A Unified Interpretation of Variability in Precipitation Isotope Ratios

• DOI: 10.1175/jcli-d-24-0427.1
• Publication Date: 2025-02-24T13:52:11Z
• Authors: Nicholas Siler; Richard P. Fiorella; Tyler Kukla
• Keywords: Paleoclimatology

Abstract Several mechanisms have been proposed to explain why the isotope ratios of precipitation vary in space and time they correlate with other climate variables like temperature precipitation. Here we argue that this behavior is best understood through lens radiative transfer, which treats depletion atmospheric vapor transport by as analogous attenuation light absorption or scattering. Building on earlier work Siler et al. (2021), introduce a simple model uses equations transfer approximate two-dimensional pattern oxygen composition ( δ p ) from monthly-mean hydrologic variables. The accurately simulates spatial seasonal variability within state-of-the-art model, permits decomposition into contributions gradients evaporation length scale transport. Outside tropics, mostly controlled evaporation, whose dependence explains positive correlation between i.e ., effect). At low latitudes, scale, inverse relationship negative amount This suggests effects are both explained upstream rainout, but reflect distinct governing rainout at different latitudes.