WGCM Chemistry - PowerPoint PPT Presentation

1 / 12
About This Presentation
Title:

WGCM Chemistry

Description:

Veronika Eyring (DLR) and Ted Shepherd (Univ. of Toronto) 13th Session of the JSC/CLIVAR ... Trop. Jet: Comparison CCMVal with AR4 models ... – PowerPoint PPT presentation

Number of Views:35
Avg rating:3.0/5.0
Slides: 13
Provided by: veronik1
Category:
Tags: wgcm | chemistry | de | trop

less

Transcript and Presenter's Notes

Title: WGCM Chemistry


1
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
2
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
3
CCMVal approach to CCM Evaluation and analysis
Eyring et al., BAMS, 2005
CCMVal Evaluation Table (core processes,
diagnostics, variables, observations)
4
CCMVal-1 Ozone Projections 13 CCMs in support of
WMO/UNEP 2006 and IPCC AR4
Eyring et al., JGR, 2006, 2007
5
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)

6
Earth System-Model Validation
talk by Pierre on Wed (WGCM/AIMES meeting)
7
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
8
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)

9
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
10
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
11
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

12
(No Transcript)
13
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
14
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
15
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)
Write a Comment
User Comments (0)
About PowerShow.com