Changes in Global Moisture Transport from Water Isotope Ratios
Abstract
Recent work shows that the zonal-mean structure of isotopes ratios in water vapor and precipitation depends essentially on two factors: the efficacy with which precipitation dries the atmosphere and the efficiency of moisture transport. These dependencies can be expressed in terms of a local drying ratio, which describes how much moisture gained through evaporation and transport is lost via precipitation, and a mean source distance, or average distance moisture is transported from afar. Estimating past and future (expected) changes in drying ratio from observations and simulations, this presentation works to attribute isotopic variations to changes in moisture transport. In this manner, the effects of local and remote water cycle changes are isotopically mapped to each latitudinal zone. A Bayesian statistical analysis is used to determine how confidently variations in mean source distance can be extracted from isotopic records when constraints on the local drying ratio are weak. Accounting for such uncertainties and the limitations of today's observational capacities, the likelihood of detecting climate-driven changes in global moisture transport with isotopic evidence is discussed.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMPP13B..03R
- Keywords:
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- 3344 Paleoclimatology;
- ATMOSPHERIC PROCESSESDE: 1041 Stable isotope geochemistry;
- GEOCHEMISTRYDE: 1655 Water cycles;
- GLOBAL CHANGEDE: 1833 Hydroclimatology;
- HYDROLOGY