Generation of Hyper Modes

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Generation of Hyper Modes
Multi-Decadal Climate Variability in
Observations, IPCC-Models and a Simple Zero Order
Ocean Model
Time scales
Spatial structure
by Dietmar Dommenget and Mojib Latif
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Outline

• Data/Models
• Signature of Multi-Decadal Variability
• Time Scales
• Spatial Structure
• Summary and Discussion

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Data

• Data/Models
• Signature
• Time Scales
• Spatial Structure

• HADISST 1870-2004 annual mean
• 10yrs running mean
• exp. detrended

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IPCC Models

• Data/Models
• Signature
• Time Scales
• Spatial Structure

10yrs running mean / linear detrended
Super ensemble time series 7x340 years
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OZ model

• Data/Models
• Signature
• Time Scales
• Spatial Structure

A simple Model of local Air Sea interaction

• Only vertical interaction
• (no lateral interaction)
• A Model of 96x48 vertical
• columns
• 19 z-levels 6m-500m
• Mixed Layer Dynamics
• Vertical diffusion decreasing
• with depth
• Coupled to ECHAM5
• 2000 years simulation

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Outline

• Data/Models
• Signature
• Time Scales
• Spatial Structure

• Signature of Multi-Decadal Variability

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Observed Leading Mode

• Data/Models
• Signature
• Time Scales
• Spatial Structure

(HADISST 1870-2004 annual mean / 10yrs running
mean / exp. detrended)
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Model Leading Mode

• Data/Models
• Signature
• Time Scales
• Spatial Structure

(pattern correlation 0.5)
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Spatial Structure in the OZ-Model

• Data/Models
• Signature
• Time Scales
• Spatial Structure

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Obs. SST spectra

• Data/Models
• Signature
• Time Scales
• Spatial Structure

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Model SST spectra

• Data/Models
• Signature
• Time Scales
• Spatial Structure

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Signatures of Multi-Decadal Variability

• Data/Models
• Signature
• Time Scales
• Spatial Structure

Time scales
Spatial structure
Spatial and time scale structure are similar in
Obs / IPCC-models / OZ-model gt Local Air-Sea
interaction may explain much of multi-decadal
variability
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Outline

• Data/Models
• Signature
• Time Scales
• Spatial Structure

OZ-Model

• Time Scales

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A Simple Model

• Data/Models
• Signature
• Time Scales
• Spatial Structure

vertical diffusion
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A Simple Model

• Data/Models
• Signature
• Time Scales
• Spatial Structure

vertical diffusion
OZ-Model
Simple Model
Observed
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Time Scales of the Simple Model

• Data/Models
• Signature
• Time Scales
• Spatial Structure

• gt Variance increase until 1,000 to 10,000 years

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Outline

• Data/Models
• Signature
• Time Scales
• Spatial Structure

• Spatial Structure

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OZ pattern vs time scale

• Data/Models
• Signature
• Time Scales
• Spatial Structure

annual
Multi decadal
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Atmospheric Teleconnections

• Data/Models
• Signature
• Time Scales
• Spatial Structure

500hPa (40yrs run-mean)
(basis 2000years)
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Tropical Extra-tropical Connection

• Data/Models
• Signature
• Time Scales
• Spatial Structure

(basis 2000years)
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Tropical Extra-tropical Connection

• Data/Models
• Signature
• Time Scales
• Spatial Structure

500hPa pattern
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Summary

• Simple model suggest time scales of up to
• 1,000 to 10,000 years

• A stationary Climate must have a flat spectrum at
  some finite time scale

Dommenget and Latif
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Discussion
Elements of Global Scale Hyper Modes
Dommenget and Latif
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Conclusions

• We need 10,000 years model simulation to
  understand feedbacks in the Ocean-Atmosphere
  interaction

• What is the role of ocean dynamics?

• The hyper modes project onto the global warming
  pattern
• gt global warming may excite global scale hyper
  modes.

Dommenget and Latif
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The End, Thank you!
Dommenget and Latif
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IPCC Model Errors