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

North Pacific Gyre Oscillation (NPGO) California Current CalCOFI Observations North Asia (# America Line P $'& NPGO Salinity NPC NPGO "# KOE $'! Latitude N psu explains $ '# CalCOFI ! $'! !# ! $'& North Pacific ' $# NO 3 NPGO !"#$ !"%$ !""$ &$$$ NPGO SSHa pattern Sea Level Anomalies & ! mol m -3 ! !"# ! !!# ! !## ! $%# ! $&# ! $"# ! $!# ! $## $ Longitude W Gulf of Alaska ! & Line P Observations !'( ! ' Line P Salinity NPGO NPGO The NPGO index & ! Chl-a measures changes in the $'( std std North Pacific gyres $ $ circulation and explains ! $'( key physical-biological ! & NPGO Line P NO 3 ! ! ocean variables 1970 1980 1990 2000 & !"#$ !"%$ !""$ &$$$ & year std std $ $ Di Lorenzo et al., 2008 ! & & 1970 1980 1990 2000

PDO (EOF1 SSTa, SSHa) Aleutian Low (EOF1 SLPa) 60 60 !"# 60 40 40 40 20 20 20 SSTa pattern PDO Forcing 0 0 0 -200 -150 -100 -200 -150 -100 Chhak, Di Lorenzo et al., 2008 NPGO (EOF2 SSTa, SSHa) North Pacific Oscillation (EOF2 SLPa) 60 60 !$# (# "# 40 40 '# !# 20 20 $# SSHa pattern NPGO Forcing 0 0 ! !"# ! !!# ! !## ! $%# ! $&# ! $"# ! $!# ! $## -200 -150 -100 Walker and Bliss, 1932

The atmospheric forcing of the PDO and NPGO drive di � erent responses in coastal upwelling 1 2 Sea Level Pressure and Wind Vector Anomalies Upwelling depth index during PDO positive phase positive indicates shallow upwelling cell 60 & 60 !"# ! std $ 40 40 ! ! PDO Index Upwelling depth index ! & 20 20 !"#$ !"%$ !""$ &$$$ PDO Forcing pattern Chhak and Di Lorenzo, 2007 0 0 � 200 � 150 � 100 3 4 Sea Level Pressure and Wind Vector Anomaly Upwelling depth index G4-H,68./ during NPGO positive phase negative indicates shallow upwelling cell 60 !$# 60 & std 40 40 $ NPGO Index ! & Upwelling depth index 20 20 !"#$ !"%$ !""$ &$$$ NPGO Forcing pattern Chhak and Di Lorenzo, in prep. 0 0 -200 -150 -100

1 2 3 Northeast Pacific California Current Gulf of Alaska CalCOFI Observations Line P Observations Physical-Biological Variability PDO PDO & & explains PDO mode ! ! ° C Pacific Decadal Oscillation (PDO) $ $ $# EOF1 ! ! ! SSH CalCOFI SSTa Line P SSTa & ! & %# Line P $'& NPGO Line P Salinity Salinity NPGO !"#$ !"%$ !""$ &$$$ $'! &# psu $ CalCOFI ! $'! '# ! $'& NPGO Line P NO 3 ! !"# ! !$# ! !%# ! !&# ! !'# ! !(# ' NO 3 NPGO !"#$ !"%$ !""$ &$$$ & NPGO Mode explains & ! mol m -3 North Pacific Gyre Oscillation (NPGO) $ $ $# EOF2 ! & SSH Line P & !'( %# ! ' NPGO Chl-a 1970 1980 1990 2000 ! year std $'( &# $ Di Lorenzo et al., GRL 2008. CalCOFI ! $'( '# ! ! ! !"# ! !$# ! !%# ! !&# ! !'# ! !(# 1970 1980 1990 2000 !"#$ !"%$ !""$ &$$$

Strength of Kuroshio-Oyashio Extension Strength of North Pacific Current NPGO NPGO & KOE & NPC STD units $ $ ! & ! & R=0.5 R=0.9 1970 1980 1990 2000 1970 1980 1990 2000 year 1970 1980 1990 2000 North Asia (# America Line P NPC "# KOE Latitude N '# CalCOFI !# $# NPGO SSHa pattern ! !"# ! !!# ! !## ! $%# ! $&# ! $"# ! $!# ! $## Longitude W Correlation NPGO index with Satellite SSHa (1993-2007) Figure 1 ! #&' ! #&( ! #&$ # #&$ #&( #&'

$# 35.5 PC1 SSSa (C) (A) & %# latitude $ Line P psu ! & &# NPGO Index CalCOFI Line P SSSa !"#$ !"%$ !""$ &$$$ & Mean SSSa '# 32 $ $# (B) +0.15 ! & CalCOFI SSSa %# $'& latitude Line P !"#$ !"%$ !""$ &$$$ psu $'! &# $ CalCOFI ! $'! EOF1 SSSa '# ! $'& -0.15 1970 1980 1990 2000 ! !"# ! !$# ! !%# ! !&# ! !'# ! !(# longitude year 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, observed SSSa at Line-P, and observed SSSa from CalCOFI program.

$# 30 PC1 NO 3 (C) (A) & %# latitude $ Line P ! mol m -3 ! & &# NPGO Index Line P NO 3 !"#$ !"%$ !""$ &$$$ & Mean NO 3 CalCOFI '# 1.7 $ $# (B) +5.5 ! & CalCOFI NO 3 %# ' ! mol m -3 latitude Line P !"#$ !"%$ !""$ &$$$ & &# $ CalCOFI ! & EOF1 NO 3 '# -5.5 ! ' 1970 1980 1990 2000 ! !"# ! !$# ! !%# ! !&# ! !'# ! !(# longitude year Figure 3. Temporal and spatial variability of subsurface nitrate (NO 3 ). (A) Mean subusrface NO 3 from ROMS ocean model over the period 1950-2004. ( B ) First dominant mode of variability for model subsurface NO 3 anomaly inferred from EOF1. (C) Timeseries of NPGO index (black) compared to PC1 of NO 3 , observed NO 3 at Line-P, and observed NO 3 from CalCOFI program.

AL EXTRA-TROPICS Aleutian Low Trenberth and Hurrell, 1994 atmosphere PDO SSHa Rossby Waves Pacific Decadal Oscillation Mantua et al. 1997 KOE Meridional Mode ocean Miller et al., 2004 Axis of KOE Taguchi et al. 2007 ocean Decadal Variance of AL/PDO Pierce et al., 2000 Alexander et al., 2002 Vimont et al. 2005 ENSO ocean - atmosphere TROPICS

NPO/NPGO dynamics EXTRA-TROPICS ENSO dynamics NPO North Pacific Oscillation Walker and Bliss, 1932 atmosphere SSHa Rossby Waves NPGO North Pacific Gyre Oscillation KOE Zonal Mode Di Lorenzo et al. 2008 Ceballos et al. 2008 ocean Strength of KOE Taguchi et al. 2007 ocean SSTa footprinting Vimont et al. 2001 Precursor of NPO in WTP Di Lorenzo et al. in prep Linkin and Nigam, 2008 ENSO Schneider and ocean - atmosphere Di Lorenzo, in prep. TROPICS