How is O3 dry deposition velocity calculated?

[Hemraj]

Hi,
I can see O3 deposition flux (DF_O3) as one of the model output variables, but couldn't track O3 dry deposition velocity (people use it to explain O3 variability). I am wondering if I overlooked this variable, how is it called, or do I need to set this variable manually to get it as output (how)?

Can I calculate deposition velocity from DF_O3, if yes, how?

Many thanks!

 

[rrbuchholz]

Hi Hemraj,

You can save deposition velocity with the variable DV_<species>
https://wiki.ucar.edu/display/camchem/Using+CAM-chem+Output

Or, can it be calculated by dividing the deposition flux (mass/area/time) by the air concentration (mass/volume): DV ≡ DF / C. So, for example:
DV_[ozone] ≡ DF_[ozone] / C_[ozone]

There is also more information on dry deposition in the scientific user guide:
6. Extensions to CAM — camdoc documentation

Hope that helps!
Rebecca

 

[Hemraj]

Dear Rebecca,
This is great. Thank you so much. Just want to make sure my calculation is approach are correct.

O3_dep_vel = DF_O3*R*TS / (O3_SRF*O3_MW*PS_all) # m/s

where,
DF_O3 # kg/m2/s
R = 8.314 # Pa m3/(mol K), gas constant
TS #K
O3_SRF #mol/mol
O3_MW = 48/1000 # kg/mol
PS # Pa

Thank you!
Hemraj