Atmospheric absorption, spectra, units and code: companion page to the global warming explanation post - Bert Hubert's writings
a day ago
- This page is a companion to an upcoming global warming blog post, serving as a teaser and seeking expert review from climate scientists.
- Different fields use various units for absorption (e.g., cm⁻¹, m⁻¹, m²/kg, m²/mol), leading to confusion; the page explains how to convert between them.
- The mass attenuation coefficient (m²/kg) represents the effective cross-sectional area per kilogram of material, and multiplying by density gives the linear attenuation coefficient (m⁻¹).
- Databases like HITRAN provide line intensities for gases, while the MT_CKD project supplies continuum spectra; both require careful unit conversion and interpolation.
- The HITRAN API (hapi) and Python code are used to retrieve and compute absorption coefficients, with the Hartmann-Tran algorithm handling line broadening.
- The page provides code snippets for fetching HITRAN data, calculating blackbody radiation, and obtaining absorption per molecule, including handling the water vapor continuum.
- A checklist helps identify serious climate research: requiring open source code, considering water continuum, and checking time series for biases like El Niño or Pinatubo.
- The author notes that water vapor has a larger greenhouse effect than CO₂, but questions the origin of that water vapor in climate claims.