Modeling North Pacific Decadal
Variations and
Their Teleconnection Patterns
2010/ 11/ 16
Speaker/ Pei-Ning Kirsten Feng
Advisor/ Yu-Heng Tseng
Outline
•
•
•
•
•
•
Literature Review
Motivation
Objective
Data and Model
Preliminary work
Summary
Teleconnections
-- 500 hPa Height
-- Sea Level Pressure
-- Sea Surface Temperature
Structure
500 hPa – EOF1
500 hPa – EOF2
• PNA
• WP
High Level – Low Level Interaction
SLP – EOF1
SLP – EOF2
• North Hemisphere -- AO
• Pacific -- ENSO/ PDO (SSHa EOF1)
• Pacific -- NPO
• Atlantic – NAO
Surface Interaction
SST – EOF1
• Pacific -- ENSO/ PDO (SSHa EOF1)
SST – EOF2
• Pacific – Victoria Mode(NPGO,
SSHa EOF2)
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.
1950~2009 PNA Index
4
2
0
-2
-4
1950
1960
1970
1980
1990
2000
2010
[NOAA CPC http://www.cpc.ncep.noaa.gov]
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.
1950~2009 AO Index
4
2
0
-2
[NOAA CPC http://www.cpc.ncep.noaa.gov]
-4
1950
1960
1970
1980
1990
2000
2010
Pacific SLP EOF1 – AL
Aleutian Low (AL)
•
[Di Lorenzo et al., 2008]
The first co-variability mode captures the
mature phase of ENSO and its atmospheric
teleconnections to the AL.
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
1950~2009 NAO Index
4
2
0
-2
-4
1950
[NOAA CPC http://www.cpc.ncep.noaa.gov]
1960
1970
1980
1990
2000
2010
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.
http://www.aoml.noaa.gov/phod/amo_faq.php
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).
1950~2009 PDO Index
3
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).
2
1
0
-1
-2
1950
1960
1970
1980
1990
2000
2010
[Mantua et al., 1997]
Pacific SST EOF1 – PDO/ENSO
Pacific Decadal Oscillation / El Nino-Southern Oscillation (PDO/ENSO)
•
The first leading mode is wellknown 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]
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]
Why Second Mode
• The NPGO leads decadal variations in the
strength of the Kuroshio-Oyashio connecting
California and Japan.
Di Lorenzo et al., 2008
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.
1950~2009 WP Index
3
2
1
0
-1
-2
-3
1950
1960
1970
1980
1990
2000
2010
[Barnston and Livezey, 1987]
Pacific SLP EOF2 – NPO
North Pacific Oscillation (NPO)
•
[Di Lorenzo et al., 2008]
NPO, the second mode of North Pacific SLPa,
dominantly forces the North Pacific Gyre
Oscillation (NPGO).
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]
Motivation / Objective
-- Motivation
-- Objective
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?
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.
Methods and Model
- Data Source
- Model
- Methods
Data source
• Hadley SST
– 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
Preliminary Work
- Ongoing Work
- Future Work
500 hPa Height EOF1 -- PNA
Pacific / North American Pattern (PNA)
500hPa Height EOF 1 (30.1177%)
4
84oN
3
2
o
72 N
1
0
60oN
-1
500hPa Height PC1 & PNA index
o
48 N
3
Corrcoef = 0.501
500hPa Height PC1 & PNA index (R=0.501)
2
-3
125oE
1
0
-1
-2
-3
-2
500hPa Height PC1(positive)
500hPa Height PC1 (negative)
PNA Index
36oN
1960
1970
1980
1990
2000
150oE
175oE
160oW
135oW
-4
500 hPa Height EOF2 -- WP
Western Pacific Pattern (WP)
500hPa Height EOF 3 (11.5935%)
4
84oN
• The western pacific pattern
(WP) is the SLP EOF2 pattern
during DJFM in the region of
20~85N, 120E~120W.
