Structure and processes of the upper troposphere and lower stratosphere, and their sensitivity to changes in atmospheric CO2 concentrations
Lead Research Organisation:
University of Cambridge
Department Name: Applied Maths and Theoretical Physics
Abstract
The separation of troposphere and stratosphere is traditionally based on criteria of the vertical temperature structure, with a sharp tropopause at an altitude of about 10 km, that bulges steeply upward over the subtropics to an altitude of about 17 km over the tropics. However, other characteristics such as radiative properties or correlations of trace gas concentrations suggest a more gradual transition over a vertical layer extending from the upper troposphere (UT) into the lower stratosphere (LS). The structure of the UT/LS is determined both by tropospheric and stratospheric processes, and may be sensitive to changes in atmospheric carbon dioxide concentrations. Conversely, changes in the UT/LS may have a strong feedback on climate. The proposed project will help to improve our understanding of the processes that control the UT/LS structure in order to provide improved predictions of how this layer changes in a changing climate, and how the changes in this layer may have an impact on climate. To this end, we will make use of space-borne atmospheric observations, as well as of in-situ observations from instruments onboard of high flying aircrafts. The analysis of these observations will help to formulate hypotheses, which will be tested with the help of large-scale numerical models, ranging in complexity from primitive equation models to coupled chemistry/climate models.
Organisations
People |
ORCID iD |
Stephan Fueglistaler (Principal Investigator) |
Publications
Dessler A
(2007)
Effects of convective ice lofting on H 2 O and HDO in the tropical tropopause layer
in Journal of Geophysical Research: Atmospheres
Flannaghan T
(2011)
Kelvin waves and shear-flow turbulent mixing in the TTL in (re-)analysis data TTL MIXING
in Geophysical Research Letters
Folkins I
(2008)
A Low-Level Circulation in the Tropics
in Journal of the Atmospheric Sciences
Fueglistaler S
(2011)
The annual cycle in lower stratospheric temperatures revisited
in Atmospheric Chemistry and Physics
James R
(2008)
Water vapor transport and dehydration above convective outflow during Asian monsoon
in Geophysical Research Letters
Ploeger F
(2011)
Insight from ozone and water vapour on transport in the tropical tropopause layer (TTL)
in Atmospheric Chemistry and Physics
Schofield R
(2011)
Sensitivity of stratospheric Br<sub>y</sub> to uncertainties in very short lived substance emissions and atmospheric transport
in Atmospheric Chemistry and Physics
Wright J
(2011)
The influence of summertime convection over Southeast Asia on water vapor in the tropical stratosphere
in Journal of Geophysical Research