Aura Microwave Limb Sounder Upper Stratospheric/Lower Mesospheric (USLM) Carbon Monoxide Observations in Arctic Winter 2009-2010: Analysis of An Anomalous Mixing Event
Abstract
The 2009--2010 Arctic winter was notable for a strong, prolonged stratospheric sudden warming (SSW) beginning in late January; this SSW disrupted the stratospheric circulation to a degree similar to that of the 2006 and 2009 SSWs, but had a smaller impact on the mesospheric circulation. Prior to the 2010 SSW, trace gas fields from Aura Microwave Limb Sounder (MLS) observations show the signature of an unusual event suggesting a large intrusion of air from outside the vortex mixed into the vortex region, with the signature of this event subsequently propagating downwards via diabatic descent. A SLIMCAT chemistry transport model simulation captures this anomalous mixing event. Carbon monoxide (CO) is an especially useful tracer of air motions in the upper stratosphere/lower mesosphere (USLM). We analyse MLS and SLIMCAT CO fields, supported by examination of other trace gas data, to provide an overview of transport during the 2009-2010 winter, focusing on detailed analysis of the unusual USLM mixing event.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMSA31B1731M
- Keywords:
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- 0340 ATMOSPHERIC COMPOSITION AND STRUCTURE / Middle atmosphere: composition and chemistry;
- 0341 ATMOSPHERIC COMPOSITION AND STRUCTURE / Middle atmosphere: constituent transport and chemistry;
- 3334 ATMOSPHERIC PROCESSES / Middle atmosphere dynamics;
- 3360 ATMOSPHERIC PROCESSES / Remote sensing