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Pan-Arctic primary production: State-of-the-Art on estimation from ocean color remote sensing data

Marcel Babin

& Simon BélangerCanada Excellence Research Chair

« Takuvik »Joint Laval University / CNRS LaboratoryLaval University, Quebec City, Canada

Département de Biologie, Chimie et GéographieUniversité du Québec à Rimouski

Rimouski, Canada

And contributions from Flavienne Bruyant (CERC) and Yannick Huot (U. Sherbrooke)

Outline

1.

Description of our PP algorithm

2.

Discussion on limitations

3.

Results on magnitude and trends in pan‐ Arctic PP

Methods

–

Primary

production

Rationales

behind

our

Primary

Production Model

• « Case 1

»

optical

parameterizations

and algorithms are not valid

in the Arctic

Ocean

• A spectral approach

is

necessary

for light propagation and absorption by phytoplankton, because

of

competition

with

CDOM

and NAP

• An regional

parameterization

of photosynthetic parameters

must be

adopted

Methods

–

Primary

production model

Standard ocean

color

chl

products

are not reliable

in the Arctic

Ocean

Methods

–

Primary

production model

Standard ocean

color

chl

products

are not reliable

in the Arctic

Ocean

June

Methods

–

Primary

production model

Standard ocean

color

chl

products

are not reliable

in the Arctic

Ocean

Methods

–

Primary

production model

Globcolour

(1998‐2007)Monthly

GSM a

(443)Globcolour

(1998‐2007)Monthly

GSM a

(443)

ChlChl

Globcolour

(1998‐2007)Monthly

Lw

()Globcolour

(1998‐2007)Monthly

Lw

()

a

()a

()

Matsuoka et al. (2007)

Matsuoka et al. (2007) Lee et al. (2005)Lee et al. (2005)

SBDART

(RT

code)ISSCP

cloud

, [cloud], ozone)

SBDART

(RT

code)ISSCP

cloud

, [cloud], ozone)

K

d

()Kd

()

E

d

(, 0+, t)Ed

(, 0+, t)

E

d

(, z, t)Ed

(, z, t)

PUR(z, t)PUR(z, t) PUR(z)PUR(z)

Arrigo

et al. (1998)Arrigo

et al. (1998)

E

K

(PUR)EK

(PUR)P

b

max= 2Pbmax= 2

PP( z,t ) Chl PB

max 1ePUR( z ) EK ( PUR ) See www.globcolour.info

Photosynthetic

parameters

Arrigo and Sullivan (1994)

Photosynthetic

parameters

Rey (1991)

Barents Sea

Photosynthetic

parameters

Beaufort Sea

Num

ber

PBmax [mg C (mg chl a)-1 h-1] Ek (mole photons m-2 s-1)

~0.5 ~23

Photosynthetic

parameters

Methods

–

Primary

production model

Globcolour

(1998‐2007)Monthly

GSM a

(443)Globcolour

(1998‐2007)Monthly

GSM a

(443)

ChlChl

Globcolour

(1998‐2007)Monthly

Lw

()Globcolour

(1998‐2007)Monthly

Lw

()

a

()a

()


Matsuoka et al. (2007) Lee et al. (2005)Lee et al. (2005)

SBDART

(RT

code)ISSCP

cloud

, [cloud], ozone)

SBDART

(RT

code)ISSCP

cloud

, [cloud], ozone)

K

d

()Kd

()

E

d

(, 0+, t)Ed

(, 0+, t)

E

d

(, z, t)Ed

(, z, t)

PUR(z, t)PUR(z, t) PUR(z)PUR(z)

Arrigo

et al. (1998)Arrigo

et al. (1998)

E

K

(PUR)EK

(PUR)P

b

max= 2Pbmax= 2

PP( z,t ) Chl PB

max 1ePUR( z ) EK ( PUR ) See www.globcolour.info

Impact of pixels with

no OC data

Region

Considered Relative difference

between

PP with

OC only, and PP for

all ice‐free areas

All Arctic

waters ‐6.7%

> 60° ‐30%

Arctic

Basin ‐47%

Results

Latitudecriterion

This study Longhurst et al. (1995)

Behrenfeld & Falkowski (1997)

Antoine et al. (1996)

Pabi et al. (2008)

All Arctic (sensu IHO)

0.62* - - - -

>60° 0.46 - - - -

>66.5° 0.26 - - - 0.42

>70° 0.19 1.4 0.4 0.6 -

* Gt

C y‐1

Primary

Production

PP : GSM VS OC4v4 for year

2007Region GSM OC4v4 %diff

Greenland 51.9 65 25.2%

Norwegian 97.7 98.3 0.6%

Barents 70.9 80 13%

Kara 24.5 39.5 61%

Laptev 15.3 22 44%

East Sib Sea 16.5 22.7 38%

Chukchi 9.6 14 46%

Beaufort 6.7 11.3 69%

Baffin Bay 11.9 18.1 52%

Hudson Bay 18.3 27.3 49%

Arctic Ocean 14.2 22.4 57%

Circumpolar Arctic: 293 378 29%

Mean

Anuual

Primary

Production

Primary

Production trend

Ice

trend during

the last decadeSpring Summer

Trend in Chlorophyll

concentration

June July

What’s

next?

• To better document Arctic Ocean optical properties• To improve and validate algorithms• To address the DCM

problem

Zeu

ZmlZN

PPChl

The DCM

in the Arctic

Ocean

At lower latitudes In the Arctic Ocean

The DCM

in the Arctic

Ocean

Morel & Berthon (1989)

What’s

next?

• To better document Arctic Ocean optical properties• To improve and validate algorithms• To address the DCM

problem

• To further document phytoplankton photosynthesis• …

Thank

you!

Methods

–

Primary

production model

Arctic

waters are optically

dominated

by CDOM


Arctic

waters are optically

dominated

by CDOM

Babin et al. (2003)

560 nm

412 nm 490 nm

510 nm

443 nm

a

aCDOM aNAP

AtlanticAdriaticBalticEng. ChannelMediterraneanNorth Sea

Methods

–

Primary

production model

a

Methods

–

Primary

production model


a * is

generally

lower

in the Arctic

Ocean

because

of the light regime

Est

imat

edK

d(49

0) (m

-1)

Doron et al. (2007)

ResultsPrim

aryProd

uctio

n (Gt C

y‐1)

1.05 Gt C y‐1

1.03 Gt C y‐1

marcel babin simon bélanger - arcticnet › pdf › talks2010 › babinmarcel.pdfmarcel babin &...

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