“Comparisons Between Observed And Modeled Precipitation And Temperature

Extremes In South America During The XX Century (Ipcc 20c3m).

Part I: Mean, Variability and MSE”.

Matilde Rusticucci (UBA),

José Marengo (CPTEC), Olga Penalba (UBA), Madeleine Renom (UR)

Extreme indices used

Extreme indices were derived from IPCC models (IPCC web site) and from observations in South America [based on Frich et al. 2002, Vincent et al. 2005, Haylock et al. 2005)]

• Objective: • how IPCC global models simulate climate

extreme indices over South America.

• we compare simulated indices with station data

indices, for 1961-2000

– Mean– Standard Deviation and – Mean Square Error:

• diff between the nearest station to the grid point.

Frost Days (FD) Mean

MIROC3.2 hiresCCSM3

0115

30

60

90

12

0

15

0

21

0

27

0

30

0

33

0

GFDL 2.0 GFDL 2.1

03.9

7.8

11.

7

15.

5

Frost Days (FD) StD GFDL 2.0 GFDL 2.1

CCSM3 MIROC3.2 hires

1510152025303540455055

MIROC3.2hires

GFDL 2.1 GFDL 2.0

CCSM3

Frost Days (FD) MSE

Warm Nights (Tn 90) MeanGFDL 2.1 GFDL 2.0

MIROC3.2 hiresCCSM3

4.5

7.5

10.5

13.5

16.5

Warm Nights (TN90) StD.

GFDL 2.0

MIROC3.2 hiresCCSM3

GFDL 2.1

26101418

Warm nights (Tn90) MSEGFDL 2.1 GFDL 2.0

MIROC3.2 hiresCCSM3

0

2

4

6

8

GFDL 2.1 GFDL 2.0

MIROC3.2 hiresCCSM3

0306090120

150

180

210

240

270

300

330

Consecutive Dry Days (CDD) Mean

GFDL 2.1 GFDL 2.0

MIROC3.2 hiresCCSM3

215284053

Consecutive Dry Days (CDD) StD

GFDL 2.1 GFDL 2.0

MIROC3.2 hiresCCSM3

051 01 52 02 53 03 54 04 55 05 5

Consecutive Dry Days (CDD) MSE

GFDL 2.1 GFDL 2.0

MIROC3.2 hires

CCSM3

050

10

0

15

0

20

0

25

0

30

0

Max. 5 Days precipitation (R5d) Mean

GFDL 2.1 GFDL 2.0

MIROC3.2 hires

CCSM3

Max. 5 Days precipitation (R5d) Std.D

018.1

36.1

54.2

72.3

Max. 5Days Precipitation (R5d) MSE

GFDL 2.0 GFDL 2.1

CCSM3 MIROC3.2hires

051 01 52 02 53 03 54 04 55 05 5

Heavy Precipitation Days (R10) Mean

030

60

90

120

150

180

210

240

270

300

330

GFDL 2.0 GFDL 2.1

CCSM3 MIROC3.2hires

GFDL 2.0 GFDL 2.1

CCSM3 MIROC3.2hires

Heavy Precipitation Days (R10) StdD

0.0

3.8

7.5

11.3

15.0

GFDL 2.0 GFDL 2.1

CCSM3 MIROC3.2hires

Heavy Precipitation Days (R10) MSE

0.02.34.56.89.011.313.515.818.020.322.524.827.0

Summary• GFDL better reproduces Fd mean and interanual

variability.• Tn90 is the best modeled extreme.• CDD interannual variability is better represented

by MIROC but mean by CCSM3• R10 is well modeled.• Days over threshold (R10) are better

represented than precip amount (R5d)• Southeastern South America Temperature

extremes are best modeled by GFDL and precip by CCSM3 and MIROC.