FAST-LVOS 2017 TOPAZ Data
June 28, 2017
Wednesday, June 28
TOPAZ data were recorded from 09:19 - 22:47 PDT. Normal temperatures today (max. of 42 C at the lidar site) and 106 F at the NLVA NWS tower. Severe clear skies all day, with haze/smoke below 2 km that was transported from the SJV during the night. The winds were generally light, but followed the usual pattern of morning northwesterlies, week mid-day southwesterlies, and stronger (10 m/s) evening westerlies. The nocturnal low-level transport from the SJV also led to relatively high ozone at Jean and several other CC sites during the night. A residual layer containing this transported ozone was entrained by 1000 PDT, increasing the surface concentrations at NLVA to about 65 ppbv. A narrow layer of predominantly UT/LS origin with high (100-120 ppbv) ozone, and some aerosol consistent with mixing of pollution or fire plumes from Asia, descended from 4 km asl at 0920 PDT to 3 km asl at 1400 PDT, when it was entrained by the ML, which grew to about 3.6 km agl. This helped increase the surface concentrations at NLVA to a peak of about 80 ppbv. Peak hourly concentrations in excess of 70 ppbv were measured at 8 of the CC regulatory monitors, with the 2015 NAAQS of 70 ppbv exceeded at Joe Neal (74 ppbv) and Apex (71 ppbv).
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