A climatological assessment of intense extratropical cyclones from the potential vorticity perspective

dc.contributor.authorSeiler, Christian
dc.date.accessioned2025-04-10T20:27:23Z
dc.date.available2025-04-10T20:27:23Z
dc.date.issued2019
dc.description.abstractExtratropical cyclones (ETCs) are known to intensify due to three vertically interacting positive potential vorticity perturbations that are associated with potential temperature anomalies close to the surface (θB), condensational heating in the lower-level atmosphere (qsat), and stratospheric intrusion in the upper-level atmosphere (qtr). This study presents the first climatological assessment of how much each of these three mechanisms contributes to the intensity of extreme ETCs. Using relative vorticity at 850 hPa as a measure of ETC intensity, results show that in about half of all cases the largest contributions during maximum ETC intensity are associated with qsat (53% of all ETCs), followed by qtr (36%) and θB (11%). The relative frequency of storms that are dominated by qsat is higher 1) during warmer months (61% of all ETCs during warmer months) compared to colder months (50%) and 2) in the Pacific (56% of all ETCs in the Pacific) compared to the Atlantic (46%). The relative frequency of ETCs that are dominated by θB is larger 1) during colder months (13%) compared to warmer months (3%), 2) in the Atlantic (15%) compared to the Pacific (8%), and 3) in western (11%–20%) compared to eastern ocean basins (4%–9%). These findings are based on piecewise potential vorticity inversion conducted for intense ETCs that occurred from 1980 to 2016 in the Northern Hemisphere (3273 events; top 7%). The results may serve as a baseline for evaluating ETC biases and uncertainties in global climate models.
dc.description.reviewstatusReviewed
dc.description.scholarlevelFaculty
dc.identifier.citationSeiler, C. (2019). A climatological assessment of intense extratropical cyclones from the potential vorticity perspective. Journal of Climate, 32(8), 2369–2380. https://doi.org/10.1175/JCLI-D-18-0461.1
dc.identifier.urihttps://doi.org/10.1175/JCLI-D-18-0461.1
dc.identifier.urihttps://hdl.handle.net/1828/21756
dc.language.isoen
dc.publisherJournal of Climate
dc.subjectUN SDG 13: Climate Action
dc.subject#journal article
dc.subjectPacific Climate Impacts Consortium (PCIC)
dc.titleA climatological assessment of intense extratropical cyclones from the potential vorticity perspective
dc.typeArticle

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