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AER-RC / MT_CKD

AER continuum model for water vapor and other gases.
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Units error #1

Open Nicholaswogan opened 2 years ago

Nicholaswogan commented 2 years ago

What are the units in the outputted file WATER.COEFF? This line says that the 4th and 5th column has units of 1/(molec/cm**2). But these are not the units? I think the units of the 4th and 5th column are

1/(molecules/cm^2) * (1/amagat)

pernak18 commented 2 years ago

@jrmascio can you look at this when you have the time? please and thanks

jrmascio commented 2 years ago

@Nicholaswogan the units are cm^2/molecule/reference density, where the default reference density corresponds to a pressure of 1013 mbar and a temperature of 296K (or whichever pressure and temperature you use as input to run MT_CKD by itself). The units will be changed in the WATER.COEFF file in the next release.

Nicholaswogan commented 2 years ago

I'm confused by this reference pressure. Can you explicitly say the definition of the optical depth, given the output coefficients in WATER.COEFF? Consider "self" absorption. In this case

tau = ?

For example, It would be useful if the program output [cm^2/molecule]*[cm^3/molecule]. In the case of the "self" absorption, then multiplying H2O density (molecules/cm^3) two times, and by the thickness of a layer in cm yields the optical depth

tau = [cm^2/molecule]*[cm^3/molecule] * [molecules/cm^3] * [molecules/cm^3] * [cm]

I think most people would understand the above formulation.