Potential Global Climate Effects of Asteroids Impacting Earth's Oceans
Abstract
Water waves generated by the impacts of asteroids into oceans have been recognized as a potentially catastrophic risk to people and infrastructure in coastal regions. Another consequence of ocean impact is the potentially global effects of an event that would otherwise be of only regional or local importance, should it occur on land. Only a fraction of the total impact energy is converted into water waves that have the ability to globally propagate in the oceans. The remaining energy is consumed by the "evaporation" of the asteroid, the ocean water being transformed into vapor and mist and the fractionization of ocean water and vapor into chlorine and bromine which alter the atmospheric chemistry, therefore impacting globally the Ozone layer and earth temperature. In this paper, we present our scheme of creating the source -- including nonlinear transient cratering and nearfield waves, generating the vapor cloud and the chemical speciation source load of chlorine and bromine to assess the global circulation of those plumes and their effects on the climate. We present our coupling scheme of the hydrodynamic source using Geodyn with the global atmospheric circulation code GEOSCCM and illustrate the scheme on the PDC 2017 and PDC 2019 asteroid impact scenarios. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMNH51C0793E
- Keywords:
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- 4301 Atmospheric;
- NATURAL HAZARDS;
- 4314 Mathematical and computer modeling;
- NATURAL HAZARDS;
- 6008 Composition;
- PLANETARY SCIENCES: COMETS AND SMALL BODIES;
- 6022 Impact phenomena;
- PLANETARY SCIENCES: COMETS AND SMALL BODIES