Isotopic Measurements of Atmospheric Molecular Hydrogen (H2)

University Of Washington, Seattle WA

Investigators

Abstract

This project is investigating the atmospheric hydrogen (H2) budget using isotopic measurements. H2 is the second most abundant reactive gas in the troposphere and is directly tied to the cycling of carbon monoxide (CO), methane (CH4), and non-methane hydrocarbons via the photochemical formation and destruction of formaldehyde (HCHO). Currently, the global H2 budget is balanced only to within about 50%. Measurements are being made of the ratio of deuterium to hydrogen (D/H) in marine locations, in areas during biomass burning, and in H2 produced by the photolysis of HCHO, and during soil uptake of H2. The degree of enrichment of deuterium in these samples will indicate the relative importance of the soil and the photochemical sinks for H2. This work is helping to resolve the current discrepancies in the global budget of H2 and contribute to the overall understanding of the importance of increasing concentrations of CO, CH4, and H2 in the troposphere. Also, if H2 becomes an important energy source in the future, it will become even more important to understand its global budget.