Climate Model and Predictionof Climate Change
Akira Noda
Meteorological Research Institute• Climate System of the Earth• Governing Equations• Projection of Global Warming– Mechanism of Global Warming– Experiments with the EarthSimulator

Climate Systemand ModelingGoverning Equations in
Climate System Modeling• Horizontal equations of motion• The hydrostatic equation• Thermodynamic equation• Continuity equation• Equation of state• Water vapor equation

Peculiarity of climatesystem modeling• Rotating EarthÎ Spherical coordinates,Coriolis force• Strong inhomogeneityÎ parameterization of subgrid-scale
phenomena(>> molecular viscosity, heat conduction)• Multi-scales in space and timeÎ Nesting method
Î Time-Slice method
Î Computer resources of CPUs and storage

The Earth’s climate system is a heattransport system.
summerwinter

QP,TPQE,TE

Dissipative
QE + QP = 0 Structure
dSe/dt=QE/TE+QP/TP < 0dS/dt=dSir/dt+dSe/dt = 0

Issue of Global WarmingMechanism of Greenhouse
Effect
N2,O2-18℃
N2,O2 + (H2O,CO2,CH4,N2O,CFC,O3)+15℃

CO2CH41860

2000

N2O

IPCC(2001)
1000

2000

IPCC SRES and Stabilization
ScenariosMRI-CGCM2.3

Typical Change patterns due to
Global Warming
Years 91 -110

Pressure (hPa)Years 91 -110

Years 91 -110

Latitude

MRI-CGCM1

Vertical Structure of the
Atmosphere and Global Warming
stratosphere

1xCO2

2xCO2

troposphere

Tropopause

Heating ＝ CoolingSolar（O3）
Infrared（CO2,O3）

Heating ＝ CoolingSolar （ H2O ） Infrared（H2O,CO2）
Convection/Diffusion

Temperature

Feedback Effect of Water Vapor
Emagramtemperature

stratosphere
tropopause
tropospherepressure

2xCO2

1xCO2

Snow/Seaice/Albedo Feedback
Effectand Deep Ocean Circulation

Global ocean circulation
pathways (conveyer belt)

丸山氏(電中研）提供

Typical Change patterns due toGlobal Warming
Years 91 -110

Pressure (hPa)Years 91 -110

Years 91 -110

Latitude

MRI-CGCM1

The Earth Simulator

Time-Slice Global Warming Experiment
Global Warming
Experiment with
CGCM

Time-SliceExperiment with
AGCM

Nesting TimeSlice Experimentwith RCM

300km-mesh
AGCM

20km-mesh AGCM

5km-mesh cloud
resolving RCM

AGCM

Predicted
AGCM
SST

SST

OGCM

Boundary
Condition

SST
Boundary
Condition
Present climate

warm climate

SST

200-50km
OGCM

１９７９−１９９８year

２０８０−２０９９

CGCM ∆SST = Future - Present

Future:2080-2099, 20 yrs Present:1979-1998, 20 yrs

Tropical Cyclones

Jan.,Feb., Mar.
Apr., May, Jun.
Jul., Aug., Sep.
Oct., Nov., Dec.

(Oouchi et al., 2005)

Change in Tropical Cyclones
Occurrence Frequency

Regions

Lat

Observation Present
Future20 years
10 years
10 years----------------------------------------------------------------------------------------------------------------------------Global
45S-45N ALL
83.7 (10.0)
78.3 (8.4) 54.8 (8.4) **N Hemisphere0 -45N ALL
58.0 ( 7.1)
42.9 (7.0) 30.8 (5.8) **S Hemisphere0 -45S ALL
25.7 ( 5.6)
35.4 (3.8) 24.0 (6.1) **N Indian Ocean
0 -45NWN Pacific Ocean 0 -45N
EN Pacific Ocean 0 -45N
N Atlantic Ocean 0 -45N

Lon

30E-100E 4.6 ( 2.4)
100E-180 26.7 ( 4.2)
180 - 90W 18.1 ( 4.8)
90W- 08.6 ( 3.6)

4.4 (2.5)
12.4 (3.7)
20.5 (3.4)
5.6 (2.7)

2.1 (1.7) **7.7 (2.6) **13.5 (5.7) *7.5 (1.8) #S Indian Ocean
0 -45S 20E-135E 15.4 ( 3.8)
25.8 (3.0) 18.6 (5.1) **S Pacific Ocean 0 -45S 135E- 90W 10.4 ( 4.0)
9.4 (3.3)
5.4 (1.9) **-----------------------------------------------------------------------------------------------------------------------------** Statistically significant decrease at 99 % confidence level.
* Statistically significant decrease at 95 % confidence level.
# Statistically significant increase at 95 % confidence level.

Oouchi et al., 2005

Change in Tropical Cyclones

number/year

Max wind speed distribution

Oouchi et al., 2005
normalizedSummary• The main function of the climate system of theearth is to transport heat from surface to upper
atmosphere, and tropics to polar regions.
• Global warming projection has been done by manymodels after evaluating their performance bysimulating 20 century climate change.
• Main response patterns in a warmer climate aredetermined by several basic climate processes.
• A time-slice experiment on the Earth Simulatorshows that the number of tropical cyclones
decreases globally (except for North Atlantic) but
intensity increases in a warmer climate.