Marine primary production estimates from ocean color - Joint Global

Marine primary production

estimates from ocean color�

a comparative study of algorithms

Mary�Elena Carr�� Marjy Friedrichs�

�Jet Propulsion Laboratory

California Institute of Technology

�Old Dominion University

PRIMARY PRODUCTION ALGORITHM

ROUND�ROBIN � �PPARR��

Our goal is to provide a framework to systematically

compare algorithms which estimate primary produc�

tion from ocean color�OUTLINE

�� Introduction

�� Approach

�� Results

Global� basin� chlorophyll� SST

Southern Ocean� region� SST

�� Conclusions and future work

RESULTS FROM PPARR�

PPARR� was a blind intercomparison to in situ data�

�� stations worldwide PP� �� g C m�� d��

The best�performing algorithms were within a factor

of �� There are systematic biases� which may be ad�

dressable by �netuning the model parameterization�

Best performance in regions which have contributed

historically more data� The equatorial Paci�c and

Southern Ocean data presented higher biases�

The algorithms were highly correlated among them�

selves� irrespective of complexity�

Acknowledgements

We thank all participants �list of groups on next page�

for their hard work�

We thank the Goddard DAAC and the SeaWiFS Project

for providing SST� chlorophyll and PAR data�

We also thank John Marra and Chuck Trees for their

support�

This research was carried out at the Jet Propulsion

Laboratory� California Institute of Technology� under

a contract with the National Aeronautics and Space

Administration�

PPARR�

PART �� Annual cycle �� Model output inter�

comparison�

PART �� Sensitivity analysis exploring biomass deter�

mination and parameterization of light utilization and

photo�adaptive physiology� Model intercomparison at

di�erent stages of PP estimation�

PART �� Comparison to in�situ ��C�uptake �ClimPP

�� tropical Paci�c stations�� Ground�truth compar�

ison�

�� David� IPCF� D� Antoine� B� Gentili and A� Morel�

�� Nick� BIO variant� N� Hoep�ner and F� Melin�

�� Kirk� K� Waters and B� Bidigare�

�� Tim� Modi�ed IPCF� T� Smyth and S� Groom�

� Mike� VGPM� M� Behrenfeld�

� Mike�� VGPM �Eppley PBopt�� M� Behrenfeld�

� ModisBF� VGPM� K� Turpie and W� Esaias�

�� Aurea� VGPM� A� Ciotti�

�� Joji� J� Ishizaka and Mr� Kameda�

�� Keith� K� Moore�

�� Heidi� Southern Ocean� H� Dierssen�

�� Heidi�� Southern Ocean chlorophyll� H� Dierssen�

�� Ichio� I� Asanuma�

�� Mark� Province�based� M� Dowell�

�� ModisHYR� HoYoRy� K� Turpie and W� Esaias�

�� RyYo� HoYoRy variant� J� Ryan�

