WIP - Chi-factor for CO2

[erwanp]

Description

This pull request is to address ...

Fixes #

[erwanp]

@pgokulak It might be possible to avoid rewriting existing code such as voigt_lineshape
For instance :

lineshape = voigt_lineshape(...) # keep the default
lineshape *= self.add_chi_factor(self.input.molecule)  

Where most of the new code is added in add_chi_factor:

def add_chi_factor(molecule, w_centered, wv):
     """molecule, wavenumber array, voigt width"""
    if molecule == 'CO2':
        pressure_mbar = self.input.pressure_mbar
        mole_fraction = self.input.mole_fraction  # note, might be a dictionary if mulitple molecules ? check later
        Tgas = self.input.Tgas
        Tref = self.input.Tref

        xi_factor = get_xiFactor(pressure_mbar*1e-3, mole_fraction, Tgas, Tref)

     # xi_factor correction for pseudo-Lorentzian of Westlye et al.(2022)
        gamma_v = wv/2 # Voigt half-width
        alpha_xi = xi_factor*np.sin(np.pi/xi_factor)/(2*np.pi*gamma_v) # see see Westlye et al. (2022); Eqn(6)
        lineshape_correction = alpha_xi / (1 + abs(w_centered/gamma_v)**xi_factor) # see see Westlye et al. (2022); Eqn(5)

        return lineshape_correction
    else:
        raise NotImplementedError

This would make it easier to maintain the codebase

[erwanp]

@pgokulak can we proceed towards merging these new additions ?

[pgokulak]

Erwan: Yes. CO2 lineshape correction (i.e., chi_correction) in the latest version is based on a pseudo-Lorentzian correction factor (i.e., xi_factor). It is validated for high-pressure conditions for 4.3 micron band. Regards, -Gokul-

…

On Tue, Mar 21, 2023 at 10:52 AM Erwan Pannier ***@***.***> wrote: @pgokulak <https://github.com/pgokulak> can we proceed towards merging these new additions ? — Reply to this email directly, view it on GitHub <#533 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ARUWFE6QRYKF5CHWJSLJLX3W5G6BJANCNFSM6AAAAAATLPUZ7E> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[erwanp]

we should add this only if the molecule is CO2.

I can take this one if you want @pgokulak