The presence of reactive chlorine in the lower troposphere has been postulated in literature but thus far only indirect measurements have been reported. Here we present the first direct observations of chlorine oxide (ClO). During the Vertical Transport and MiXing (VTMX) study in Salt Lake City in October 2000 we observed mixing ratios of 15 ppt ClO and 6 ppt of BrO downwind of salt flats and upwind from the urban area of Salt Lake City. The observed levels lead to a doubling of the atmospheric oxidation capacity. The ozone concentrations observed simulataneously appear to be anticorrelated to the halogen oxide levels, indicating that ozone depletion by catalytic cycles may have occurred.
Revised: April 5, 2005 |
Published: May 15, 2002
Citation
Stutz J., R. Ackerman, J.D. Fast, and L.A. Barrie. 2002.Atmospheric Reactive Chlorine and Bromine at the Great Salt Lake, Utah.Geophysical Research Letters 29, no. 10:1380.PNNL-SA-37406.doi:10.1029/2002GL014812