Monday, June 12
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TOPAZ data were recorded from 7:44 PDT through the night until 6:32 PDT on June 13 (data collection was continued the next day without interruption). Cool temperatures (max. of 29 C) and clear conditions. Decreasing winds in the morning and then light winds veering from SW to NW during the remainder of the day in the wake of the departing trough. Very high ozone was observed above 5 km AGL (max. ozone values near 280 ppbv in the morning) with several ozone filaments descending to about 3 km AGL. The ML was not deep enough to entrain any of this ozone. Surface ozone stayed below 50 ppbv in the cool post-frontal conditions.