New Ozone Measurement Systems for Autonomous Operation on Ocean Buoys and Towers*

Abstract

We have built and tested two autonomous ozone measurement systems for use on ocean buoys and towers. They are based on low-power atmospheric ozone sensors from Physical Sciences Inc. (PSI) and 2B Technologies. The PSI sensor operates at 1 Hz with a precision of 1 ppb, but requires about 45 W with the present data system; the 2B makes a measurement every 10 seconds with a precision of 1-2 ppb and uses less than 4 W. The sensors have been packaged in watertight enclosures, with a set of valves and filters to keep out seawater and aerosols. A controller uses data from the sensors and a meteorological system to determine whether sampling should proceed. If a sensor malfunction (such as an incorrect valve position or a temperature beyond its proper range) is detected, the controller attempts to correct it. Both sensors have been tested and used over the ocean, and one complete ozone measurement system (with the PSI sensor) has been successfully deployed on a buoy off Woods Hole. In 2003, this system was operated at the Chesapeake Bay Lighthouse Tower for over a month with excellent results. The2B system was also successfully tested in 2003, at a nearby offshore tower. The design of the systems and their testing and deployments are described, and data from some of the first experiments are presented.

Intercontinental Chemical Transport Experiment Ozonesonde Network Study (IONS) 2004: 2. Tropospheric ozone budgets and variability over northeastern North America

“…Also used are O 3 data measured by a 2B Technologies uv sensor‐based instrument deployed on a buoy operated by Woods Hole Oceanographic Institution [ Hintsa et al , 2004, 2005] at 42.8°N, 70.3°W from 27 June to 6 September 2004. When buoy O 3 was compared to nearby O 3 from the R/V Ronald H. Brown on a couple occasions, agreement was within 2 ppbv.…”

“…The first sailing was 5 -23 July 2004; the second leg was from 26 July to 12 August 2004. The full suite of instrumentation on the R/V Ronald H. Brown appears in Fehsenfeld et al [2006, [11] Also used are O 3 data measured by a 2B Technologies uv sensor-based instrument deployed on a buoy operated by Woods Hole Oceanographic Institution [Hintsa et al, 2004[Hintsa et al, , 2005 [12] In addition to the O 3 , temperature and relative humidity (P-T-U) profiles returned from the sondes, forward and backward air parcel trajectories were run from standard pressure levels at each site. The kinematic version of the Schoeberl and Newman [1995] trajectory model was used with meteorological fields generated from the GEOS-4 version of the GSFC Assimilation Model [Bloom et al, 2005].…”

Higher surface ozone concentrations over the Chesapeake Bay than over the adjacent land: Observations and models from the DISCOVER-AQ and CBODAQ campaigns

“…High levels of ozone are shown only at the lowest levels of the boundary layer, which they attribute to a lack of vertical mixing over the lake (Dye et al, 1995). An experiment in 2003 measured ozone at the Chesapeake Bay Lighthouse, located on an island 15 miles to the east of the entrance to the Chesapeake Bay, as a means to test ozone monitoring on ocean buoys and towers (Hintsa et al, 2004). This field campaign found ozone at the surface consistently exceeding 80 ppbv during an air quality episode from June 24 to 28, 2003.…”

A network of autonomous surface ozone monitors in Antarctica: technical description and first results

“…These instruments are well suited for measurements in remote environments, being small, lightweight, low-powered, and easy to operate (e.g. Hintsa et al, 2004). The units for the autonomous network were further customised as follows.…”