WGCM Chemistry

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SPARC and ACC/SPARC Ozone Database for CMIP5
Veronika Eyring (DLR) and Ted Shepherd (Univ. of
Toronto)
13th Session of the JSC/CLIVAR Working Group on
Coupled Modelling (WGCM) San Francisco, 28-30
September 2009
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Stratospheric Processes And their Role in Climate
(SPARC) 1. Model Evaluation
Chemistry-Climate Model Validation Activity
(CCMVal) Coordination Veronika Eyring, Darryn
Waugh, Ted Shepherd, Andrew Gettelman, Steven
Pawson GOAL Improve understanding of CCMs
through process-oriented evaluation and provide
reliable projections of stratospheric ozone and
its impact on climate
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CCMVal approach to CCM Evaluation and analysis
Eyring et al., BAMS, 2005
CCMVal Evaluation Table (core processes,
diagnostics, variables, observations)
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CCMVal-1 Ozone Projections 13 CCMs in support of
WMO/UNEP 2006 and IPCC AR4
Eyring et al., JGR, 2006, 2007
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SPARC CCMVal Report on Evaluation of CCMs 18
CCMs in support of WMO/UNEP 2010 and IPCC AR5

• In the past there has been insufficient time to
  evaluate CCM performance thoroughly while
  preparing the Ozone Assessments.
• The goal of the SPARC CCMVal report is to provide
  useful and timely information for the WMO/UNEP
  2010 IPCC AR5 and an up-to-date evaluation of
  CCMs, a reassessment of the projections of ozone
  and UV radiation through the 21st century, and
  the impact of stratospheric changes on climate.
• Structure and Authors (around 100 authors are
  analyzing the CCMVal-2 data)
• Executive Summary Eyring, Shepherd, Waugh plus
  chapter Lead Authors
• Chapter 1 Introduction Eyring, Shepherd,
  Waugh
• Part A Chapter 2 Chemistry Climate Models and
  Scenarios Morgenstern, Giorgetta, Shibata
• Part B Process evaluation
• Chapter 3 Radiation Fomichev, Forster
• Chapter 4 Dynamics Butchart, Charlton
• Chapter 5 Transport Neu, Strahan
• Chapter 6 Chemistry and microphysics
  Chipperfield, Kinnison
• Chapter 7 UTLS Gettelman, Hegglin
• Part C Chemistry-Climate Coupling
• Chapter 8 Natural Variability Manzini, Matthes
• Chapter 9 Long-term Projection of Stratospheric
  Ozone Austin, Scinocca
• Chapter 10 Effect of the Stratosphere on Climate
  Baldwin, Gillett
• Timelines Currently under final external review,
  published Jan-March 2010 JGR Special Issue
• CCMVal diagnostic tool is developed based on the
  CCMVal evaluation table Eyring et al., BAMS,
  2005 to ensure progress in model evaluation from
  one to the next round (e.g. CCMVal-1 to -2)

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Earth System-Model Validation
talk by Pierre on Wed (WGCM/AIMES meeting)
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II. ACC / SPARC Ozone Database Effect of
stratospheric ozone on climate

• Ozone hole has led to a strengthening of the
  summertime surface westerlies at SH high
  latitudes Thompson and Solomon, 2002.
• Ozone recovery is predicted to reverse that
  trend, with implications for the circulation of
  the southern ocean Son et al., 2008.
• Effects of O3 depletion/recovery also in many
  other climate indicators showing its global
  impact.
• CMIP3 models without any prescribed ozone changes
  (green), the past and future trends are the same
  whereas for models with prescribed ozone
  depletion (red) and ozone recovery (blue).
• gt Need accurate representation of ozone recovery
  in climate projections.

DJF
Oct-Jan
DJF
DJF
Son et al., GRL, 2009
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ACC / SPARC Ozone Data Sets for CMIP5
Goal Provide a merged tropospheric /
stratospheric ozone time series from 1850 to 2100
for use in CMIP5 simulations without interactive
chemistry. I. Cionni V. Eyring (DLR), JF.
Lamarque B. Randel (NCAR)

