emerging modules for esms: atmospheric chemistry / aerosols
DESCRIPTION
Emerging Modules for ESMs: Atmospheric chemistry / Aerosols. For presentation at the Arctic System Model Workshop III David Plummer. Chemistry effects on climate system. Unlike LLGHGs, ozone and aerosols can have important regional forcings. Antarctic ozone depletion. - PowerPoint PPT PresentationTRANSCRIPT
Emerging Modules for ESMs:Atmospheric chemistry / Aerosols
For presentation at the Arctic System Model Workshop III
David Plummer
Chemistry effects on climate system
• Unlike LLGHGs, ozone and aerosols can have important regional forcings
Antarctic ozone depletion
• trends over 1969-98 for temperature and geopotential height from radiosonde stations in Antarctica– from Thompson and Solomon, Science, 2002
Antarctic ozone depletion
• trends in polar cap temperature (70S to pole) from 2001 to 2050– Figure 1 from Son et al., Science, 2008
Antarctic ozone depletion
• difference in ocean zonal wind stress between runs with and without a prescribed Antarctic ozone depletion– From Lenton et al., GRL,
2009
• decreased uptake of CO2 by 2.3 Pg-C between 1987-2004
Arctic projections
• no ozone hole formation• interaction of ozone with NH
atmospheric circulation much more complex
• active area of research– prescribed, monthly mean vs.
prognostic
• 21st century temperature trends predicted by a suite of different CCMs– From Butchart et al.
(submitted to J. Clim)
Arctic RF
• pre-industrial to present day O3 RF at the tropopause– from Mickley et al. 1999
• black carbon– affects on surface
albedo
Interaction with other ESM components
• experimental evidence for O3 damage to plants– decreased productivity
• Sitch et al. 2007
– low and high sensitivity to O3
• reactive nitrogen (NOx) emitted and oxidized to HNO3
– NO3- deposition = important nutrient
• OH, H2O2, O3 are powerful oxidants– DMS, SO2, VOCs
Likely situation for GCMs in AR5
• several of the large centres have plans to run transient, coupled runs with interactive chemistry– most likely simplified tropospheric chemistry
– prescribed or constrained stratospheric O3
• more consistency in approach to specifying Antarctic ozone trends