Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon...
-
Upload
charlene-maxwell -
Category
Documents
-
view
214 -
download
0
Transcript of Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon...
![Page 1: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/1.jpg)
Equatorial Pacific primary productivity:Spatial and temporal variability and links to carbon cycling
Pete StruttonCollege of Oceanic and Atmospheric Sciences
Oregon State University
![Page 2: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/2.jpg)
Outline
• Physical processes that impact productivity– El Niño– Tropical instability waves (TIWs)– Kelvin waves (MJO)
• How might these processes change as climate changes?• What would be the resulting impact on carbon budgets?• What do the models say?• Variability at longer time-scales: PDO
![Page 3: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/3.jpg)
![Page 4: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/4.jpg)
![Page 5: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/5.jpg)
Physical and biological setting: 1997-2004
![Page 6: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/6.jpg)
![Page 7: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/7.jpg)
![Page 8: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/8.jpg)
Comparison of satellite and in situ data
The in situ database documents large-scale trends but misses ephemeral events
![Page 9: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/9.jpg)
Phytoplankton community composition
• Elevated nutrients in the upwelling zone relative to warm pool• Moderately high chlorophyll concentrations
– 0.2 to 0.3 mg m-3 cf 0.05 to 0.1 mg m-3 in the warm pool & gyres• Dominated by small planktonic species
– Prochlorococcus and Synechococcus– Competitive advantage in low nutrient environment because of large
surface area : volume– Survive on recycled N (as NH4) and Fe
• An additional diatom component, reliant on Fe and Si inputs• Export flux driven largely by the diatoms
![Page 10: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/10.jpg)
Variability of chlorophyll and nutrients: 1997-2004
![Page 11: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/11.jpg)
El Niño-La Niña mixed layer chlorophyll variability
![Page 12: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/12.jpg)
Species composition as a function of nutrients
Figure adapted from Dugdale et al., 2002
![Page 13: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/13.jpg)
El Niño-La Niña mixed layer nutrient variability
![Page 14: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/14.jpg)
El Niño-La Niña mixed layer nutrient variability
![Page 15: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/15.jpg)
El Niño-La Niña source nutrient variability
![Page 16: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/16.jpg)
El Niño-La Niña source nutrient variability
No change in source nutrients as a function of El Nino
Probably not true for iron (source is the EUC)
![Page 17: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/17.jpg)
Increased dominance of El Niño/La Niña?
Almost no change in source nutrients.
La Nina Normal Mild El Nino Strong El Nino
chl [mg m-3] 0.19 0.20 0.18 0.12
NO3 [uM] 4.97 4.10 2.82 0.91
SiO4 [uM] 3.60 3.16 2.65 1.68
PO4 [uM] 0.56 0.54 0.52 0.31
N:Si 1.34 1.25 1.02 0.38
![Page 18: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/18.jpg)
Impact of tropical instability waves (TIWs)
![Page 19: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/19.jpg)
SST and chlorophyll at 2°N 110°W: March to October 1998
20
22
24
26
28
30
32
Mar-98 Apr-98 May-98 Jun-98 Jul-98 Aug-98 Sep-98 Oct-98
SST [°C]
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Chlorophyll [
μ g l
-1]
SSTChl
Strutton et al., GRL, 2001.
![Page 20: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/20.jpg)
![Page 21: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/21.jpg)
0.4
0.5
0.6
0.7
0.8
0.9Growth
0.1
0.2
0.3
5 Day21 Day
4005006007008009001000110012001300
130
140
150
160
170
180
190 0.03
0.04
0.05
0.06
0.07
0.08
Depth
f
Date
12/1/96 1/1/97 2/1/97 3/1/97 4/1/97 5/1/973.0
3.5
4.0
4.5
5.0
25
26
27
28
29
NO3
SST (oC)
A
B
C
chl [
mg
m-3]
dept
h [m
]SS
T [°
C]
1 p
rod
[mgC
m-2 d
-1]
grow
th [d
-1]
f
NO3 [μM
]
![Page 22: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/22.jpg)
Impact of TIWs and Kelvin waves
• TIWs– Enhanced chlorophyll at the equator– Averaged over Wyrtki Box, essentially no difference– Evidence for enhanced diatom production and export– TIWs should become less dominant in an ‘El Niño climate’
• Kelvin waves– Small decrease in chlorophyll– Evidence for reduced diatom production and export– Enhanced or diminished in an ‘El Niño climate’?– Impact possibly diminished for a deeper thermocline
![Page 23: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/23.jpg)
Life in a more El Niño- or La Niña-like world
La Nina Mild El Nino Strong El Nino
chl no change no change -40%
NO3 +20% -30% -80%
SiO4 +15% -15% -50%
TIWs more fewer absent
Kelvin waves absent present ?
Export increase small decrease large decrease
Satellites can provide chl, but we need satellites + models to quantify changes in export
![Page 24: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/24.jpg)
• The system has been modeled as a chemostat - limiting nutrient(s) fed in via upwelling
• Can reproduce the general surface chlorophyll patterns well• Ability to reproduce processes and the subsurface structure
heavily dependent on the physics and available data• Controls on new production
– Depends on the type of physical forcing– Nutricline variability: El Nino and Kelvin waves– Variability in upwelling velocity: TIWs and short-term wind events
• Barely enough export data to know if they are getting it right
What do the models say?
![Page 25: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/25.jpg)
Global importance of equatorial Pacific productivity
Figure courtesy of Mike Behrenfeld, OSU
![Page 26: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/26.jpg)
Global importance of equatorial Pacific productivity
From Behrenfeld et al., Science, 2001.
Dec98-Feb99
Jun99-Aug99
98/99-97/98
1999-1998
![Page 27: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/27.jpg)
• El Niño to La Niña transition, 1997-2000• Increase in ocean NPP from ~50 to 53 PgC year -1
• Largely due to increases in:– Equatorial Pacific and Atlantic– Coastal upwelling regions (Canary, Arabian Sea)– Patagonian shelf and regions downstream
• Terrestrial productivity:– approximately constant, globally– regionally variable (Amazonia)
Global importance of equatorial Pacific productivity
![Page 28: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/28.jpg)
![Page 29: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/29.jpg)
The PDO’s impact on the equatorial Pacific
From Chavez et al., Science, 2003.
![Page 30: Equatorial Pacific primary productivity: Spatial and temporal variability and links to carbon cycling Pete Strutton College of Oceanic and Atmospheric.](https://reader038.fdocuments.in/reader038/viewer/2022110404/56649ebd5503460f94bc6631/html5/thumbnails/30.jpg)
• TAO array and satellites provide excellent synoptic view of broad physics and surface chlorophyll
• But, to predict the future we need better models• For this we need more data:
– Iron!– Phytoplankton community composition in response to nutrient fluxes– Spatial and temporal variability of export (TIWs)– Mixing and upwelling vs thermocline variability for fueling
productivity• Also need a better understanding of feedbacks
Productivity and export: Knowns and unknowns