Temperature trends in the upper troposphere/ lower stratosphere as revealed by CCMs and AOGCMs

Eugene Cordero, Sium TesfaiDepartment of Meteorology San Jose State University, USA

Veronika EyringDLR Institute for Physics of the Atmosphere, Germany

Neal Butchart Climate Research Division, Met Office, UK

OutlineGoals and Motivation

20th century

21st century

Aim: To determine if systematic differences exist between AOGCMs and CCMs simulations during the 20th and 21st centuries.

Questions:

§ Are CCM’s better able to simulate the 20th century atmosphere compared to AOGCM models?

§ What effect does ozone forcing have on temperature trends in the stratosphere and troposphere?

§ How will the SRES emission scenarios affect O3 recovery?

AOGCM Simulations (IPCC 2007) AOGCM Simulations (IPCC 2007)

Coupled Atmosphere – Ocean General Circulation Models (AOGCMs) - IPCC AR4 (CMIP3)

Simulations from 17 international research groups (23 model simulations)

Variety of emission scenarios– 20th century– 21st century - various scenarios

Model focus is on surface and troposphere

Cordero and Forster, 2006: Stratospheric variability and trends in

models used for the IPCC AR4, ACP.

CCM Simulations (WMO/UNEP 2006) CCM Simulations (WMO/UNEP 2006) Coupled Chemistry Climate Models (CCM) Simulations from 13 international research groups Two primary sets of simulations

– 20th century (REF1)

– 21st century (REF2) Model focus is primarily on evolution of the ozone

layer.

Eyring et al., 2006: Assessment of temperature, trace species, and ozone in chemistry climate model simulations of the recent past, JGR.

Eyring et al., 2007: Multimodel projections of stratospheric ozone

in the 21st century, JGR

Coupled Chemistry-Climate Models (CCMs)

