MEGANv2.1 algorithm within CLM. Biogenic Emission Options (MEGAN) - CAM-Chem - wiki.ucar.edu

Hope that helps!
Best,
Rebecca

Thank you so much, Rebecca! This information is very helpful!

 

[Danny Leung]

Hi Song-
Dry depositions of aerosols are also affected by the land. Turbulent deposition of aerosols in CAM is calculated by employing friction velocity and aerodynamic resistance from CLM. Aerosols are not prescribed in CAM6 in an FHIST compset...
Hope this helps,
Danny

 

[Song]

Hi Song-
Dry depositions of aerosols are also affected by the land. Turbulent deposition of aerosols in CAM is calculated by employing friction velocity and aerodynamic resistance from CLM. Aerosols are not prescribed in CAM6 in an FHIST compset...
Hope this helps,
Danny

Hi Danny,

Thank you for your reply! Your and Rebecca's answers let me know that not only the production of some aerosol species is affected by land, but also the lifetime of aerosol is affected by land. With regard to "Aerosols are not prescribed in CAM6 in an FHIST compset", do you mean that the amount of aerosols is calculated entirely by CAM and not dependent on the IPCC emission data set?

Best,
Song

 

[Danny Leung]

Hi Song-
What I meant by "Aerosols are not prescribed in CAM6 in an FHIST compset" was that: Emissions are prescribed (e.g., most anthropogenic emissions are from the prescribed emission datasets/inventories) or modeled (like dust and seasalt emissions), while the amount or concentrations of aerosols in the atmosphere are definitely modeled (dependent on the modeled transport, deposition, and chemistry etc).
Some aerosol quantities (like aerosol depositions) were used to be prescribed in older CAM versions, but not anymore in your CAM6 FHIST case.
Danny

 

[Song]

Hi Song-
What I meant by "Aerosols are not prescribed in CAM6 in an FHIST compset" was that: Emissions are prescribed (e.g., most anthropogenic emissions are from the prescribed emission datasets/inventories) or modeled (like dust and seasalt emissions), while the amount or concentrations of aerosols in the atmosphere are definitely modeled (dependent on the modeled transport, deposition, and chemistry etc).
Some aerosol quantities (like aerosol depositions) were used to be prescribed in older CAM versions, but not anymore in your CAM6 FHIST case.
Danny

Thank you for the further explanation, Danny! I think this is very clear and helpful for me and everyone who is not familiar with CAM aerosols.