[Eoas-seminar] Meteorology MS Defense for Gwen Dmitruk, Friday, November 20, 2020, 9:000 AM, on Zoom https://fsu.zoom.us/j/96603347130?pwd=eU5oRGZ6QXorUlkzNWFjbm9KZEo2UT09

[eoas-seminar at lists.fsu.edu]

Meteorology Seminar

Gwendolyn Dmitruk

M.S. Meteorology Candidate



Title:  A globe-circling synoptic-Scale winter disturbance In Northern hemisphere midlatitudes



Major Professor: Dr. Jon Ahlquist

Date: Friday, 20 November 2020                                 Time: 09:00 AM



Location: Zoom Meeting (URL: https://fsu.zoom.us/j/96603347130?pwd=eU5oRGZ6QXorUlkzNWFjbm9KZEo2UT09<https://urldefense.com/v3/__https:/fsu.zoom.us/j/96603347130?pwd=eU5oRGZ6QXorUlkzNWFjbm9KZEo2UT09__;!!Epnw_ITfSMW4!4hQIKmwGqAf7oSUs3hXuMv3VqVYFK2XfBu4ka2w_HIfmL2rWdytDHHxKlgqvXX7pu2k$>)



ABSTRACT

This study examines the possibility that winter storms developing off the east coast of Asia may trigger storms developing off the east coast of North American and vice versa. We focus on one point off the northeastern coast of North America and another off the northeastern coast of Asia where relative vorticity and height fluctuations are large. The starting point was identifying the 100 most prominent vorticity maxima at 500 hPa at each of these points during sixty 150-day cold seasons beginning on 1 November of each year from 1958 to 2017.  Global composites were computed across multiple pressure levels from these events, spanning 25 days before to 25 days after the time of a relative vorticity maximum. This allowed for observation of the disturbance from 1000 hPa to 1 hPa. At the time of the vorticity maxima, the composite shows an untilted feature about 5° of latitude (560 km) in diameter extending from 1000 hPa to 100 hPa, decaying rapidly above that. Composites confirmed the existence of the wave pattern, which travels eastward across the Atlantic with maintained strength after reaching a peak off the coast of Nova Scotia (at t = 0). It rapidly loses this strength and gains a notable southward component to its trajectory after reaching the European coastline but still visibly treks eastward across Asia in its weakened state. Upon reaching the Pacific (at 9-10 days), it surges in relative vorticity strength again. This strength is likewise maintained across the North Pacific, until it similarly and significantly weakens in strength and attains a southeastern trajectory upon contact with the North America, only to reemerge in a week's time to repeat the pattern once again at 19-20 days, increasing and maintaining strength along the North Atlantic. Similar results are repeated using height composites, with wave signal location, speed, and strength mirroring that of the relative vorticity composites. Case studies of individual events allow for the indexing and chronicling of the events life cycle.



Shel McGuire
Florida State University
Academic Program Specialist
Department of Earth, Ocean, & Atmospheric Science
1011 Academic Way, 2019 EOA Building
Tallahassee, FL 32306
850-644-8582
To make an appointment please login to my.fsu.edu and choose the Campus Connect (CC) icon

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