Lessons learned in C20C “Pacemaker” experiments James L. Kinter Ⅲ and K. Emilia Jin Center for Ocean-Land-Atmosphere Studies, USA James L. Kinter Ⅲ and

Lessons learned in C20C Lessons learned in C20C “Pacemaker” experiments“Pacemaker” experimentsLessons learned in C20C Lessons learned in C20C

“Pacemaker” experiments“Pacemaker” experiments

James L. Kinter James L. Kinter ⅢⅢ andand K. Emilia Jin K. Emilia Jin

Center for Ocean-Land-Atmosphere Studies, USACenter for Ocean-Land-Atmosphere Studies, USA

James L. Kinter James L. Kinter ⅢⅢ andand K. Emilia Jin K. Emilia Jin

Center for Ocean-Land-Atmosphere Studies, USACenter for Ocean-Land-Atmosphere Studies, USA

Workshop on Climate of the 20th Century & Seasonal and Interannual Climate PredictionWorkshop on Climate of the 20th Century & Seasonal and Interannual Climate PredictionWorkshop on Climate of the 20th Century & Seasonal and Interannual Climate PredictionWorkshop on Climate of the 20th Century & Seasonal and Interannual Climate Prediction

C20C pace-maker experimentsC20C pace-maker experiments

Region for prescribed SST

Mixed-layer depth

Climate drift and relaxation

Blending zone with observed SST: tropics and polar region

Management of sea ice

Experimental IssuesExperimental Issues

Ongoing Pace-maker experiments in COLAOngoing Pace-maker experiments in COLA

ExperimentBlending

Mixed-layer depth Extratropics Tropics statustropics Polar

region

Run 014 points

(10-15N,10-5S) 70-60S,50-60N

30 times 9-grid smoothed Levitus climatology

Slab ocean mixed-layer

Observed interannual

SST5 yr

Run 029 points

(10-20N,10-20S)70-60S,50-

60N30 times 9-grid smoothed Levitus climatology



SST5 yr

Run 035 points

(10-20N,10-20S)70-60S,60-

70N

Zonal mean monthly Levitus climatology exc

ept Eastern Pacific


weak damping of 15W/m2/K


SST3 yr

Run 04 No blending 70-60S,60-70N

Zonal mean monthly Levitus climatology exc

ept Eastern Pacific




SST3 yr

Run 05 No blending70-60S,60-

70N

Zonal mean annual mean climatology

except Eastern Pacific




SST0.5 yr

Experiments

AGCM NCEP operational Global Forecast System (GFS)

T62 64 Levels

1. Prescribed region as pace-maker1. Prescribed region as pace-maker

Shaded region denotes that Shaded region denotes that dynamic term prevails over thermodynamic termdynamic term prevails over thermodynamic term

in 20-yr NCEP CFS (Climate Forecast System) simulationin 20-yr NCEP CFS (Climate Forecast System) simulation

The NCEP Climate Forecast System (CFS)

AGCM Resolution OGCM Resolution

NCEP operational Global Forecast System (GFS) T62 64 Levels MOM 3.0 1oX1/3 to 1o 40 Levels

ynamicsmodtherdynamicsdt

dSST

HC

Flux

p

sfc

t

SSTSST nn

2

11

1. Prescribed region as pace-maker1. Prescribed region as pace-maker

Years showing that Years showing that dynamic term prevails over thermodynamic termdynamic term prevails over thermodynamic term

in 20-yr NCEP CFS (Climate Forecast System) simulationin 20-yr NCEP CFS (Climate Forecast System) simulation

(a) Annual mean

(b) JJA (c) DJF

2. Mixed-layer depth in slab ocean model2. Mixed-layer depth in slab ocean model

Prescribed mixed-layer depth:Prescribed mixed-layer depth:

30 time 9-grid smoothed mixed layer depth 30 time 9-grid smoothed mixed layer depth of Levitus climatologyof Levitus climatology

Simulated minus observed SSTSimulated minus observed SST


Zonal mean mixed-layer depth for Levitus climatologyZonal mean mixed-layer depth for Levitus climatology

Each ocean basin Difference from Global mean

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan


Zonal mean mixed-layer depth for Levitus climatologyZonal mean mixed-layer depth for Levitus climatology

Each ocean basinEach ocean basin Difference from Global meanDifference from Global meanDifference from Global mean Difference from Global mean

except Eastern Pacificexcept Eastern Pacific

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Jan

Apr

Jul

Oct

Jan

Global mean except Eastern PacificGlobal mean

3. Climate drift and relaxation3. Climate drift and relaxation

Obs.with relaxation without relaxation

1949 1950 1951

1949 1950 1951

(a) Global mean SST except pace-maker region

(b) Simulated minus observed global mean SST difference

run 3 run 4

4. Blending zone with observed SST4. Blending zone with observed SST

5 points blending No blending

Ratio of observed SST

Cross section for 140W

Cross section for equator

1949 1950 1951

1949 1950 1951

4. Blending zone with observed SST4. Blending zone with observed SST



Obs.with blending without beldning

5. Sea ice / seasonality of mixed-layer depth5. Sea ice / seasonality of mixed-layer depth

Seasonal march of difference between simulated and observed SST over the North Pacific (100E-60W)

Seasonal march of mixed-layer depth

1949 1950 1951

1949 1950 1951

1949 1950 1951

1949 1950 1951


Seasonal march of sea Ice fraction over the Pacific (120E-120W)

Seasonal march of difference between simulated and observed SST over the North Pacific (100E-60W)

5. Sea ice5. Sea ice

Seasonal mean sea ice fraction climatology

for 1950-1999 Hadley Center data

1949 1950 1951

1949 1950 1951




Obseved global mean (0-360E, 60S-60N)Simulated global meanObserved North Pacific (100E-60W, 20-60N)Simulated North Pacific

Documents

Lessons learned in C20C “Pacemaker” experiments James L. Kinter Ⅲ and K. Emilia Jin Center for Ocean-Land-Atmosphere Studies, USA James L. Kinter Ⅲ and