Detail Spatial considerations in understanding lower atmospheric ozone transport across eastern Phoenix, Arizona Bibliografi Author: Ellis, Andrew W. (Advisor); Hildebrandt, Mark Lincoln ; Balling, Robert C., (Jr.) (Advisor) Topik: PHYSICAL GEOGRAPHY|ENVIRONMENTAL SCIENCES|GEOCHEMISTRY Bahasa: (EN )    ISBN: 0-599-38638-X     Penerbit: Arizona State University     Tahun Terbit: 1999     Jenis: Theses - Dissertation Fulltext: 9937407.pdf (0.0B; 0 download) Abstract Unhealthy levels of ozone across the Phoenix, Arizona (USA) metropolitan area have been a focus of the United States Environmental Protection Agency (EPA), scientists, and local government agencies. As ozone levels exceeding the standard set forth by the EPA occur-within the Phoenix metropolitan area, it has become important to gain an understanding of the mechanisms that transport ozone within Phoenix and its suburbs. The objective of this dissertation is to examine the climatic factors that contributed to the magnitude and spatial distribution of lower atmospheric ozone across the eastern Phoenix Valley in summer 1998. The study is based on the newly mandated ozone exceedance (EPA) of an 8-hour average ozone concentration of 0.08 parts per million (ppm). Forty-three study days were stratified into three categories: high ozone days (O3 ≥ 0.08 ppm), moderate ozone days (0.08 ppm > O3 ≥ 0.07 ppm), and low ozone days (0.07 ppm > O3). The results of this dissertation suggest that a drier atmosphere and resultant high insolation at the surface on days of high ozone were associated with a closely located area of synoptic scale high pressure aloft. The result was warmer ground surface and overlying air temperatures, light winds, increased stability, an apparent lack of turbulent lower atmospheric mixing, and light southwesterly winds at 850 mb that advected little moisture into the area. Also, associated with the light synoptic flow and warm surface conditions on days of high ozone was a wind regime that appeared to be the product of a mesoscale thermodynamic circulation. The daytime flow on high ozone days became directed up the slopes toward the higher elevations of the eastern Phoenix Valley. Embedded within the flow was a plume of high ozone concentrations that extended from an urban area of high ground traffic eastward, into the eastern suburb of Mesa. Conversely, moderate and low ozone days were associated with an eastward displacement of high pressure aloft, greater advection of lowlevel moisture from the south and southeast, smaller insolation receipt, less surface heating, higher instability, and a much-less organized movement of lower atmospheric ozone than on high ozone days. While theoretical studies of ozone transport in complex terrain have been performed (e.g. Berman et al. 1995; Loibi 1997), in situ studies in areas, such as Phoenix, Arizona, are scarce. While some studies have attempted to address the theoretical linkages between meteorological phenomena at multiple spatial scales with ozone transport, no in situ studies have addressed the complex linkages between micro-, meso-, and synoptic scale meteorological processes and ozone transport in Phoenix, Arizona. It is this inter-spatial perspective that is unique to geographic study. This dissertation is a first attempt to address these theoretical processes in situ, and an original search for explanation behind the processes that transport ozone in Phoenix, Arizona. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

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