� � HYRZe� HoYoRy variant �Ze�� M�E Carr�

�� Michele� Neural network� M� Scardi�

�� John� J� Marra�

�� SteveB� Hybrid WIM� VGPM PBopt� S� Lohrenz�

�� SteveB�� Hybrid WIM� VGPM PBopt� S� Lohrenz�

�� SteveA� Hybrid WIM� IPCF PBmax� S� Lohrenz�

�� OliCor� Ecosystem model� O� Aumont�

�� KeithE� Ecosystem model� K� Moore�

APPROACH

Given identical input �les �monthly mean�

Participants return integrated primary production�

m0 50 100 150 200

MLDJ

m0 50 100 150 200

MLDN

einstein m−2 d−10 15 30 45 60

PAR

oC

−1 9 19 29

SST

mg m−30.01 0.1 1

Chl

JAN

UA

RY

1998

g C m−2 day−10.1 0.32 1 3.2

MEAN MODELED PP

%0 25 50 75 100

STD AS % MEAN

Model spread quanti�ed as a function of �mean�

standard deviation of mean �x� as percentage

�xi � x��x� as percentage�

GLOBAL PRODUCTION

Mean global production for �� is �� Gt C y��

Standard deviation of the mean is �� Gt C y��

Range of model estimates is �� Gt C y��

LOW� �� Gt C y�� models

HIGH� � � Gt C y�� models� ��E

INTERMEDIATE� �� Gt C y�� models� ��E

No VGPM or Spectral variant is in the high level� ��

models of each kind are found in the low level�

5 10 15 20

35

40

45

50

55

60

65

70

75

VGPMSpectral

DINTEcosystem

Gt C

y−1

MEAN GLOBAL PRODUCTION 1998

Spectral | VGPM Variants | DINT Variants | Ecosystem

BREAKOUT BY BASINS

BASIN AREA MEAN �� MIN MAX

� Gt C y��

Paci�c ��

Atlantic ��

Indian ��

Southern ��

Arctic ��

Med� ��

Variability in model estimates has maximum impact in

small basins and in the Southern Ocean�

5 10 15 20

10−1

100

101

AN

NU

AL

PR

OD

UC

TIO

N /

Gt C

y−

1

Model number

Integrated Production

PacificAtlanticIndianSouthernArcticMed.

5 10 15 20

100

102

% O

F T

OT

AL

|SPECTRAL VGPM DINT| ECO|

PACIFIC−Inf −Inf 55 54−Inf −Inf

−76 −Inf −Inf 52 55−63 −Inf −Inf 57 52−65 −Inf −Inf 54

−Inf −Inf−Inf −Inf

159

12ATLANTIC


−72 −Inf −Inf 54−58 −Inf −Inf 59−60 −Inf −Inf


159

12INDIAN

Mon

th o

f 199

8

−Inf −Inf 63 59−Inf −Inf 51 51 65

−77 −Inf −Inf 73−62 −Inf −Inf 77−66 −Inf −Inf 59

−Inf −Inf 62−Inf −Inf 64 52

159

12SOUTHERN OCEAN

−Inf −Inf −52 59−Inf −Inf −56 57

110 −61 −Inf −Inf −56 99 72−60 152 −Inf −Inf −56 −52 101 103

173 −55 −Inf −Inf 50 −53 −51 56 10082 −Inf −Inf −56 90

−Inf −Inf 59 −56 63

159

12ARCTIC

−Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf190 109 −Inf −Inf 66 −74 −76 −87 −Inf −Inf −Inf 90 342

313 −Inf −Inf −79 −75 −86−54 284 −Inf −Inf 158 −86 −94 −87 −50

59 201 −Inf −Inf −79 −89 −91−Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf−Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf

