Horizontal potential vorticity dipoles on the convective storm scale

Chagnon, J. M. and Gray, S. L. ORCID: https://orcid.org/0000-0001-8658-362X (2009) Horizontal potential vorticity dipoles on the convective storm scale. Quarterly Journal of the Royal Meteorological Society, 135 (643). pp. 1392-1408. ISSN 1477-870X doi: 10.1002/qj.468

Abstract/Summary

The structure and dynamics of potential vorticity (PV) anomalies generated by convective storms is investigated both theoretically and in a numerical model case study. Linear theory suggests that if the storm-induced heating is on a sufficiently small scale (relative to the Rossby radius of deformation), and the environment contains moderate vertical wind shear (of order 1 m s(-1) km(-1)), then the dominant mode of a diabatically generated PV anomaly is a horizontally oriented dipole. The horizontal dipoles are typically of O(10 PVU), compared with the O(1 PVU) vertical dipoles that have been studied extensively throughout the literature. Furthermore, the horizontal PV dipoles are realized almost entirely as relative vorticity anomalies (on a time-scale of the order of tens of minutes after the heating has been turned on). The analysis of horizontal PV dipoles offers a new perspective on the vorticity dynamics of individual convective cells, implying that moist processes play a role in the maintenance of vertical vorticity in the convective storm environment.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/7637
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Uncontrolled Keywords	potential vorticity;convection;diabatic processes;mesoscale mesoscale convective vortices
Publisher	Royal Meteorological Society
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