Effect of local radiative forcing on upper tropospheric jet characteristics

Upper tropospheric jets play a key role in the climate system, determining storm-track dynamics and surface weather, including precipitation. While their structure is primarily determined dynamically, the strong latitudinal gradients in key radiative species, such as ozone, water vapour, and aerosol, across the jet feed back on jet characteristics including strength, variability, stability and location. However these cross-jet gradients have never been properly quantified. It is therefore not known whether they might be a contributing factor to the systematic biases in jet location and strength that are widespread in current climate models. This project aims at the quantification of the climatology and variability in cross-jet tracer gradients and their radiative impact using aircraft and newly available global satellite observations in a recently established coordinate system that takes into account the position of the measurements relative to the jet in latitude and altitude. Transport processes across the tropopause that impact these tracer gradients will also be studied in relation to the jets. The results will then allow for rigorous testing of jet characteristics in climate (and weather forecast) models.

Further details of the project can be found at
http://www.met.reading.ac.uk/pg-research/Hegglin.pdf

General information on the PhD programme at the Department of Meteorology can be found at
http://www.met.reading.ac.uk/pg-research/