A Lagrangian Perspective on Polar Hydroclimate Perturbations in a Warmer World
Abstract
We use numerical water tracers implemented in a global climate model to study how polar hydroclimate responds to CO2-induced warming. While remote moisture sources are more important to polar precipitation year-round in the mean state, an increase in locally-sourced moisture dominates the hydrologic cycle perturbation response. In general, the polar hydroclimate response to CO2-induced warming is strongly seasonal: over both the Arctic and Antarctic, locally-sourced moisture constitutes a larger fraction of the precipitation in winter while remote sources become even more dominant in summer. The increased importance of local sources in winter is coincident with sea ice retreat, which greatly increases local sources of evaporation in the fall and winter months. In summer, however, an increase in remote moisture sources is consistent with an increase in moisture residence times and the moisture transport length scale, which we find to be a part of the robust hydrologic cycle response to CO2-induced warming globally. Given that locally-sourced moisture dominates the hydrologic cycle perturbation response in both the Arctic and Antarctic, we conclude that the polar hydroclimate response is distinct from that of the rest of the globe; as such, great care should be taken in interpretation of polar isotopic proxy records from climate states that differ significantly from that of the present.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMPP11C2036S
- Keywords:
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- 1616 Climate variability;
- GLOBAL CHANGEDE: 1833 Hydroclimatology;
- HYDROLOGYDE: 4928 Global climate models;
- PALEOCEANOGRAPHYDE: 4999 General or miscellaneous;
- PALEOCEANOGRAPHY