The <i>Fires, Asian, and Stratospheric Transport</i>–Las Vegas Ozone Study (<i>FAST</i>-LVOS)
<p><span id="page1708"/>The <i>Fires, Asian, and Stratospheric Transport</i>–Las Vegas Ozone Study (<i>FAST</i>-LVOS) was conducted in May and June of 2017 to study the transport of ozone (O<span class="inline-formula"><sub>3</su...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-02-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/1707/2022/acp-22-1707-2022.pdf |
| Summary: | <p><span id="page1708"/>The <i>Fires, Asian, and Stratospheric Transport</i>–Las Vegas Ozone Study (<i>FAST</i>-LVOS) was conducted in May and June of 2017 to
study the transport of ozone (O<span class="inline-formula"><sub>3</sub></span>) to Clark County, Nevada, a marginal
non-attainment area in the southwestern United States (SWUS). This 6-week (20 May–30 June 2017) field campaign used lidar, ozonesonde, aircraft, and
in situ measurements in conjunction with a variety of models to characterize
the distribution of O<span class="inline-formula"><sub>3</sub></span> and related species above southern Nevada and
neighboring California and to probe the influence of stratospheric
intrusions and wildfires as well as local, regional, and Asian pollution on surface
O<span class="inline-formula"><sub>3</sub></span> concentrations in the Las Vegas Valley (<span class="inline-formula">≈</span> 900 m above sea level, a.s.l.). In this paper, we describe the <i>FAST</i>-LVOS campaign and present
case studies illustrating the influence of different transport processes on
background O<span class="inline-formula"><sub>3</sub></span> in Clark County and southern Nevada. The companion paper
by Zhang et al. (2020) describes the use of the AM4 and GEOS-Chem global
models to simulate the measurements and estimate the impacts of transported
O<span class="inline-formula"><sub>3</sub></span> on surface air quality across the greater southwestern US and
Intermountain West. The <i>FAST</i>-LVOS measurements found elevated O<span class="inline-formula"><sub>3</sub></span> layers above Las Vegas on more than 75 % (35 of 45) of the sample days and show that entrainment of these layers contributed to mean 8 h average regional
background O<span class="inline-formula"><sub>3</sub></span> concentrations of 50–55 parts per billion by volume
(ppbv), or about 85–95 <span class="inline-formula">µ</span>g m<span class="inline-formula"><sup>−3</sup></span>. These high background
concentrations constitute 70 %–80 % of the current US National Ambient Air Quality Standard (NAAQS) of 70 ppbv (<span class="inline-formula">≈</span> 120 <span class="inline-formula">µ</span>g m<span class="inline-formula"><sup>−3</sup></span> at 900 m a.s.l.) for the daily maximum 8 h average (MDA8) and will make attainment of the more stringent standards of 60 or 65 ppbv currently being considered
extremely difficult in the interior SWUS.</p> |
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| ISSN: | 1680-7316 1680-7324 |