This title appears in the Scientific Report : 2014 

Inclusion of mountain wave-induced cooling for the formation of PSCs over the Antarctic Peninsula in a chemistry–climate model
Orr, A. (Corresponding Author)
Hosking, J. S. / Hoffmann, L. / Keeble, J. / Dean, S. M. / Roscoe, H. K. / Abraham, N. L. / Vosper, S. / Braesicke, P.
Jülich Supercomputing Center; JSC
Atmospheric chemistry and physics / Discussions, 14 (2014) 12, S. 18277 - 18314
2014
10.5194/acpd-14-18277-2014
Journal Article
Computational Science and Mathematical Methods
OpenAccess
Please use the identifier: http://hdl.handle.net/2128/5822 in citations.
Please use the identifier: http://dx.doi.org/10.5194/acpd-14-18277-2014 in citations.
An important source of polar stratospheric clouds (PSCs), which play a crucial role in controlling polar stratospheric ozone depletion, is from the temperature fluctuations induced by mountain waves. However, this formation mechanism is usually missing in chemistry–climate models because these temperature fluctuations are neither resolved nor parameterised. Here, we investigate the representation of stratospheric mountain wave-induced temperature fluctuations by the UK Met Office Unified Model (UM) at high and low spatial resolution against Atmospheric Infrared Sounder satellite observations for three case studies over the Antarctic Peninsula. At a high horizontal resolution (4 km) the mesoscale configuration of the UM correctly simulates the magnitude, timing, and location of the measured temperature fluctuations. By comparison, at a low horizontal resolution (2.5° × 3.75°) the climate configuration fails to resolve such disturbances. However, it is demonstrated that the temperature fluctuations computed by a mountain wave parameterisation scheme inserted into the climate configuration (which computes the temperature fluctuations due to unresolved mountain waves) are in excellent agreement with the mesoscale configuration responses. The parameterisation was subsequently used to compute the local mountain wave-induced cooling phases in the chemistry–climate configuration of the UM. This increased stratospheric cooling was passed to the PSC scheme of the chemistry–climate model, and caused a 30–50% increase in PSC surface area density over the Antarctic Peninsula compared to a 30 year control simulation.