A new approach to the Brewer-Dobson Circulation: The direct inversion of the continuity equation

The arrows represent two-dimensional circulation vectors as inferred from MIPAS trace gas measurements (left: globally, right: detail). Zonally averaged measurements of CFC-12, CH₄, N₂O und SF₆ were used to invert the continuity equation.

This new approach avoids the problems related to the analysis of the Brewer-Dobson circulation which are: unknown age spectra and mesospheric sinks of the age tracer SF₆. The inversion uses the derivatives of the time-integrated tendency equation with respect to velocities and mixing coefficients and minimizes the residual between the measured and predicted mixing ratio distributions by adjusting the velocities and mixing coefficients.