Climate Baseline Scenarios and GCMs performance

By

Mario Bidegain (Facultad de Ciencias – UR LA32/LA26)

Ines Camilloni (Facultad de Ciencias – UBA LA26)

AIACC Latin America/Caribbean Regional Workshop

26-29 May 2003, San Jose, Costa Rica

1. What are GCMs?

2. What GCMs outputs were selected from IPCC

DDC? 3. What variables were selected for this study?

4. Preliminary conclusions for southeastern South America

OUTLINE

What are GCMs?What they do?Simulate the response of the global climate system to increasing

greenhouse gas concentrations.

Growth in population, energy demand, changes in technological and land/cover

Greenhouse gases emissions

Atmospheric GHGs concentrations

Baseline and future climate projections

Energy-economy models

Carbon cycle and other and other chemical models

Climate models

What are GCMs?

What they work?GCMs are based on the known laws of physics describing the transport of mass and energy, depicting the global climate using a three dimensional grid over the globe.

What GCM outputs were selected from IPCC DDC?

SRES A2 forced runs: CCCMA, CSIRO, GFDL, HadCM3, NCAR-PCM

MODEL PERIOD

HADCM3 1950-2000

CSIRO-Mk2 1961-2000

NCAR-PCM 1981-2000

CGCM2 1950-2000

ECHAM4 1990-2000

Region selected for this study

Southeastern Southamerica:

20° to 47° South 45° to 67° West

What variables were selected for this study?

Sea level pressure (as indicator of goodness of GCMsto reproduce the general circulation in the region)

Rainfall (mean monthly and annual values) and annual cycle)

Temperature (monthly mean and annual values)

Spatial Correlation for Sea Level Pressure between GCMs outputs and NCEP reanalysis

meses

corr

ela

ció

n e

spa

cia

l

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6 7 8 9 10 11 12

HADCM3CSIRP-Mk2CCCmaNCARECHAM4

- 7 5 - 7 0 - 6 5 - 6 0 - 5 5 - 5 0 - 4 5- 5 5

- 5 0

- 4 5

- 4 0

- 3 5

- 3 0

- 2 5

- 2 0

What climate baseline scenarios for SLP the GCMs estimate?

P R E S IO N M E D IA A N U A L A L N M MP E R IO D O 1 9 5 0 -2 0 0 0

M o d elo H A D L E Y

P R E S IO N A T M O S F E R IC A A L N M MP E R IO D O 1 9 5 0 -2 0 0 0

F u en te : R ea n a lis is N C E P /N C A R

P R E S IO N M E D IA A N U A L A L N M MP E R IO D O 1 9 5 0 -2 0 0 0

M o d elo C S IR O

Sea Level Pressure anomalies: GCMs vs.NCEP reanalysis

CSIRO-NCEP (1961-2000)

- 6 5 - 6 0 - 5 5 - 5 0 - 4 5

LON GITU D

- 4 5

- 4 0

- 3 5

- 3 0

- 2 5

- 2 0

LAT

ITU

D

- 6 5 - 6 0 - 5 5 - 5 0 - 4 5L ON GIT U D

- 4 5

- 4 0

- 3 5

- 3 0

- 2 5

- 2 0

LAT

ITU

D

HADCM3-NCEP (1950-2000)

- 6 5 - 6 0 - 5 5 - 5 0 - 4 5

L ON GIT U D

- 4 5

- 4 0

- 3 5

- 3 0

- 2 5

- 2 0

LAT

ITU

D

ECHAM4-NCEP (1990-2000) NCEP (1950-2000)

What climate baseline scenario for rainfall the GCMs estimate?

P R E C IP IT A C IO N (m m /d ia )C S IR O A N U A L (P E R IO D O 1 9 5 0 -2 0 0 )

P R E C IP IT A C IO N (m m /d ia )A N U A L P E R IO D O 1 95 0 - 2 0 0 0

N C E P /N C A R R E A N A L IS ISP R E C IP IT A C IO N (m m /d ia )H A D L E Y A N U A L (P E R IO D O 1 9 5 0 -2 0 0 0 )

-65 -60 -55 -50 -45

-45

-40

-35

-30

-25

-20

-15

-10

HADCM3 (1950-99)

GCMs rainfall anomalies (mm/day)

-65 -60 -55 -50 -45

-45

-40

-35

-30

-25

-20

-15

-10

CSIRO (1961-99)

-65 -60 -55 -50 -45

-45

-40

-35

-30

-25

-20

-15

-10

ECHAM4 (1991-99)

Rainfall annual cycle: GCMs vs. Climatology1990 - 2000

ANNUAL CYCLE OF PRECIPITATION(LAT:-20 LON:-56.25)

0

2

4

6

8

10

J AN MAR MAY J UL SEP NOV

mm

/day

Hadley

Csiro

Echam

Clima

ANNUAL CYCLE OF PRECIPITATION(LAT:-27.5 LON:-56.25)

0

2

4

6

8

10

J AN MAR MAY J UL SEP NOV

mm

/day

Hadley

Csiro

Echam

Clima

ANNUAL CYCLE OF PRECIPITATION(LAT:-35 LON:-56.25)

0

2

4

6

8

10

J AN MAR MAY J UL SEP NOV

mm

/day

Hadley

Csiro

Echam

Clima

ANNUAL CYCLE OF PRECIPITATION(LAT:-35 LON:-63.75)

0

2

4

6

8

10

J AN MAR MAY J UL SEP NOV

mm

/day

Hadley

Csiro

Echam

Clima

ANNUAL CYCLE OF PRECIPITATION(LAT:-27.5 LON:-63.75)

0

2

4

6

8

10

J AN MAR MAY J UL SEP NOV

mm

/day Hadley

Csiro

Echam

Clima

T E M P E R A T U R A M E D IA A N U A LP E R IO D O 1 9 5 0 -2 0 0 0

F u en te : R ea n a lis is N C E P /N C A RT E M P E R A T U R A (°C )

H A D L E Y A N U A L (P E R IO D O 1 9 5 0 -2 0 0 0 )

What climate baseline scenario for temperature the GCMs estimate?

T E M P E R A T U R A (°C )E C H A M A N U A L (P E R IO D O 1 9 9 0 -2 0 0 0 )

Global temperature change (2000-2100)

Precipitation and Temperature Changes Argentina 9 GCMs (2070-99 vs. 1961-90)

PRELIMINARY CONCLUSIONS

General Conclusion• Very good performance of GCMs in temperature and SLP, poor to

fair in rainfall (underestimation in the region), but improved performance respect to old GCMs versions

Future actions• 3 GCMs will be selected to construct climate scenarios

(HADLEY, ECHAM and CSIRO.• The selected variables will be: SLP (to estimate surface winds),

precipitation and temperature.• Statistical and/or dynamical downscalling, for selected locations,

will be applied to future climate scenarios.