3
2
o
72 N
1
0
60oN
-1
48oN
1950~2009 500hPa Height PC3 & WP Index
-2
3
500hPa Height PC3 (positive)
500hPa Height PC3 (negative)
o
WP Index
Corrcoef = 0.528
500hPa Height PC3 & WP index (R=0.528)
2
36 N
-3
125oE
1
150oE
175oE
160oW
135oW
-4
0
-1
-2
-3
1960
1970
1980
1990
2000
[Barnston and Livezey, 1987]
NH SLP EOF1 -- AO
Arctic Oscillation (AO)
SLP EOF 1 (46.9407%)
5
18 o
0
W
oW
0
12
36 o
N
4
48 o
N
3
60 o
N
60oW
120oE
72 o
N
84 o
N
1950~2009 AO Index
2
1
4
0
2
-1
0
0o
-2
-4
1950
1960
1970
1980
1990
2000
2010
oE
60
-2
Pacific SLP EOF1 -- AL
Aleutian Low (AL)
SLP 1 (28.1137%)
60
40
20
0
-20
1900-2009 Combined EOF PC1
Combined EOF PC1 (positive)
Combined EOF PC1 (negative)
Nino 3.4 Index
4
Corrcoef = 0.898
Combined EOF PC1 & Nino 3.4 index (R=0.898)
3
2
-260
-1.5
1
0
-1
-2
-3
-40
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
-240
-1
-220
-200
-0.5
-180
-160
0
-140
-120
0.5
-100
1
-80
-60
1.5
Pacific SLP EOF2 -- NPO
North Pacific Oscillation (NPO)
SLP 2 (6.6139%)
60
40
20
0
1900-2009 Combined EOF PC2
4
Combined EOF PC2 (positive)-20
Combined EOF PC2 (negative)
NPGO Index
Combined EOF PC2 & NPGO Index (R=0.486)
3
Corrcoef = 0.486
-40
2
-260
-240
-220
-200
-180
-160
-140
-120
-100
-80
-60
1
-1.5
0
-1
-2
-3
-4
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
-1
-0.5
0
0.5
1
1.5
Atlantic SLP EOF1 -- NAO
North Atlantic Oscillation (NAO)
SLP EOF 1 (51.0839%)
o
90 N
75oN
60oN
1900-2009 North Atlantic SLP EOF PC1
3
SLP PC1 (positive)
SLP PC1 (negative)
NAO Index
o
SLP PC 1 & NAO index (R=0.670)
2
Corrcoef = 0.670
45 N
30oN
1
75oW
0
50oW
25oW
0o
25oE
-1
-2
-2
-3
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
-1
0
1
2
3
4
Atlantic Long-term SSTa -- AMO
Atlantic Multidecadal Oscillation (NPO)
1900-2009 AMO Time Series
1
0.8
Corrcoef = 0.442
SSTa in AMO Region & AMO Index (R=0.442)
0.6
0.4
STD
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
1900
1925
1950
Time
1975
2000
Pacific SST EOF1 – PDO/ENSO
Pacific Decadal Oscillation / El Nino-Southern Oscillation (PDO/ENSO)
SLP 1 (28.1137%)
60
40
20
0
1900-2009 Combined EOF PC1
4
-20
Combined EOF PC1 (positive)
Combined EOF PC1 (negative)
Nino 3.4 Index
Corrcoef = 0.898
Combined EOF PC1 & Nino 3.4 index (R=0.898)
-40
3
-260
-240
-220
-200
-180
-160
-140
-120
-100
-80
-60
2
-1.5
1
0
-1
-2
-3
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
-1
-0.5
0
0.5
1
1.5
Pacific SST EOF2 – Victoria Mode
SSH EOF2 -- North Pacific Gyre Oscillation (NPGO)
SST 2 (6.6139%)
60
40
20
0
1900-2009 Combined EOF PC2
-20
4
Combined EOF PC2 (positive)
Combined EOF PC2 (negative)
NPGO Index
Combined EOF PC2 & NPGO Index (R=0.486)
3
Corrcoef = 0.486
-40
-260
2
-240
-220
-200
-180
-160
-140
-120
-100
-80
1
-0.5
0
-1
-2
-3
-4
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
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.
Model
( ECHAM5 / SIT / DIECAST )
Year: 1871 to 2008
19 levels
T31
DIECAST (OGCM)
31 Levels (2 deg)
SIT (Air/Snow/Ice/Thermocline)
2snow+2ice+41 water levels
ECHAM (AGCM)
ECHAM5 –
AGCM, running at various
resolutions.
SIT –
a one-column
snow/ice/ocean model
with 41-level ocean+ 2level ice + 2-level snow.
DIECAST –
OGCM with 2 degree in
the equator, covering
from 60°S to 60°N, with
31 levels.
Summary
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.
Atmosphere-Ocean Interaction
PNA / AO / NAO ?
WP ?
[Di Lorenzo et al., 2010]
Thank You
～To Be Continued～