• Historical Database (1850-2009) CF netCDF
  monthly-mean lon, lat, pressure, timemonth
• Stratospheric data (Zonal means)
• Multiple linear regression analysis of SAGE III
  satellite observations and polar ozonesonde
  measurements for the period 1979-2005 (Randel and
  Wu, JGR, 2007).
• Regression includes terms representing equivalent
  effective stratospheric chlorine (EESC) and
  11-year solar cycle variability.
• Extended backwards to 1850 based on the
  regression fits combined with extended proxy
  times series of EESC and solar variability.
• Tropospheric data (3D but decadal averages)
• Average from the Community Atmosphere Model (CAM)
  version 3.5 and the NASA-GISS PUCCINI model.
• Both models simulate tropospheric and
  stratospheric chemistry with feedback to the
  radiation and were driven by the recently
  available historical (1850-2000) emissions
  succintly described in Lamarque et al., IGAC
  Newsletter, May 2009.
• Combined stratospheric / tropospheric data (3D
  but underlying zonal mean in stratosphere)
• S and T are combined by merging the two data sets
  across the climatological tropopause, to produce
  a smooth final data set.
• FINAL VERSION RELEASED ON 22 SEP 2009 (see CMIP5
  website, 16 files a 30 MB)

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ACC / SPARC Ozone Data Sets for CMIP5 A.
Historical Database (1850-2009) see more plots at
http//www.pa.op.dlr.de/CCMVal/ACCSPARC_O3Databas
e_CMIP5.html
Cionni et al., in prep, 2009
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ACC / SPARC Ozone Data Sets for CMIP5

• Future Database (2010-2099)
• Stratosphere multi-model CCMVal-2 mean
• Troposphere Community Atmosphere Model (CAM)
  version 3.5
• The data from the observational core and the
  model time series are combined separately for
  each latitude band and pressure level using a
  linear regression model.
• Combined Ozone Timeseries (1850 to 2100)

Cionni et al., in prep, 2009
Austin, Scinocca et al., Chapter 9, SPARC CCMVal
Report, 2009
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Summary and Recommendations

• Recommendation for models that do not have
  interactive chemistry prescribe ozone according
  to the new SPARC/ACC ozone time series for
  consistency.
• Advocacy of 'best practice' in modeling as
  including physically-based, self-consistent
  representations of key processes, e.g.
• e.g. a unified representation of tropospheric and
  stratospheric chemistry in CCMs, to remove
  inconsistencies in models with relaxation of
  chemical constituents to prescribed values
  Stevenson, Nature Geosci 2009, CCM runs with
  coupled ocean for chemistry-climate interactions
  studies.
• Support for process-oriented model evaluation
  activities (such as CCMVal, C4MIP, CFMIP) in
  close conjunction with improved measurements
  similar efforts for coupled ESMs (ESMVal) Eyring
  et al., BAMS, 2005 2009 in prep..
• Support for central software for the analysis of
  climate and Earth system models
• Development of performance metrics for the
  documentation of model improvements, improved
  process studies and projections Gleckler et al.,
  JGR, 2008 Reichler Kim, BAMS, 2008 Waugh
  Eyring, ACP, 2008 Santer et al., PNAS, 2009

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II. Effect of climate change on stratospheric
ozone, STE and UV index

• Climate-induced stratospheric circulation changes
  are predicted to have a significant effect on the
  evolution of stratospheric ozone in the 21st
  century
• Has impacts for stratosphere-to-troposphere ozone
  flux (left) and clear-sky UV index (right)
• Points to need for unified stratosphere-tropospher
  e CCMs Stevenson, Nature Geosci, 2009

Hegglin Shepherd, Nature Geosci, 2009
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Trop. Jet Comparison CCMVal with AR4
modelsCCMVal models have fully interactive
stratospheric chemistry
2000-2050 trend in Zonal Wind

• Owing to the disappearance of the ozone hole in
  the first half of the 21st century (Eyring et
  al., 2007 WMO, 2007)
• Deceleration poleward side of jet (decrease in
  SAM) found in multi-CCM mean.
• Opposite response in mean of IPCC AR4
  simulations.
• Importance of ozone can be seen by comparing AR4
  models with without ozone recovery.
• Weaker response in AR4 models with O3 recovery.

CCMs
AR4
No recovery
O3 recovery
Son et al., Science, 2008 see also Perlwitz et
al., GRL, 2008
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Testing impact of interactive chemistry
2000-2050 trend in Zonal Wind
CCM
1. GEOSCCM REF2 run. 2. GCM run with
monthly-mean zonal-mean O3 from CCM REF2 run.
Response in GCM is weaker than CCM, with
difference similar to CCM vrs AR4 with recovery.
CCMs
AR4
GCM
No recovery
O3 recovery
Courtesy of Luke Oman (JHU)