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
The OZWV group conducts several measurement projects at multiple sites around
the world. This page displays a map and listing of the sites.
Column measurements of ozone are made as 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
. At several locations the measurement record is 40
years in length.
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.
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.
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.
Balloon-borne, cryogenic frost point hygrometers are launched
from Boulder, Colorado, Hilo, Hawaii and Lauder, New Zealand to obtain vertical
profiles of water vapor in the upper troposphere and lower stratosphere (to ~30 km).
Water vapor soundings over Boulder (since 1980) provide a unique long-term data record
that may reveal changes in atmospheric dynamics resulting from climate change.