Robust winter warming over the Northern Hemisphere continents under stratospheric sulfate geoengineering
Abstract
The Geoengineering Large Ensemble (GLENS) simulations of the 21st century provide a unique opportunity to understand the potential side effects of stratospheric sulfate geoengineering aimed at controlling global mean surface temperature and large-scale temperature gradients under rising CO2 emissions. Here, we find that the sulfate geoengineering in these simulations causes wintertime surface warming over Northern Europe and the North Atlantic, and sea level pressure changes that project onto the positive phase of the North Atlantic Oscillation (NAO), by the end of the century (2075-2095 minus 2010-2030). A similar response has been suggested in the literature in response to the eruption of large tropical volcanoes such as Mt. Pinatubo, but there, the relative roles of forcing versus internal climate variability remains in question. In contrast, the GLENS simulations show a large signal-to-noise ratio under the much larger stratospheric aerosol loadings, with the annual injection rate reaching 5 times the Pinatubo sulfur burden by the end of the century. We examine the extent to which stratospheric changes - tropical lower stratospheric warming, an increased equator-to-pole temperature gradient and a strengthened Northern Hemisphere polar vortex - drives the tropospheric and surface signals.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGC31B..03B
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3319 General circulation;
- ATMOSPHERIC PROCESSES;
- 6309 Decision making under uncertainty;
- POLICY SCIENCES & PUBLIC ISSUES