September 27. Friday.
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Last day of DiscoverAQ measurements. TOPAZ data were collected from about 1135 to 1700 CDT. Later start time of obs was due to TOPAZ system maintenance and laser tuneup. Partly cloudy in the morning, becoming mostly cloudy in the afternoon. Cloud bases lowering to 1000 m AGL at times. ESEerly winds, light early in the morning, strengthening by mid morning. Surface O3 values around 40 ppbv early, increasing into the 60s ppbv by late morning. O3 was well mixed up to about 800-1000 m AGL and held steady in the 60s ppbv throughout the afternoon.
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Note: Biases due to clouds have not yet been fully corrected.