Interannual Variability of Long-Lived Trace Gas Transport from the Middle Stratosphere to the Surface

We have recently shown that variability in long-lived surface trace gas measurements on one to five-year time scales is often well correlated with the stratospheric QBO. This variability is important to account for in the calculation of annual emissions of trace gases such as CFC-11 from global-scale atmospheric concentrations, and also points out an interesting connection between stratospheric and tropospheric transport variability. WACCM simulations with a nudged QBO reveal a coherent propagation of trace gas anomalies from the middle stratosphere to the surface, driven by QBO modulation of the residual mean circulation. In this work we examine interannual variability in trace gas measurements from the stratosphere to the troposphere from the MLS, TES and ACE instruments as well as the NOAA surface network, and how they compare to the WACCM simulated trace gas variability. The now extensive satellite measurement record allows us to compare the measured vs. modeled variability over a number of QBO cycles with different seasonal and ENSO phasing. The combination of satellite and surface measurements provide a powerful constraint on the modeled trace gas transport throughout the stratosphere and troposphere.