1. 2010/ 11/ 16 Speaker/ Pei-Ning Kirsten Feng Advisor/ Yu-Heng Tseng
Modeling North Pacific Decadal Variations and Their Teleconnection Patterns
2010/ 11/ 16
Speaker/ Pei-Ning Kirsten Feng
Advisor/ Yu-Heng Tseng

2. Outline Literature Review Motivation Objective Data and Model
Preliminary work
Summary

3. -- 500 hPa Height -- Sea Level Pressure -- Sea Surface Temperature
Teleconnections
hPa Height
-- Sea Level Pressure
-- Sea Surface Temperature

4. High Level – Low Level Interaction
Structure
500 hPa – EOF1
PNA
SLP – EOF1
North Hemisphere -- AO
Pacific -- ENSO/ PDO (SSHa EOF1)
Atlantic – NAO
SST – EOF1
500 hPa – EOF2 WP
SLP – EOF2
Pacific -- NPO
SST – EOF2
Pacific – Victoria Mode(NPGO, SSHa EOF2)
High Level – Low Level Interaction
Surface Interaction

5. 500 hPa Height EOF1 -- PNA Pacific / North American Pattern (PNA)
The Pacific/ North American teleconnection pattern (PNA) is one of the most prominent modes of low-frequency variability in the Northern Hemisphere extratropics.
[NOAA CPC

6. NH 1000 hPa Height EOF1 -- AO Arctic Oscillation (AO)
The loading pattern of the AO is defined as the leading mode of Empirical Orthogonal Function (EOF) analysis of monthly mean 1000mb height.
[NOAA CPC

7. Pacific SLP EOF1 – AL Aleutian Low (AL)
The first co-variability mode captures the mature phase of ENSO and its atmospheric teleconnections to the AL.
[Di Lorenzo et al., 2008]

8. Atlantic SLP EOF1 -- NAO North Atlantic Oscillation (NAO)
One of the most prominent teleconnection patterns in all seasons is the North Atlantic Oscillation (NAO). It combines parts of the East-Atlantic and West Atlantic patterns with a north-south dipole of anomalies
[NOAA CPC

9. Atlantic Long-term SSTa -- AMO
Atlantic Multidecadal Oscillation (NPO)
The Atlantic Multi-decadal Oscillation (AMO) is a mode of natural variability occurring in the North Atlantic Ocean and which has its principle expression in the sea surface temperature (SST) field.

10. Pacific SST EOF1 – PDO/ENSO
Pacific Decadal Oscillation / El Nino-Southern Oscillation (PDO/ENSO)
Warm Phase Cool Phase
The PDO is highly correlated with the dominant mode of sea surface height anomalies (SSHa).
The Pacific Decadal Oscillation (PDO) Index is defined as the leading principal component of North Pacific monthly sea surface temperature (SST) variability (poleward of 20N).
[Mantua et al., 1997]

11. Pacific SST EOF1 – PDO/ENSO
Pacific Decadal Oscillation / El Nino-Southern Oscillation (PDO/ENSO)
The first leading mode is well-known as the ENSO pattern. And the mid-high latitude is shown as the PDO pattern (red rectangle).
This is now thought that those mid-latitude variation may be the footprint of tropical forcing .
[Di Lorenzo et al., 2008]

12. Why Second Mode PDO index can’t explain those variations in the ocean.
NPGO is the dominant mode of the salinity and the nutrients.
[Wright et al., 2009]

13. Why Second Mode
The NPGO leads decadal variations in the strength of the Kuroshio-Oyashio connecting California and Japan.
Di Lorenzo et al., 2008

14. 500 hPa Height EOF2 -- WP Western Pacific Pattern (WP)
The western pacific pattern (WP) is the SLP EOF2 pattern during DJFM in the region of 20～85N, 120E～120W.
[Barnston and Livezey, 1987]

15. Pacific SLP EOF2 – NPO North Pacific Oscillation (NPO)
NPO, the second mode of North Pacific SLPa, dominantly forces the North Pacific Gyre Oscillation (NPGO).
[Di Lorenzo et al., 2008]

16. Pacific SST EOF2 – Victoria Mode
SSH EOF2 -- North Pacific Gyre Oscillation (NPGO)
In the midlatitude and the North Pacific, the spatial pattern of the SSTa SEOF2 is nearly identical to the SSTa expression of the NPGO and of the second EOF of North Pacific SSTa, which has been referred to as the Victoria Mode [Bond et al., 2003].
[Di Lorenzo et al., 2008]

17. Motivation / Objective

18. Motivation
Decadal and low-frequency climate variabilities in the Pacific and other basins are not well understood.   What are the underlying physical mechanisms for these low-frequency climate variability?  
Can the latest AOGCM capture these climate patterns and variabilities for better future prediction?  
What is the role of atmospheric-ocean interaction? Are these climate variabilities related?

