Resolving a long-standing model-observation discrepancy on ozone solar-cycle response
Abstract
To have the capability for long-term prediction of stratospheric ozone (O3), chemistry-climate models have often been tested against observations on decadal time scales. A model-observation discrepancy in the tropical O3 response to the 11-year solar cycle, first noted in 1993, persists for more than 20 years: While standard photochemical models predict a single-peak response in the stratosphere, satellite observations show an unexpected double-peak structure. Various studies have explored uncertainties in photochemistry and dynamics but there has not been compelling evidence of model biases. Here we suggest that decadal satellite orbital drifts relative to the diurnal cycle could be the primary cause of the discrepancy. We show that the double-peak structure can be reproduced by adding the AM/PM diurnal difference to the single-peak response predicted by the standard photochemistry. This work illustrates the importance of a synergistic and iterative process involving observations and theory in search of robust climate signals.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMSA51B2419L
- Keywords:
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- 0340 Middle atmosphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 1650 Solar variability;
- GLOBAL CHANGEDE: 7514 Energetic particles;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMYDE: 7538 Solar irradiance;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY