Central California Ozone Study (CCOS) - Desert Research Institute

CCOS Field Operations Plan Version 2: 5/31/00
central California emissions. Interbasin transport sites are intended to evaluate concentrations
along established or potential transport pathways between basins, including the Bay Area, the
North Central Coast Air Basin, the Sacramento Valley, the San Joaquin Valley, Mountain
counties, the South Central Coast Air Basin, and the Mojave desert. Intrabasin gradient sites are
located in non-urban areas between routine network sites. They are intended to evaluate the
extent to which one urban area affects ozone concentrations in another urban area, as well as the
extent to which urban contributions arrive at suburban and rural locations.
2.4.1 Network Design and Measurements
The CCOS field measurement program consists of four categories of supplemental
measurement sites with increasing levels of chemical speciation and time resolution – Type 0, 1,
and 2 “supplemental” (S) sites and “research” (R) sites. Table 2.4-1 lists the measurements
(described in Appendix C) to be made at each of type of supplemental monitoring sites along
with operating period and the groups that are responsible for equipment procurement and testing,
installation and training, and laboratory analysis. The measurement method and specific
instruments that will be used in CCOS are given in Table 2.4-2. This table also provides nominal
precision, detection limit, range, and averaging or sampling times. Tables 2.4-3a, 2.4-3b, and
2.4-3c show the instrument configuration at each of the CCOS supplemental air quality
monitoring sites, using the letter designations introduced in Table 2.4-1. Figure 2.4-1 shows the
locations of the existing monitoring stations measuring ozone and NOx. Figure 2.4-2 shows the
locations of existing monitoring stations measuring carbon monoxide and PAMS speciated
hydrocarbons and carbonyl compounds in relation to proposed CCOS supplemental monitoring
sites. Site descriptions and information (e.g., local contact, mail and shipping addresses, phone
number), equipment installation and operational responsibilities are documented in Appendix
D1. Photographs of the sites are in Appendix D2.
Type 0 supplemental monitoring sites (S0) are intended to fill in key areas of the
modeling domain where ozone and nitrogen oxides are not currently measured. Sites include
McKittrick and Kettleman City (both along the western side of the San Joaquin Valley), Red
Hills (along transport route between San Luis Obispo and the southern San Joaquin Valley),
Lambie Road (in the Sacramento Delta downwind of the Bay Area between Fairfield and Rio
Vista), and Bella Vista (northeast of Redding). Measurements at Bella Vista are designed to
determine whether ozone precursors immediately upwind of Redding are largely transported or
are attributable to local sources. One additional ozone-only site will be established in Shasta
Lake, a resort community about ten miles north of Redding. In addition NO/NOy analyzers will
be added at two existing monitoring sites that currently measure only ozone. These sites are San
Martin (south of the Bay Area between San Jose and Hollister) and Sloughhouse (southeast of
Sacramento).
Type 1 supplemental monitoring sites (S1) are intended to establish boundary and initial
conditions for input into air quality models. These sites are needed at the upwind boundaries of
the modeling domain, in the urban center (initial conditions) and at downwind locations
(boundary conditions). The following aerometric parameters are measured at S1 supplemental
monitoring sites.
1. Continuous surface wind speed and direction and temperature during study period.
Chapter 2: FIELD MEASUREMENTS 2-13