Central California Ozone Study (CCOS) - Desert Research Institute
Central California Ozone Study (CCOS) - Desert Research Institute
Central California Ozone Study (CCOS) - Desert Research Institute
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<strong>CCOS</strong> Field Operations Plan Version 2: 5/31/00<br />
Data Comparisons: Coordinate parallel flight with other aircraft as desired. TVA onboard<br />
calibrator can be used to intercompare with other aircraft when at the same airport.<br />
Flight Plans:<br />
Flight air speed will be near 125 kts for ferries and near 95 kts for plume traversing. Ferries will<br />
also provide detailed gaseous speciation. Start time may be adjusted depending on expected<br />
plume transport speed.<br />
(1) Power Plant Mission: At 1100 PDT ferry from Livermore to target plant (Pittsburg or<br />
Moss Landing) at mid boundary layer. Spiral from minimum safe altitude to 5000’ 5 km<br />
upwind of plant for upwind vertical profile. Circle plant at 5 km to establish actual plume<br />
centerline direction and for first traverse. Continue a series of plume traverses at mid<br />
boundary level at 5 km spacing out to distance where ozone chemistry has finished or<br />
plume is indistinguishable from background. Spacing of lagrangian plume traverses will<br />
be fixed for a given flight and set based on profiler mid boundary layer wind at flight<br />
time. Length of traverses will be adjusted in flight depending on horizontal mixing<br />
observed in real time. Downwind spiral to 5000’ will be performed when last traverse<br />
completed. Ferry back to Livermore airport at completion.<br />
(2) Supplemental Mission: As time and existing budget permits TVA Twin Otter may add<br />
regional survey legs to power plant missions to enhance data in the Livermore Valley,<br />
Sacramento Valley or SJV as desired for clusters 1, 2, or 3 to increase detail and<br />
parameters measured by collaborating aircraft. Basing at Livermore should permit<br />
efficient add-ons. Detailed NOy speciation can greatly improve knowledge of chemical<br />
age and processing of ozone rich airmasses. Supplemental missions will be coordinated at<br />
daily planning sessions.<br />
Objectives and Rationale: Map detailed ozone, precursor, and products in power plant plumes<br />
and in regional airmasses during ferries and supplemental add-ons.<br />
2.6.7 VOC Sample Collection Methods and Protocols<br />
Hydrocarbon samples are collected in stainless steel canisters and will be analyzed for C 1<br />
to C 11 hydrocarbons, CO and CO 2 at Biospheric <strong>Research</strong> Corporation (Beaverton, OR) by gas<br />
chromatography with flame ionization detection. The aircraft samplers will be supplied by BRC.<br />
They will operate manually off 24-48 volts and be configured to collect 3.2 liters canisters over<br />
averaging times of several minutes to near instantaneous.<br />
Carbonyl samples are collected in Tedlar bags and transferred to dinitrophenyl hydrazine<br />
impregnated cartridges on the ground at the conclusion of the flight. Samples will be collected<br />
by ramming air through a Telfon inlet tube into pre-cleaned 40-liter Tedlar bags that had been<br />
doped with excess NO to react with any O 3 in the air sample. Sampling times are approximately<br />
2-5 minutes. The stainless steel valves attached to the Teflon bags are specially modified to<br />
permit rapid filling and all rubber seals have been replaced with inert Viton parts. Because the<br />
sample sizes for the aloft carbonyl samples (nominally 30 liters) are substantially less than for a<br />
typical surface sample, additional efforts are necessary to reduce blank variability in order to<br />
Chapter 2: FIELD MEASUREMENTS 2-72
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