Units error

[Nicholaswogan]

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]

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

[jrmascio]

@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]

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.