A Simple Approach for Atmospheric Hydrogen Modelling Based on the Seasonal Variability

Anthropogenic hydrogen emissions to the atmosphere have the potential to increase if there is a proliferation of hydrogen as a fuel in the future (Warwick et al., 2023).  It is well understood that atmospheric hydrogen has a positive indirect global warming potential (Ocko and Hamburg, 2022; Sand et al., 2023).  However, substantial uncertainty remains in evaluating this global warming potential, and how this value depends on the distribution of emissions.  Principally, the most appropriate surface deposition scheme to use in models remains unclear (Paulot et al., 2021). Motivated by the observation that the seasonal variability of station hydrogen measurements (from Petron et al., 2023) can be well described as a function of latitude, we present an idealised latitude-height model for testing prototype deposition schemes.  We show how much of the key features of the seasonal variability can be captured with an illustrative benchmark deposition scheme, and finally how this model can be used to iteratively develop existing deposition schemes (e.g. Bertagni et al., 2021).