Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Wuhu Feng and Martyn Chipperfield
NCAS, School of Earth and Environment, University of Leeds, UK
2. TOMCAT/SLIMCAT 3D CTM
4. Computationally Efficient High Resolution Model
4. Arctic ozone depletion
5. Stratospheric vortex edge and atmospheric mixing
Figure 2 (right top panel). Atmospheric mixing is diagnosed as the equivalent length of effective diffusivity. Small (large) values mean weak (strong) mixing
Figure 2 (left panels) . Contours of log -normalized equivalent length of effective diffusivity against the vortex-following PV-equivalent latitude at 493 K (20 km), 456 K (17km) .and 423 K (13 km), respectively. Polar vortex edge is clearly seen around 67oS equivalent latitude. There is strong mixing inside the polar vortex. For details see Roscoe et al. (2012).
Figure 1. Percentage loss of ozone averaged inside the polar vortex (inside 36 PVU contour) at around 18 km for 18 Arctic winters calculated with the TOMCAT/SLIMCAT 3D CTM, updated from Feng et al. (2007). The model shows year-to-year variations of O3 depletion and a record large loss (-85%) in the cold Arctic winter of 2010/11.
6. Inferred total bromine in the atmosphere
7. Impact of solar variation on stratospheric O3 change
Figure 4: Modelled tropical ozone solar signal from satellite data (HALOE, SBUV/SAGE, MLS and SABER) and various SLIMCAT model experiments, for details see Dhomse et al. (2013). The model can reproduce the broad positive ozone anomaly in the middle stratosphere using NRL (A) and SATIRE (B) solar fluxes and ERA-Interim meteorology.
Figure 3: Modelled tropical bromine, for details see Hossaini et al. (2012). Explicit modelling of the sources and chemical sinks of a range of minor bromine compounds shows that VSLS species contribute about 6pptv to stratospheric bromine.