Central California Ozone Study (CCOS) - Desert Research Institute

CCOS Field Operations Plan Version 2: 5/31/00
In addition to releases by T&B Systems, the Naval Air Warfare Center at Pt Mugu will
release several radiosondes with ozonesonde in the Bay Area (Dublin) for comparison with the
Elight ground-base ozone profiler and northern San Joaquin Valley (Tracy or Stockton) during
CCOS IOPs.
In addition to ozonesondes mentioned in the previous section, aloft air quality
measurements are available from fixed platforms that are part of the routine monitoring network
(e.g., Walnut Grove radio tower and Sutter Buttes). CCOS will add NOy and speciated
hydrocarbon measurements at Sutter Buttes to provide additional information on oxidants
available as carry-over to mix-down on the following day.
2.5.3 Ozone LIDAR
The CCOS Technical Committee discussed the merits of using airborne and groundbased
LIDARs to obtain vertical profiles of ozone concentrations, and reached the consensus that
a small fleet of instrumented aircraft would provide a more cost-effective approach given the
tradeoffs between temporal and spatial information and requirements for pollutant flux and
plume measurements. The rationale for the Committee’s recommendation is explained further in
Section 4.8 or the CCOS Field Study Plan. Although ozone LIDAR was not included in the
CCOS Field Study Plan (Fujita et al., 1999), Elight Laser Systems, a German company, will
deploy their commercial Ozone Profiler during CCOS using in-kind resources. The profiler will
be installed in Dublin and will make measurements for one month beginning in early August,
2000.
The Ozone Profiler measure vertical ozone profiles starting at approximately 50 m up to
2000 m with a detection limit of 5µg/m³ with 200 m range resolution. The system can be
delivered as outdoor version with air-water cooling and with water-water cooling as indoor
version. The optics and the electronics are integrated in an outdoors housing which allows
system operation under different weather conditions. In the system a data analysis software
package is implemented for the on-line determination of the ozone concentration as function of
the height. This information can be delivered in form of ASII files or as graphical tables.
Technical specification for the Elight Ozone Profiler is available at their web site at
http://www.elight.de/profiler2.htm.
2.6 In-Situ Aircraft Measurements
Instrumented aircraft will be used to measure the three dimensional distribution of ozone,
ozone precursors, and meteorological variables. For CCOS, aircraft data have five specific uses:
• Aloft boundary and initial conditions – direct input to model.
• Definition of temporal and spatial ozone patterns in layers aloft – model evaluation.
• Direct measurement of mixing depth during spirals – model evaluation and many
corroborative studies.
Chapter 2: FIELD MEASUREMENTS 2-44