The meridional mean circulation in the middle atmosphere, also called Brewer-Dobson circulation (BDC), is the driver of the global distribution of radiatively active trace gases as we observe them. From theory and model simulations we know that the BDC should become faster under global change. Due to its link to atmospheric gases it is important to understand and correctly model the BDC and its temporal change for accurate climate predictions.
In my talk, I will give a short introduction into the BDC. Then I will present observations by MIPAS on Envisat and derived quantities that allow to analyse the BDC during the MIPAS mission period from 2002 to 2012. I will compare the findings from MIPAS with other observations of BDC changes over this period. I will also compare the MIPAS observations with model simulations and resolve a puzzle regarding the differences in observed versus simulated BDC trends. In the last part of my talk I will present a new method to infer more detailed information on the BDC and its variation from a suite of trace gases also measured by MIPAS.