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Progress on the 2010 WMO/UNEP ozone assessment. Greg Bodeker. Presented at SPARC-SSG meeting, Kyoto, Japan 27 October 2009. 2010 Ozone Assessment Co-chairs. Ayité - Lô Ajavon (Togo ) Paul Newman (USA) John Pyle ( UK) A.R . Ravishankara (USA).
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Progress on the 2010 WMO/UNEP ozone assessment Greg Bodeker Presented at SPARC-SSG meeting, Kyoto, Japan 27 October 2009
2010 Ozone Assessment Co-chairs Ayité-LôAjavon (Togo) Paul Newman (USA) John Pyle (UK) A.R. Ravishankara (USA) Scientific Assessment of Ozone Depletion:2010 Colour? 2006 Assessment 2010 Assessment
The Parties’ Request (Decision XIX/20) • Assess the state of the ozone layer and its future evolution • Evaluate recent Antarctic ozone hole and Arctic ozone depletion behavior • Evaluate trends of ozone-depleting substances in the atmosphere • Assess the impacts of climate change on ozone layer • Analyze atmospheric concentrations of bromine and implications for the ozone-layer • Describe surface ultraviolet radiation observations and future expectations • Assess interaction between tropospheric and stratospheric ozone • Assess approaches to evaluating very short-lived substances
2010 Ozone Assessment Structure New level of authorship in this assessment: Co-ordinating Lead Authors (CLAs), Lead Authors (LAs), Co-authors (CAs), and contributing authors – some resultant confusion. Chapter 1: Ozone-Depleting Substances and Related Chemicals – Steve Montzka and Stefan Reimann Chapter 2: Stratospheric Ozone and Surface Ultraviolet Radiation – Anne Douglass and VitaliFioletov Chapter 3: Future Ozone and its Impact on Surface UV – SlimaneBekki and Greg Bodeker Chapter 4: Stratospheric Change and Climate – Piers Forster and Dave Thompson Chapter 5: Information and Options for Policymakers – John Daniel and GuusVelders Twenty Questions and Answers About the Ozone Layer: 2010 Update – David Fahey and Michaela Hegglin
Where we are • Draft outline completed. Comments solicited from scientific community. • Coordinating Lead Authors & author teams established. Chapter outlines drafted. • June 24-25, 2009: Lead Authors’ meeting (London) • 13 October: 1st drafts due; circulated for internal review. • November 17-19, 2009: Internal review meeting: Coordinating Lead Authors, Cochairs, and a few others. (Washington, DC) • 18 February 2010: 2nd drafts complete and mail peer review starts. • April: mail reviews due; third draft preparation begins. • Mid-May: Third draft due; distributed to Les Diablerets Panel reviewers. • June 28 - July 2, 2010: Panel Review: (Les Diablerets, Switzerland) • Coodinating Lead Authors & a few Lead Authors. • ~30-40 reviewers. • Final decisions on chapters. • Completed Executive Summary. • Early August: Chapters completed, editing begins. • 30 December: preprint volume to UNEP for government distribution. • ~ March 2011: final printed copies available 2009 2010
Main Issues (1 of 3) • First assessment to consider the effects of stratospheric change on climate. This is a key SPARC connection. • The 2006 ozone assessment had to do CCM validation on the fly. Now the SPARC CCMValReport on the Evaluation of Chemistry-Climate Models is available. • Advantages: huge amount of work that can be built off. • Disadvantages: work overload from potential authors, need to define the distinction between the reports. • Report on the resolution of the Pope et al. Cl2O2 UV absorption cross-section measurements. • More refined analysis of the impact of climate change on ozone recovery. • Effects of geoengineering on ozone. • Availability of sensitivity simulations from CCMVal.
Main Issues (2 of 3) • Still plenty of discussion about the role of Very Short Lived Substances (VSLS) on the total halogen burden of the stratosphere. • N2O as a major future chemical influence on ozone. • UV no longer has its own chapter. • Need for incorporation of interactive ocean in CCMs. • Recent increases in stratospheric aerosol burden from large increases in Chinese coal-fired power stations. • Changes in the strength of the Brewer-Dobson circulation. • Fixed volume mixing ratio boundary condition in CCMs. • Reporting on ‘World Avoided’ scenarios. • Effects of changes in stratospheric water vapour on climate.
Main Issues (3 of 3) • Changes in stratospheric volcanic aerosol loading have prolonged effects on surface climate. • Updated reporting on stratospheric temperature trends. • Effects of changes in the SAM on surface climate over southern middle and high latitudes. • Update on ODPs and GWPs for many ODSs. • Discussion of the effects of accelerated phase out of HCFCs. • The role that the Montreal Protocol has played in mitigating climate change – but potential future growth of HFCs may offset any gains.
Lessons for SPARC • Where possible, SPARC special reports feeding ozone or IPCC assessments should be completed before the beginning of the assessment process. • SPARC research is becoming increasingly central to WMO/UNEP ozone assessments. Slow shift in emphasis away from ‘QOS’ and towards ‘SPARC’. • The SPARC special report on CCM validation has been incredibly valuable to the 2010 ozone assessment. Any plans for SPARC’s role in guiding CCMVal-3 and how that will feed the 2014 ozone assessment?