Sea ice and ocean water vapor isotopes

A warming climate results in sea ice loss and impacts to the Arctic water cycle. The water isotope parameter deuterium excess, a moisture source proxy, can serve as a tracer to help understand hydrological changes due to sea ice loss. However, unlocking the sea ice change signal of isotopes from ice cores requires understanding how sea ice changes impact deuterium excess, which is unknown. Here we present the first isotope data linking a gradient of sea ice extents to oceanic water vapor deuterium excess values. Initial loss of sea ice extent leads to lower deuterium excess moisture sources, and then values progressively increase with further ice loss. Our new process-based interpretation suggests that past rapid (1–3 years) Greenland ice core changes in deuterium excess during warming might not be the result of abrupt atmospheric circulation shifts, but rather gradual loss of sea ice extent at northern latitude moisture sources. These data are in the following publication: Klein, E. S., and J. M. Welker (2016), Influence of sea ice on ocean water vapor isotopes and Greenland ice core records, Geophys. Res. Lett., 43, doi:10.1002/2016GL071748.