Up or down:

kayakjokeMécanique

22 févr. 2014 (il y a 3 années et 8 mois)

67 vue(s)

Institut

universitaire

europeen

de la
mer

(
iuem
)

Laboratoire

des sciences
l’environnement

marin

(LEMAR)

60

40

20

0

Up or down:

Modeling the fates and rates

of

phytoplankton carbon in

the North Atlantic Ocean


C
hristoph

Stegert

Laurent
Memery

Thomas
Gorgues

Julie
Deshayes

MOTIVATION: Where does the carbon go?


Background

MOTIVATION: Where does the carbon go?


Background

Background

P

DIC

MOTIVATION: Where does the carbon go?


Background

P

DIC

fisheries

MOTIVATION: Where does the carbon go?


Z

Fish

Food web

dynamics

Background

P

DIC

Z

Fish

D

Deep Sea

fisheries

Carbon export

MOTIVATION: Where does the carbon go?


Food web

dynamics

CO
2

storage

Background

P

DIC

D

Deep Sea

fisheries

Carbon export

Remineralisation

Sedimentation

MOTIVATION: Where does the carbon go?


CO
2

storage

Z

Fish

Food web

dynamics

Background

P

DIC

D

Deep Sea

fisheries

Carbon export

Remineralisation

Sedimentation

UP

or

DOWN

What
is/

What determines
this
ratio

MOTIVATION: Where does the carbon go?


CO
2

storage

Z

Fish

Food web

dynamics

Background

P

DIC

D

Deep Sea

CO
2

storage

fisheries

Carbon export

Remineralisation

Sedimentation

UP

or

DOWN

Possible
consequences
of
climate
change on the
ratio

What
is/

What determines
this
ratio

MOTIVATION: Where does the carbon go?


Z

Fish

Food web

dynamics

How much of Primary Production is transported to the deep
ocean (carbon export)?



What are regional differences in the carbon transport and
how do they change during the 1990
-
2010 period?



What is the structure of the links of primary production and
carbon export in the North Atlantic Ocean?

MOTIVATION: Where does the carbon go?


Specific questions I want to answer in this talk:

Besides carbon the nutrient (
N,P,Si,Fe
) and Oxygen cycles are simulated

Model concept: Carbon cycle

DIC

Pdiat

Pnano

Zmicro

Zmeso

DOC

POC

GOC

1

2

3

4

6

5

7

9

10

8

11

11

Model configuration:

Physics:



NEMO3.4

Biogeochem

ics
:

PISCES

Area:



North Atlantic





20S to 80N

Resolution:


1/4
°

Simulation:


1978
-
2010



Major fluxes:

1

Primary Production



New Production



[100m integrated annual avg.]


2+3

Zoo Grazing

4+5

Mortality

6
-
8 Plankton losses

9

Nitrification

10

Remineralisation

11
Carbon Export

[at 1000m, annual average]

11

Validation of model variables

Validation: Surface Nitrate annual cycle (log 10 )

WOA09

MODEL

Validation of model variables

Validation: Ratio of Diatoms and
Nanoplankton

PHYSAT

MODEL

Validation of model variables

Validation: Carbon export at 100m (
gC
/m2/
yr
)

Schlitzer

MODEL

SPG and STG have contrasting environment

UP or DOWN: regional variability

STG

s
ubtropical
gyre

SPG

subpolar

gyre

NECS

Europ
. Shelf

GST

Gulf Stream

CUW

Canary Upwelling

Sea surface temperature

F
-
ratio shows higher pelagic production in the Northern NA and SPG

UP OR DOWN:
NewP

: TPP (f
-
ratio)

Highest f
-
ratio in SPG, very strong correlation in
Canarian

Upwelling and STG

UP or DOWN: regional variability

STG

SPG

NECS

GST

CUW

avg

= 0.69



p = 0.61

avg

= 0.41



p = 0.89

avg

= 0.34



p = 0.99

avg

= 0.38



p = 0.93

avg

= 0.33



p = 0.58

New P (y)

--------------

TPP (x)


[
MolC
/m2/y]

High ratio in Labrador Sea

UP OR DOWN
ep
-
ratio: Export (1000m): TPP

Export highest in SPG, and strong correlation in CUW and STG

UP or DOWN: regional variability: Carbon export at 1000m

STG

SPG

NECS

GST

CUW

Export (y)

--------------

TPP (x)


[
MolC
/m2/y]

avg

= 0.15



p = 0.02

avg

= 0.09



p = 0.55

avg

= 0.04



p = 0.98

avg

= 0.05



p = 0.95

avg

= 0.06



p = 0.71

Increased TPP is followed by increased grazing and export except in SPG

UP or DOWN:
interannual

variability

TPP




PHY

ZOO


GRAZING



EXPORT

GST



SPG



STG



NECS



CIW

1990
-
2010

1990
-
2010

1990
-
2010

1990
-
2010

Provinces: Clustering

Longhurst

provinces based on physical/
biogeochmical

variables

CLUSTER: Export (1000m) and TPP

Differences in the structure compared to upper layer dynamics

CLUSTER: Grazing and TPP

Regional differences in the structure of coupling to export

Background

P

DIC

Z

Fish

D

Deep Sea

CO
2

storage

fisheries

Carbon export

Food web

Remineralisation

Sedimentation

UP

or

DOWN

OUTLOOK the role of zooplankton

Background

P

DIC

Z

D

Deep Sea

CO
2

storage

fisheries

Carbon export

Remineralisation

Sedimentation

UP

and

DOWN

OUTLOOK the role of zooplankton

Vertical

migration

Fish

Food web

Conclusions

THANK YOU

for your interest

.

This work was done
within the FP7 program



Basin
-
Scale Analysis ,
Synthesis and Integration



We would like to thank

-
TANGGO consortium:

travel support

Different biological processes,
e.g. zooplankton behavior, can
influence these ratios.


How much of Primary Production is
transported to the deep ocean (carbon
export)?

Export at 1000m is ca. 5
-
15% of PP in
upper 100m, while New Production is
highest in the northern North Atlantic.


What are regional differences in the
carbon transport and how do they change
during the 1990
-
2010 period?

Dynamics in SPG are significantly different
to STG and other regions.

Coupling of PP and EXP in the STG and
for PP and Grazing in most regions.
Strong decoupling in SPG.


What is the structure of the links of primary
production and carbon export in the North
Atlantic Ocean?


Grazing lowest in SPG, all other regions show strong correlation

UP or DOWN: regional variability

STG

SPG

NECS

GST

CUW

Grazing

--------------

TPP


[
gC
/m2/y]

avg

= 1.01



p = 0.59

avg

= 1.17



p = 0.98

avg

= 1.38



p = 0.99

avg

= 1.25



p = 0.99

avg

= 1.30



p = 0.98