The Ozone and Water Vapor Group conducts research on the nature and causes of the depletion of the stratospheric ozone layer and the role of stratospheric and tropospheric ozone and water vapor in forcing climate change and in modifying the chemical cleansing capacity of the atmosphere. This mission is accomplished through long-term observations and intensive field programs that measure total column ozone, ozone vertical profiles (ozonesondes and umkehrs), ground level ozone, and water vapor vertical profiles in the upper troposphere and stratosphere and through transport modeling with isentropic trajectories.
- Aircraft Measurements - The GMD Tropospheric ozone aircraft measurement program is being done in conjunction with the Carbon Cycle and Greenhouse Gas (CCGG) group's existing aircraft sampling network. Aircraft based in-situ Tropospheric ozone measurements provide data relevant to: pollution events, lower atmosphere mixing dynamics, boundary layer stability, ozone trend studies, and the validity of other samples collected in-flight.
- Atmospheric Transport - An isentropic trajectory model is used to characterize atmospheric transport with an emphasis on understanding the role of transport on the distribution of trace species in the atmosphere. Trajectories for a number of locations can be obtained from this web site.
- Ozonesondes - Ozone profiles are obtained routinely (usually weekly) at eight sites using balloon-borne, electrochemical (ECC) ozonesondes. The profiles provide ozone, temperature, and humidity information from the surface to approximately 32 km. Both stratospheric ozone depletion at the South Pole, and anthropogenic and natural tropospheric ozone changes are studied.
- Stratospheric Aerosols - LIDARS at Mauna Loa and Boulder measure profiles of particles in the troposphere and stratosphere. In the troposphere the particles can result from long range transport from natural or pollution sources. In the stratosphere the particles are primarily volcanic in origin.
- Surface Ozone - Near ground level ozone is currently monitored using ultraviolet absorption photometers at eight sites that are generally representative of background conditions. These sites, four of which have records exceeding 25 years in length, provide information on possible long-term changes in tropospheric ozone near the surface.
- Total Ozone - Column measurements of ozone are made at 15 locations that are part of a global network for detecting and understanding atmospheric ozone change. The Dobson spectrophotometer that makes the total column measurements is also used at six locations to measure ozone profiles using the umkehr technique. At several locations the measurement record is 40 years in length.
- Water Vapor - Balloon-borne, chilled mirror hygrometers are flown monthly at Boulder, Colorado and as part of campaigns at other locations to obtain water vapor profiles in the upper troposphere and lower stratosphere (to ~28 km). The 20-year record at Boulder is a unique record of measurements showing changes in stratospheric water vapor.