Now at Departments of Mathematics and Civil, Chemical and Environmental Engineering, University of Surrey, Guildford, UK.
Objective detection of sting jets in low-resolution datasets
Article first published online: 4 OCT 2011
Copyright © 2011 Royal Meteorological Society and British Crown Copyright, the Met Office
Volume 20, Issue 1, pages 41–55, March 2013
How to Cite
Martínez-Alvarado, O., Gray, S. L., Clark, P. A. and Baker, L. H. (2013), Objective detection of sting jets in low-resolution datasets. Met. Apps, 20: 41–55. doi: 10.1002/met.297
- Issue published online: 4 MAR 2013
- Article first published online: 4 OCT 2011
- Manuscript Accepted: 15 AUG 2011
- Manuscript Revised: 5 AUG 2011
- Manuscript Received: 10 MAR 2011
- conditional symmetric instability;
- Shapiro–Keyser cyclone;
Sting jets are transient coherent mesoscale strong wind features that can cause damaging surface wind gusts in extratropical cyclones. Currently, we have only limited knowledge of their climatological characteristics. Numerical weather prediction models require enough resolution to represent slantwise motions with horizontal scales of tens of kilometres and vertical scales of just a few hundred metres to represent sting jets. Hence, the climatological characteristics of sting jets and the associated extratropical cyclones cannot be determined by searching for sting jets in low-resolution datasets such as reanalyses.
A diagnostic is presented and evaluated for the detection in low-resolution datasets of atmospheric regions from which sting jets may originate. Previous studies have shown that conditional symmetric instability (CSI) is present in all storms studied with sting jets, while other rapidly developing storms of a similar character but no CSI do not develop sting jets. Therefore, it is assumed that the release of CSI is needed for sting jets to develop. While this instability will not be released in a physically realistic way in low-resolution models (and hence sting jets are unlikely to occur), it is hypothesized that the signature of this instability (combined with other criteria that restrict analysis to moist mid-tropospheric regions in the neighbourhood of a secondary cold front) can be used to identify cyclones in which sting jets occurred in reality. The diagnostic is evaluated, and appropriate parameter thresholds defined, by applying it to three case studies simulated using two resolutions (with CSI-release resolved in only the higher-resolution simulation). Copyright © 2011 Royal Meteorological Society and British Crown Copyright, the Met Office