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AtChem / AtChem2

Atmospheric chemistry box-model for the MCM
MIT License
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Emission of species #484

Closed morshedahmed17 closed 1 year ago

morshedahmed17 commented 1 year ago

Hello, I was trying to add the emission (Er) of species P1 using the following command in the mechanism file.
% Er : = P1 ; However, no change is observed in the species concentration. Any idea?

morshedahmed17 commented 1 year ago

Hello, The emission rate is working on my end now. I had some issues with my university cluster and I was not getting output update which is resolved now. You can close this issue.

morshedahmed17 commented 1 year ago

Hello, The unit of emission rate "Er" is reciprocal seconds (s-1) according to the paper "AtChem (version 1), an open-source box model for the Master Chemical Mechanism". However, the emission rate unit is in a format of mass/time. Do you have any idea why it is only s-1 in the paper?

rs028 commented 1 year ago

@morshedahmed17 the emission rate coefficient is in 1/time, the emission rate is in mass/time. Hope it makes sense.

morshedahmed17 commented 1 year ago

@rs028 In the paper it says "emission rate" not "emission rate coefficient". And what is the physical meaning of the term emission rate coefficient?

rs028 commented 1 year ago

@morshedahmed17 in AtChem, processes like emissions and deposition are represented as "chemical reactions". It is simply a shortcut to write a differential equation that the program already knows how to pass to the solver. See Section 3.1.1 in the Manual for details.

morshedahmed17 commented 1 year ago

@rs028 is it possible to use constrained emission data?

rs028 commented 1 year ago

@morshedahmed17 do you mean constrain the emission rate or the concentration?

morshedahmed17 commented 1 year ago

@rs028 yes, constrain emission rate.

rs028 commented 1 year ago

The model is not currently set up to do that. In theory it is possible. For example, the photolysis rates can be constrained. You would need to modify the code to define a new variable and to allow this variable to be constrained. I did something similar when I added the Aerosol Surface Area to the model (see #473 and #432 for information).