19. Objective
To summary and clarify the low frequency variability in the North Pacific Ocean and their links with the global patterns.  
To assess and evaluate the coupled climate model capability in capturing the patterns of variability in the North Pacific.  
To understand and verify the underlying physical mechanisms in North Pacific climate variability.  
To bridge the regional climate variability in the North Pacific with a complete picture of global climate change throughout the Pacific basin.

20. Data Source Model Methods
Methods and Model
Data Source
Model
Methods

21. Data source Hadley SST Hadley SLP NCEP/NCAR Reanalysis 1
1º x 1º HadISST1 from 1900 to 2009.
Hadley SLP
5º x 5º HadSLP2 from 1900 to 2009
NCEP/NCAR Reanalysis 1
2.5º x 2.5º Reanalysis 500 Height from 1950 to 2009

22. Ongoing Work Future Work
Preliminary Work
Ongoing Work
Future Work

23. 500 hPa Height EOF1 -- PNA Pacific / North American Pattern (PNA)
Corrcoef = 0.501

24. 500 hPa Height EOF2 -- WP Western Pacific Pattern (WP)
The western pacific pattern (WP) is the SLP EOF2 pattern during DJFM in the region of 20~85N, 120E~120W.
Corrcoef = 0.528
[Barnston and Livezey, 1987]

25. NH SLP EOF1 -- AO
Arctic Oscillation (AO)

26. Pacific SLP EOF1 -- AL
Aleutian Low (AL)
Corrcoef = 0.898

27. Pacific SLP EOF2 -- NPO North Pacific Oscillation (NPO)
Corrcoef = 0.486

28. Atlantic SLP EOF1 -- NAO North Atlantic Oscillation (NAO)
Corrcoef = 0.670

29. Atlantic Long-term SSTa -- AMO
Atlantic Multidecadal Oscillation (NPO)
Corrcoef = 0.442

30. Pacific SST EOF1 – PDO/ENSO
Pacific Decadal Oscillation / El Nino-Southern Oscillation (PDO/ENSO)
Corrcoef = 0.898

31. Pacific SST EOF2 – Victoria Mode
SSH EOF2 -- North Pacific Gyre Oscillation (NPGO)
Corrcoef = 0.486

32. Future Work
To assess and evaluate the coupled climate model capability in capturing the patterns of variability in the North Pacific.
compare the atmospheric and the teleconnection patterns between these models and observations.
evaluate the characteristics of modeled ENSO and the two associated types in the coupled runs.
To understand and verify the underlying physical mechanisms in North Pacific climate variability.
Verify the framework of the North Pacific Climate Variability
To bridge the regional climate variability in the North Pacific with a complete picture of global climate change throughout the Pacific basin.

33. Model ( ECHAM5 / SIT / DIECAST )
Year: 1871 to 2008
ECHAM5 –
AGCM, running at various resolutions.
SIT –
a one-column
snow/ice/ocean model with 41-level ocean+ 2-level ice + 2-level snow.
DIECAST –
OGCM with 2 degree in the equator, covering from 60°S to 60°N, with 31 levels.
ECHAM (AGCM)
19 levels
T31
SIT (Air/Snow/Ice/Thermocline)
2snow+2ice+41 water levels
DIECAST (OGCM)
31 Levels (2 deg)

34. Summary

35. Summary
The leading EOF patterns in the 500hPa, SLPa, and SSTa in the North Pacific are all related to the Aleutian Low. And the ENSO pattern may impact the mid-high latitude variations by atmosphere.
The second mode in the Pacific now becomes more important because its time series is highly related to the changes of ocean variables.
The further we want to realize is about what role other teleconnections play in the north hemisphere.

36. Atmosphere-Ocean Interaction
PNA / AO / NAO ?
WP ?
[Di Lorenzo et al., 2010]

37. Thank You
～To Be Continued～