Las Vegas Ozone Study TOPAZ Data
May 30, 2013
May 30. Thursday.
Clear skies, but quite hazy in the valley. A few contrails and Cirrus clouds to the east. Light upslope flow from the E/NE, which transported urban air to the Angel Peak site starting around 1200 PDT. Lidar data was collected from 1100 to 1945 PDT. The lidar data show an increase of O3 in the lowest few hundred meters AGL from the low 60s to the low/mid 80s ppbv, reflecting the transport of the Las Vegas urban plume to Angel Peak in the afternoon. A layer of elevated O3 above 1500 m AGL appears to have merged with the urban plume in the afternoon. The surface in situ observations also show the arrival of the Las Vegas urban plume. O3 and CO values increased from 62/119 ppbv in the late morning to 83/150 in the afternoon. The Joe Neal O3 monitoring site in the valley measured a peak 1-hour value of 79 ppbv. Surface O3 values at Angel Peak stayed at about 80 ppbv into the evening, while CO dropped to about 130 ppbv.
Note: These preliminary data are noisy near the top of the curtain plot and exhibit a low bias around noon and in the early afternoon due to the solar background.
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