M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
Climate Variability and the 3D Structure of Coastal Upwelling
Michael JacoxOctober 23, 2014
Collaborators: Andy Moore, Chris Edwards, Jerome Fiechter
M. Jacox | Decadal Scale Upwelling Variability in the California Current System | July 14, 2014
How Do We Study Upwelling?
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
1800 km !!
Model Configuration (1988-2010)
oceanmodeling.ucsc.edu
Regional Ocean Modeling System (ROMS) 4DVAR Data Assimilation (SST, SSH, In situ)
1/10° horizontal resolution 42 vertical levels ECMWF fluxes
CCMP wind San Francisco Bay
Cape Mendocino
Cape Blanco
Pt. Conception
Monterey Bay
2000 km
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
An Overview of CCS Upwelling
Vertical velocity is calculated at 40m depth !Long-‐term mean upwelling extends approximately 200 km offshore
Three distinct regions (Dorman and Winant, 1995): !North Storm track, variable forcing !Central Persistent equatorward winds !South Sheltered from strong winds
Cape Blanco
Cape Mendocino
Monterey Bay
Pt. Conception
Mean Vertical Velocity (m/day)
San Francisco Bay
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
An Overview of CCS Upwelling
Cape Blanco
Cape Mendocino
Monterey Bay
Pt. Conception
Mean Vertical Velocity (m/day)
Upwelling (m2/s)
Mean Upwelling Transport
Cape Blanco
Cape Mendocino
Monterey Bay
Pt. Conception
San Francisco Bay
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
Discrepancies in Upwelling Estimates
1. Upwelling Index overestimates Ekman Transport !Discrepancy between model wind and upwelling index wind (data issue)
2. Ekman Transport overestimates upwelling !Discrepancy between wind-‐driven transport and vertical transport (dynamical issue) !Caused by cross-‐shore geostrophic flow (Marchesiello and Estrade, 2010)
Upwelling (m2/s)
1
2
Mean Upwelling Transport
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
Capturing Interannual Variability in 2D
Cape Mendocino
Monterey Bay
Cape Blanco
Point Conception
Cape Mendocino
Monterey Bay
Cape Blanco
Point Conception
2008 2010
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
Capturing Interannual Variability in 2D
Year
Cape Blanco
Monterey Bay
35% Explained Variance
42% Explained Variance
PC Amplitu
dePC
Amplitu
de
EOF1
EOF1
San Francisco Bay
Cape Mendocino
Point Conception
Jacox et al. (2014)
47
46
45
44
43
42
41
40
39
38
37
36
35
-‐126 -‐124 -‐122
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
Capturing Interannual Variability in 2D
Cape Mendocino
Monterey Bay
Year
42% Explained Variance
Cape Blanco
PC Amplitu
dePC
Amplitu
de
11% Explained Variance
EOF2
EOF1
San Francisco Bay
Jacox et al. (2014)
Point Conception
47
46
45
44
43
42
41
40
39
38
37
36
35
-‐126 -‐124 -‐122
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
The Central CCS Response to PDO/NPGO
Year
r = 0.62 r = 0.61
Jacox et al. (2014)
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
The Central CCS Response to PDO/NPGO
Year
r = 0.62 r = 0.61
PDO+ NPGO-‐
PDO-‐ NPGO+
Jacox et al. (2014)
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
The Central/Northern CCS Response to PDO/NPGO
Cape Blanco
Cape Mendocino
Monterey Bay
Cape Blanco
Cape Mendocino
Monterey Bay
PDO+/NPGO-‐ (1993-‐1996) PDO-‐/NPGO+ (2007-‐2010)
Vertical Velocity
Ano
maly (m
/day)
Vertical Velocity
Ano
maly (m
/day)
San Francisco Bay
San Francisco Bay
Jacox et al. (2014)
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
The Central/Northern CCS Response to PDO/NPGO
Cape Blanco
Cape Mendocino
Monterey Bay
Cape Blanco
Cape Mendocino
Monterey Bay
PDO+/NPGO-‐ (1993-‐1996) PDO-‐/NPGO+ (2007-‐2010)
Vertical Velocity
Ano
maly (m
/day)
Vertical Velocity
Ano
maly (m
/day)
+25%-‐71%
+23%
-‐24%
-‐17%+25%
-‐45%
+34%San Francisco
BaySan Francisco
Bay
Jacox et al. (2014)
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
Upwelling Response to Coastal Wind Profiles
Jacox and Edwards (2012)
1988-‐2010
Distance From Coast (km)
Depth (m
)
Distance From Coast (km)
Depth (m
)
PDO+ NPGO-‐
PDO-‐ NPGO+
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
A Hypothesis on Biological Implications
1993-‐1996 (PDO+, NPGO-‐)
2007-‐2010 (PDO-‐, NPGO+)
Small Phytoplankton
Chl (m
g/m
2 )Large Ph
ytop
lankton Ch
l (mg/m
2 )
NEMURO biogeochemical model coupled to ROMS: !!Two phytoplankton: Small (nanophytoplankton) Large (diatoms)
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
A Hypothesis on Biological Implications
1993-‐1996 (PDO+, NPGO-‐)
2007-‐2010 (PDO-‐, NPGO+)
Small Phytoplankton
Chl (m
g/m
2 )Large Ph
ytop
lankton Ch
l (mg/m
2 )
NEMURO biogeochemical model coupled to ROMS: !!Two phytoplankton: Small (nanophytoplankton) Large (diatoms)
Hypothesis: Intense nearshore upwelling (PDO-‐, NPGO+) favors large phytoplankton !Widespread weak upwelling (PDO+, NPGO-‐) favors small phytoplankton. !(Rykaczewski and Checkley, 2008)
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
A Hypothesis on Biological Implications
1993-‐1996 (PDO+, NPGO-‐)
2007-‐2010 (PDO-‐, NPGO+) Difference
Small Phytoplankton
Chl (m
g/m
2 )Large Ph
ytop
lankton Ch
l (mg/m
2 )
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
A Hypothesis on Biological Implications
-PDO
Small phytoplankton chlLarge phytoplankton chl
r = 0.62
r = -0.72r = 0.80
Upwelling PC1
Upwelling PC1
1990 1995 2000 2005 2010
1990 1995 2000 2005 2010
M. Jacox | Climate Variability and the 3D Structure of Coastal Upwelling | October 23, 2014
Sardines and Anchovies: A Physical Mechanism?
Chavez et al. (2003)
Rykaczewski and Checkley (2008)
PDO+ !Widespread weak upwelling !Sardines
PDO+ = Sardines, PDO-‐ = Anchovies
Weak upwelling = Sardines, Strong upwelling = Anchovies
PDO-‐ !Intense coastal upwelling !Anchovies
