Science Daily October 25, 2022
A team of researchers in the US (U Mass. Amherst, University of Alaska) studied the mechanisms of precipitation deuterium excess (d-excess) seasonality in low-latitudes and mid-latitudes through a new analysis of precipitation isotope databases along with climate reanalysis products and moisture tracking models. The ultimate d-excess signals are produced after complex modulations by several reinforcing or competing processes. They developed a simple seasonal water storage model to show that contributions of previously evaporated residual water storage and higher transpiration fractions may lead to relatively low d-excess in evapotranspiration fluxes during periods of enhanced continental moisture recycling. This study underscores the ubiquitous nonconservative behavior in d-excess throughout the water cycle, as opposed to using d-excess as a simple tracer for remote conditions at oceanic moisture sources. According to the researchers thier study refines our understanding of the chemical traces that act as the rain’s fingerprint. …read more. Open Access TECHNICAL ARTICLE
The map showing the locations of analyzed GNIP/USNIP stations (gray dots)… Credit: Global Biogeochemical Cycles, 2022; 36 (10)Â