9306151 Kritz Because their chemical sources and sinks are negligible and their physical source and removal mechanisms generally well understood, natural and artificial radionuclides have played a unique and valuable role in tracing atmospheric motions and transports. Most recently, with the emergence of global circulation models (GCMs) there has been a growing realization of the important role these radionuclides can play in developing and validating these models, which are a key element in current attempts to understand and model climatic change. However while several current GCMs have incorporated radionuclide such as 222Rn, 210Pb, 7Be and 85Kr, comparing model predictions with observations to evaluate model performance, the application of this approach is severely limited by the absence of a free tropospheric radionuclide data base. This research program is designed to obtain a statistically significant series of summer and winter vertical profiles of 222Rn, and ozone in the mid-latitude northern hemisphere. These profiles, which will extend from the boundary layer to the tropopause will be of considerable value in refining and testing global circulation and climate models. Approximately 16 profiles will be obtained piggybacking aboard the NASA Kuiper Airborne Observatory (KAO), a C-141 aircraft which carries a large infrared telescope. The KAO makes about 100 flights a year, climbing to 41,000 ft to get above the dust and water vapor which would interfere with its astronomical observations. This researcher has been flying measurement-based experiments on the KAO since 1983, and has recently completed construction of a fast sampling system, which is ideal for collecting samples for 222Rn analysis during the normal ascent and descent of this aircraft.
