The QBO and ENSO Influence on Upper Tropospheric and Lower Stratospheric Ozone From a Subtropical Jet Perspective
Abstract
The upper troposphere/lower stratosphere (UTLS) composition around the subtropical jets (STJ) is highly variable, at least in part due to significant stratosphere-troposphere exchange dynamically associated with the jets. There are large horizontal and vertical gradients across the jets, whose location is also highly variable. Using a jet-based coordinate system can reduce much of the apparent composition variability associated with the jet movement, sharpen the gradients, and highlight distinct air masses. In this study, we use GEOS-5 data assimilation of OMI and MLS ozone observations to investigate the influence of the Quasi-Biennial Oscillation (QBO) and El Niño Southern Oscillation (ENSO) on the variability of ozone in the subtropical and midlatitude UTLS. The ozone analyses are placed in a STJ coordinate system based upon the horizontal and vertical distance from the jet cores in the Northern and Southern Hemispheres. Multiple linear regression is used to give the spatial distribution of the variance and sensitivity of UTLS ozone that is uniquely attributable to the QBO and ENSO time series. In the Northern Hemisphere, we will show the greatest impact from QBO and ENSO is in the stratosphere above and poleward of the STJ when considering the entire hemisphere. The hemispheric tropospheric response is generally not statistically significant. However, the response varies considerably by longitude, particularly in the troposphere. The tropospheric response is significant and greatest in the northern Pacific where the influence is through increased stratosphere to troposphere transport of ozone. The stratospheric origin of this transport differs between the ENSO and QBO influence. The ENSO influence originates from the lowermost stratosphere while the QBO influence originates from slightly higher altitudes. Finally, the response in the Northern and Southern Hemispheres will be compared and contrasted.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A11E0071O
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSESDE: 3362 Stratosphere/troposphere interactions;
- ATMOSPHERIC PROCESSESDE: 1620 Climate dynamics;
- GLOBAL CHANGE