University of Illinois Urbana-Champaign

A genesis potential index for polar lows

Boyd, Kevin Patrick

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https://hdl.handle.net/2142/115479

Description

Title
A genesis potential index for polar lows
Author(s)
Boyd, Kevin Patrick
Issue Date
2022-04-26
Director of Research (if dissertation) or Advisor (if thesis)
Wang, Zhuo
Committee Member(s)
  • Rauber, Robert
  • Sriver, Ryan
  • Walsh, John
Department of Study
Atmospheric Sciences
Discipline
Atmospheric Sciences
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Keyword(s)
  • Polar Lows
  • Statistical Modelling
  • Arctic
  • Climate
Abstract
Polar lows (PL) are intense maritime mesocyclones that develop during marine cold-air outbreaks events over the high-latitudes. The impacts posed by these systems to humans and the broader environment demand a robust understanding of the environmental factors that promote PL formation, and in turn, skillful prediction of PL activity. We hypothesize that the variability of PL activity is associated with some key, large-scale climate variables skewed towards “extreme” values, which can provide predictable information on PL activity beyond the synoptic time scale. A PL genesis potential index (PGI) is developed that relates the climatological spatial distribution of PL genesis frequency and key climate variables in a Poisson regression framework. The optimal set of predictors consists of a static stability parameter and an environmental baroclinicity parameter. The optimal predictor categories are shown to be robust across different reanalyses and PL track datasets. The PGI well represents the observed spatial distribution and seasonal cycle of PL genesis frequency and also captures the interannual variability of PL activity skillfully. The effects of the Arctic Oscillation (AO), El Niño-Southern Oscillation (ENSO), and other climate modes on the interannual variability of PL activity are explored, and the application of the PGI to subseasonal to seasonal prediction of PL activity is briefly discussed.
Graduation Semester
2022-05
Type of Resource
Thesis
Copyright and License Information
Copyright 2022 Kevin Boyd

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