[摘要] The Match method quantifies chemical ozone loss in the polar stratosphere.The basic idea consists in calculating the forward trajectory of an air parcelthat has been probed by an ozone measurement (e.g., by an ozonesonde orsatellite instrument) and finding a second ozone measurement close to thistrajectory.Such an event is called a "match".A rate of chemical ozone destruction can be obtained by a statistical analysisof several tens of such match events.Information on the uncertainty of the calculated rate can be inferred from thescatter of the ozone mixing ratio difference (second measurement minus firstmeasurement) associated with individual matches.A standard analysis would assume that the errors of these differences arestatistically independent.However, this assumption may be violated because different matches can share acommon ozone measurement, so that the errors associated with thesematch events become statistically dependent.Taking this effect into account, we present an analysis of the uncertaintyof the final Match result.It has been applied to Match data from the Arctic winters 1995, 1996, 2000, and2003.For these ozonesonde Match studies the effect of the error correlation on theuncertainty estimates is rather small:compared to a standard error analysis, the uncertainty estimates increase by15% on average.However, the effect may be more pronounced for typical satellite Match analyses:for an Antarctic satellite Match study (2003), the uncertainty estimatesincrease by 60% on average.
The analysis showed that the random errors of the ozone measurements and the"net match errors", which result from a displacement of the second ozonemeasurement of a match from the requiredposition, are of similar magnitude.This demonstrates that the criteria for accepting a match (maximum trajectoryduration, match radius, spread of trajectory clusters etc.) ensure that, giventhe unavoidable ozone-measurement errors, the magnitude of the net match errorsis adequate.The estimate of the random errors of the ozonesonde measurements agrees wellwith laboratory results.