AOGCM Model Forcings

Cordero and Forster, 2006

Model GHG Volcanic Ozone Solar Z-top S-lev Model top

BCCR-BCM2.0 Y N N N 33 5 Low

CCSM3 Y Y Y Y 40 7 Low

CGCM3.1(T47) Y N Nb ? 49 11 High

CNRM-CM3 Y N Nb N 76 17 High

CSIRO-Mk3.0 Y Na Y N 38 3 Low

ECHAM5/MPI-OM Y N Y ? 29 4 Low

FGOALS-g1.0 Y N Nb Y 45 9 High

GFDL-CM2.0 Y Y Y Y 35 3 Low

GFDL-CM2.1 Y Y Y Y 35 3 Low

GISS-AOM Y N N N 33 3 Low

GISS-EH Y Y Y Y 67 9 High

GISS-ER Y Y Y Y 67 9 High

INM-CM3.0 Y Na N N 32 6 Low

IPSL-CM4 Y N N N 32 7 Low

MIROC3.2(hires) Y Y Y Y 45 19 High

MIROC3.2(medres) Y Y Y Y 67 6 High

MRI-CGCM2.3.2 Y Na N Y 54 8 High

PCM Y Y Y Y 43 7 Low

UKMO-HadCM3 Y N Y ? 39 5 Low

Model Group and location Horiz. resolution

Vertical Layers /Upper Boundary

AMTRAC GFDL, USA 2° x 2.5° 48 L / 0.0017 hPa

CCSRNIES NIES, Tokyo, Japan 2.8° x 2.8° 34 L / 0.01 hPa

CMAM Univ Toronto/York Univ/Environment Canada

3.75 ° x 3.75°

71L / 0.0006 hPa

E39C DLR Oberpfaffenhofen, Germany 3.75 ° x 3.75°

39L / 10 hPa

GEOS CCM NASA/GSFC, USA 2° x 2.5° 55 L / 0.01hPa

LMDZrepro IPSL, France 2.5° x 3.75° 50 L / 0.07 hPa

MAECHAM4CHEM

MPI Mainz, MPI Hamburg, Germany 3.75 ° x 3.75°

39 L / 0.01 hPa

MRI MRI, Tsukuba, Japan 2.8° x 2.8° 68 L / 0.01 hPa

SOCOL PMOD/WRC and ETHZ, Switzerland 3.75 ° x 3.75°

39 L / 0.1 hPa

ULAQ University of L'Aquila, Italy 10° x 22.5° 26 L / 0.04 hPa

UMETRAC UK Met Office, UK; NIWA Lauder, NZ 2.5° x 3.75° 64 L / 0.01 hPa

UMSLIMCAT University of Leeds, UK 2.5° x 3.75° 64 L / 0.01 hPa

WACCM NCAR, USA 4° x 5° 66 L / 10-6 hPa

CCM Participating Models

Tropopause

Stratopause

AOGCM Vertical Model Levels

Cordero and Forster, 2006

CC

M M

odel

s

AOGCM Temperature bias: Models with high lid compared to models with low lid

High lid models (> 45km)

Low lid models (< 45km)

NCEP 2σCordero and Forster, 2006

2020thth Century Temperature Time Series Century Temperature Time Series and Trendsand Trends

Annual Global Temperature Anomaly @ 50 hPa

Pre

ssu

re (

hP

a)

Global Temperature Trends (1958-99)

ºK/decade

AOGCM/CCM Global Temperature Trends (1958-99)

Yes O3

No O3

Sonde*

AOGCM/CCM Global Temperature Trends (1980-99)

SH Extratropics AOGCM/CCM Global TempTrends (1980-99)

2121stst Century Simulations Century Simulations AOGCMs A1/B2AOGCMs A1/B2

CCMs A1B CCMs A1B

Trends in temperatureTrends in temperature

Global Temperature @ 10hPa A2/A1B Scenario

Global Temperature @ 50hPa A2/A1B Scenario

Global Temp Trends (2000-2050) A2/A1B Scenario

SON - SH extratropics- Temp Trends A2/A1B Scenario

Global Average Temperature Trend 2000-2100

Pre

ssu

re (

hP

a)

ºK/decade

2000-2050 Temp Trends A2/B1 Scenario

Global Average Temperature Trend 2000-2100

Pre

ssu

re (

hP

a)

ºK/decade

2000-2050 Temp Trends A2/A1B/B1 Scenario

Global Average Temperature Trend 2000-2100

Pre

ssu

re (

hP

a)

ºK/decade

2000-2100 Temp Trends A2/A1B/B1 Scenario

SummarySummary 20th Century

– The AOGCM and CCMs produce similar temperature trends (for models including ozone forcing).

– Models trends without ozone forcing appear different in upper troposphere for some regions.

21st Century

– Stratospheric temperature strongly affected by emission scenario.

– CCM simulations of ozone recovery may not based on a middle range emission scenario.

Steps ForwardSteps Forward

Determine ozone forcing fields in AOGCM simulations (future scenarios).

CCM and AOGCM model simulations where interactive chemistry can be isolated.

Further investigate seasonal trends at different latitude ranges.

Aim of the Study:

– PART 1: Evaluation of the current generation of coupled chemistry-climate models (CCMs)

– PART 2: Long-term decadal projections of stratospheric ozone in the 21st century

Motivation:

– WMO/UNEP Assessment 2007, in particular Chapter 6: The Ozone Layer in the 21st Century (Greg E. Bodeker, Darryn W. Waugh et al.)

– IPCC 2007, in particular Chapter 7: Couplings Between Changes in the Climate System and Biogeochemistry (Ken L. Denman, Guy Brasseur, et al.)

The goal of CCMVal is to improve understanding of CCMs through process-oriented evaluation, along with discussion and coordinated analysis of science results.

Annual Global Temperature @ 50 hPa

AOGCM Annual Global Temperature @ 50 hPa

Pre

ssu

re (

hP

a)

Global Average Temperature Trend 2000-2050

Pre

ssu

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hP

a)

Global Average Temperature Trend 2000-2050 (Fixed ozone)