Hyperspectral Characterization of Absorption and Scattering Coefficients of Atmospheric gazes: A Molecular Spectroscopy Approach for Radiative Transfer Applications in Tropical Atmospheres

TropiSpec-LBL is a line-by-line (LBL) radiative transfer pipeline built to quantify solar radiative transfer in the tropical atmosphere above Yaoundé, Cameroon (3.87°N, 11.52°E, ~750 m a.s.l.). Every input parameter is anchored in real observational or reanalysis data rather than generic literature profiles. The pipeline computes hyperspectral line-by-line absorption coefficients for five atmospheric gases from HITRAN2020, explicitly recalculates the Voigt profile at each real atmospheric level and quantifies the bias of the common interpolated approximation, computes Rayleigh and Mie scattering for three locally-calibrated aerosol types (using real MODIS MOD08_M3 and ERA5 boundary-layer data), cross-validates against ERA5, MODIS and Akana & Njomo (2009), and compares the results against three classical broadband solar radiation models. This code produced all quantitative results reported in Djampou Tchouankap, Akana Nguimdo & Njomo (2026), Journal of Geophysical Research: Atmospheres (submitted). Written in Python; depends on HAPI, PyMieScatt, xarray/cdsapi and pyhdf. See the accompanying README for requirements, execution order and external data sources (HITRAN2020, ERA5, MODIS MOD08_M3), which are not redistributed in this archive.