Relationships between synoptic-scale atmospheric circulation and ozone concentrations in Metropolitan Pittsburgh, Pennsylvania

Andrew Comrie, Brent Yarnal

Research output: Contribution to journalArticle

92 Scopus citations

Abstract

A synoptic climatology demonstrates the relationships between the atmospheric circulation and surface ozone (O3) concentrations. To deduce these associations, a subjective synoptic classification scheme is applied to 10 years' O3 data from the Pittsburgh metropolitan area. The results focus on four aspects of the atmospheric circulation-O3 relationship: average, extreme-event, between season and year-to year conditions. On average, each of the nine circulation types is related to a characteristic O3 concentration level and cumulative O3 dose. Extreme high-O3 events are associated with either the western side of a slowly migrating anticyclone or a stagnating extended high-pressure ridge; low-O3 events are experienced under cool and cloudy cyclonic conditions. Between-season variations in the average and extreme circulation-O3 relationshipsare observed: the high-pressure features that produce the high st O3 levels in summer are related to low levels in winter, while circulation patterns that contribute very little to summertime O3 build-up are associated with the highest levels of wintertime O3. The latter situation could be caused by tropopause folding and the introduction of stratospheric ozone in winter months. While zonal (meridional) circulation regimes tend to produce lower (higher) mean annual O3 levels, such year-to-year changes in synoptic-type frequencies do not appear to be strongly related to interannual variations in O3, and other non-climatic factors appear to be of greater importance.

Original languageEnglish (US)
Pages (from-to)301-312
Number of pages12
JournalAtmospheric Environment. Part B, Urban Atmosphere
Volume26
Issue number3
DOIs
Publication statusPublished - 1992
Externally publishedYes

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Keywords

  • climate variability
  • Ozone
  • ozone transport
  • synoptic climatology
  • tropospheric ozone
  • weather patterns

ASJC Scopus subject areas

  • Pollution
  • Earth and Planetary Sciences(all)
  • Environmental Science(all)

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