A Cost-Effective Trace Gas Measurement Program for Long-Term Monitoring of the Stratospheric Circulation

摘要

A stratospheric trace gas measurement program using balloon-based sonde and AirCore sampler techniques is proposed as a way to monitor the strength of the stratospheric mean meridional or Brewer-Dobson circulation. Modeling work predicts a strengthening of the Brewer-Dobson circulation in response to increasing greenhouse gas concentrations; such a change will likely impact tropospheric climate. Because the strength of the Brewer-Dobson circulation is an unmeasureable quantity, trace gas measurements are used to infer characteristics of the circulation. At present, stratospheric trace gas measurements are sporadic in time and/or place, primarily associated with localized aircraft or balloon campaigns or relatively short-lived satellite instruments. This program would consist of regular trace gas profile measurements taken at multiple latitudes covering tropical, midlatitude, and polar regimes. The program would make use of the relatively low-cost AirCore and sonde techniques, allowing more frequent measurements given the significantly lower cost than with current techniques. The program will provide a means of monitoring changes in the strength and redistribution of the stratospheric circulation. The goals are to monitor the strength of the Brewer-Dobson circulation and to improve understanding of the reasons for stratospheric circulation changes, ultimately resulting in more realistic model predictions of climate change for the coming decades.