NO 3 NPGO !"#$ !"%$ !""$ &$$$ NPGO SSHa - - PowerPoint PPT Presentation

!!"# !!!# !!## !$%# !$&# !$"# !$!# !$## $# !# '# "# (#

Line P

CalCOFI Asia

Latitude N Longitude W

KOE NPC

NPGO SSHa pattern

North America

North Pacific Sea Level Anomalies

North Pacific Gyre Oscillation (NPGO)

Di Lorenzo et al., 2008

California Current

CalCOFI Observations

!"#$ !"%$ !""$ &$$$ !! !$'( $ $'( ! !'( !"#$ !"%$ !""$ &$$$ !$'& !$'! $ $'! $'& !' !& $ & '

NO3 Chl-a NPGO Salinity NPGO NPGO

1970 1980 1990 2000

psu

!mol m-3

std

year

std

Gulf of Alaska

Line P Observations

1970 1980 1990 2000

& $ & Line P Salinity Line P NO3

NPGO NPGO

std !& $ & !& $ & std

NPGO explains The NPGO index measures changes in the North Pacific gyres circulation and explains key physical-biological

• cean variables

PDO (EOF1 SSTa, SSHa)

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NPGO (EOF2 SSTa, SSHa) Aleutian Low (EOF1 SLPa)

60 40 20

20 40 60

!"#

• 200
• 150

PDO Forcing

• 100

60 40 20

• 200
• 150
• 100

North Pacific Oscillation (EOF2 SLPa)

60 40 20

20 40 60

!$#

• 200
• 150
• 100

NPGO Forcing SSTa pattern SSHa pattern

Walker and Bliss, 1932

Chhak, Di Lorenzo et al., 2008

!"#$ !"%$ !""$ &$$$ !& !! $ ! & !"#$ !"%$ !""$ &$$$ !& $ &

20 40 60 200 150 100 20 40 60

!"# !$#

G4-H,68./

Sea Level Pressure and Wind Vector Anomalies during PDO positive phase Sea Level Pressure and Wind Vector Anomaly during NPGO positive phase

Upwelling depth index

positive indicates shallow upwelling cell

Upwelling depth index

negative indicates shallow upwelling cell

The atmospheric forcing of the PDO and NPGO drive dierent responses in coastal upwelling

Chhak and Di Lorenzo, 2007 Chhak and Di Lorenzo, in prep.

1 2

PDO Forcing pattern NPGO Forcing pattern

3 4

std std

60 40 20 60 40 20

• 200
• 150
• 100

PDO Index Upwelling depth index NPGO Index Upwelling depth index

!"#$ !"%$ !""$ &$$$ !! !$'( $ $'( ! !'( !"#$ !"%$ !""$ &$$$ !& !! $ ! &

!!"# !!$# !!%# !!&# !!'# !!(# '# &# %# $#

EOF2 SSH

!!"# !!$# !!%# !!&# !!'# !!(# '# &# %# $#

EOF1 SSH PDO mode

California Current CalCOFI Observations

PDO

!"#$ !"%$ !""$ &$$$ !$'& !$'! $ $'! $'& !' !& $ & '

NO3 Chl-a

std

NPGO Salinity

North Pacific Gyre Oscillation (NPGO) Pacific Decadal Oscillation (PDO)

NPGO NPGO

NPGO Mode

explains

CalCOFI SSTa

1970 1980 1990 2000

Northeast Pacific

Physical-Biological Variability

Line P

CalCOFI

Line P

CalCOFI

1970 1980 1990 2000

& $ & Line P Salinity Line P NO3

NPGO NPGO

& ! $ ! & Line P SSTa

Gulf of Alaska Line P Observations

psu

!mol m-3

°C

PDO

1 2 3

year

explains

Di Lorenzo et al., GRL 2008.

!& $ & !& $ & Strength of Kuroshio-Oyashio Extension Strength of North Pacific Current NPGO NPGO KOE NPC R=0.5 R=0.9

year STD units

!!"# !!!# !!## !$%# !$&# !$"# !$!# !$## $# !# '# "# (#

Line P

CalCOFI Asia

Latitude N

Correlation NPGO index with Satellite SSHa (1993-2007)

Longitude W

KOE NPC !#&' !#&( !#&$ # #&$ #&( #&'

NPGO SSHa pattern

North America

Figure 1

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000

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!"#$ !"%$ !""$ &$$$ !& $ & !"#$ !"%$ !""$ &$$$ !& $ & !$'& !$'! $ $'! $'&

EOF1 SSSa

(A) (B)

NPGO Index

Line P SSSa CalCOFI SSSa

(C)

1970 1980 1990 2000

PC1 SSSa

year

35.5 32 +0.15

• 0.15

longitude latitude latitude

Mean SSSa

Line P

CalCOFI

Line P

CalCOFI

psu psu

Figure 2. Temporal and spatial variability of surface salinity. (A) Mean surface salinity from ROMS ocean model over the period 1950-2004. (B) First dominant mode of variability for model surface salinity anomaly (SSSa) inferred from EOF1. (C) Timeseries of NPGO index (black) compared to PC1 of SSSa,

• bserved SSSa at Line-P, and observed SSSa from CalCOFI program.

!"#$ !"%$ !""$ &$$$ !& $ &

!!"# !!$# !!%# !!&# !!'# !!(# '# &# %# $# '# &# %# $#

EOF1 NO3 Mean NO3

(A) (B)

NPGO Index

!"#$ !"%$ !""$ &$$$ !& $ & Line P NO3 !' !& $ & ' CalCOFI NO3

(C)

1970 1980 1990 2000

PC1 NO3

year

30 1.7 +5.5

• 5.5

!mol m-3 !mol m-3

longitude latitude latitude

Line P

CalCOFI

Line P

CalCOFI

Figure 3. Temporal and spatial variability of subsurface nitrate (NO3). (A) Mean subusrface NO3 from ROMS ocean model over the period 1950-2004. (B) First dominant mode of variability for model subsurface NO3 anomaly inferred from EOF1. (C) Timeseries of NPGO index (black) compared to PC1 of NO3,

• bserved NO3 at Line-P, and observed NO3 from CalCOFI program.

AL PDO

EXTRA-TROPICS TROPICS

KOE Meridional Mode

SSHa Rossby Waves

ENSO

• cean - atmosphere

Pacific Decadal Oscillation Mantua et al. 1997

• cean

Axis of KOE

Taguchi et al. 2007

• cean

Miller et al., 2004 Pierce et al., 2000 Alexander et al., 2002 Vimont et al. 2005 Aleutian Low Trenberth and Hurrell, 1994

atmosphere

Decadal Variance of AL/PDO

EXTRA-TROPICS TROPICS

NPO

North Pacific Gyre Oscillation Di Lorenzo et al. 2008

• cean

North Pacific Oscillation Walker and Bliss, 1932

atmosphere

NPGO

SSHa Rossby Waves

KOE Zonal Mode

Strength of KOE

Taguchi et al. 2007

• cean

Ceballos et al. 2008

NPO/NPGO dynamics

• cean - atmosphere

ENSO

SSTa footprinting

Vimont et al. 2001 Di Lorenzo et al. in prep

Precursor of NPO in WTP

Linkin and Nigam, 2008 Schneider and Di Lorenzo, in prep.

ENSO dynamics