159

12

% O

F M

EA

N

−100

−80

−60

−40

−20

0

20

40

60

80

100

MEDITERRANEAN61 −Inf −Inf −63 −9764 −Inf −Inf −61 −96

−75 51 −Inf −Inf 86 −69 −73 66 53 −97−54 −62 −Inf −Inf 96 −69 −79 56 56 −98

−59 −Inf −Inf 68 −60 −66 −98−54 61 −Inf −Inf −66 −97−50 59 −Inf −Inf −65 −96

SPECTRAL | VGPM | DINT | ECO5 10 15 20

159

12

�� models diverge in the Paci�c� Indian� Atlantic�

Seven �anomalous� models � high� low� in the South�

ern Ocean� Ecosystem models very high�

�� models are anomalous in the Arctic and Mediter�

ranean �small basins��

CONCENTRATION LEVEL

LEVEL AREA MEAN �� MIN MAX

� Gt C y��

Oligotrophic ��

Mesotrophic ��

Eutrophic ��

Models vary in relative importance of eutrophic and

oligotrophic waters �note spectral and ecosystem mod�

els and ��

5 10 15 2010

0

101

AN

NU

AL

PR

OD

UC

TIO

N /

Gt C

y−

1

Model number


OligotrophicMesotrophicEutrophic

5 10 15 20

101

102

% O

F T

OT

AL


OLIGOTROPHIC

−Inf −Inf 51 −54 66 71

−Inf −Inf −52 63 60

−83 −Inf −Inf 69 50

−72 −Inf −Inf 51 71

−74 −Inf −Inf 51 65 56

−Inf −Inf −51 61 67

−Inf −Inf 52 −55 62 73

1

5

9

12

MESOTROPHIC

Mon

th o

f 199

8 −Inf −Inf 52

−Inf −Inf

−74 −Inf −Inf 51 53

−61 −Inf −Inf 57

−63 −Inf −Inf 52

−Inf −Inf 53

−Inf −Inf 56

1

5

9

12

% O

F M

EA

N

−100

−80

−60

−40

−20

0

20

40

60

80

100

EUTROPHIC

55 −Inf −Inf −68 55 −57 −54

−Inf −Inf −66 62 −60 −55

−60 92 −Inf −Inf −54 −64 −53

69 −Inf −Inf −63 53 −65 −63

52 −Inf −Inf −67 61 −62 −56

−Inf −Inf −66 57 −62 −53

−Inf −Inf −65 −55

SPECTRAL | VGPM | DINT | ECO

5 10 15 20

1

5

9

12

General tendency to overestimate oligotrophic PP�

�� overestimates mesotrophic�

�� overestimate while �� and ECO underes�

timate eutrophic�

SST BINS

SST RANGE AREA MEAN �� MIN MAX

� Gt C y��

SST� �oC ��

�o � �oC ��

�o � ��oC ��

� ��oC SST ��

PP in SST��C is disproportionately lower than area�

Models di�er most ��C � and to a lesser degree ��C �

5 10 15 2010

−1

100

101

AN

NU

AL

PR

OD

UC

TIO

N /

Gt C

y−

1

Model number


<0o

0−10o

10−20o

>20o

5 10 15 20

100

102

% O

F T

OT

AL


SST<0oC

327 −Inf −Inf 81 −Inf −51 −78 120112 −61 −55 217 −Inf −Inf 58 −Inf −72 119 54

433 −Inf −Inf 135 −75 −54 −56 −51 59−55 −65 −65 −63 −63 −63 −61 −72 599 −Inf −Inf 323 −Inf −84 −93 −57 −71 77 −63 −65 −62 583 227

−53 182 218 −Inf −Inf −Inf −71 184 172132 −55 −53 218 −Inf −Inf 101 −Inf −64 310 6162 −54 292 −Inf −Inf 175 −Inf −71 357

1

5

9

12

0o>SST<10oC

Mon

th o

f 199

8

66 −Inf −Inf −59 −52 5486 69 −Inf −Inf −62

−54 94 −Inf −Inf −63−Inf −Inf −59

112 54 −Inf −Inf −62 55105 51 −Inf −Inf −60 −51 6463 58 −Inf −Inf −61

1

5

9

12

10o>SST<20oC

−Inf −Inf 51 56−Inf −Inf −51

−70 57 −Inf −Inf−52 64 −Inf −Inf−58 51 −Inf −Inf

−Inf −Inf−Inf −Inf 54 53

1

5

9

12

% O

F M

EA

N

−100

−80

−60

−40

−20

0

20

40

60

80

100

SST>20oC

−Inf −Inf 55 60−Inf −Inf 55 60

−78 −Inf −Inf 55 71−64 −Inf −Inf 60 59−66 −Inf −Inf 64 50 55

−Inf −Inf 53 54−Inf −Inf 55 51

SPECTRAL | VGPM | DINT | ECO5 10 15 20

1

5

9

12

SST ��C � nine models diverge� Many models un�

derestimate May or July� Ecosystem models overesti�

mate�

SST��C � �� and �� over��under�estimates

PP�

SST � ��C � �� and � overestimates�

REGIONAL PRODUCTION IN THE

SOUTHERN OCEAN

The uncertainty of the role of the Southern Ocean in

the carbon cycle is aggravated by the di�culties of

�eld sampling�

There is a disagreement between in�situ and satellite�

based estimates of production�

Mean production ��S� for � is �� Gt C y��

Standard deviation of the mean is � Gt C y��

Range of model estimates is Gt C y�� comparable

to the seasonal range for most models�

5 10 15 202

4

6

8

10

12

Model number

Gt C

y−1

MEAN SOUTHERN OCEAN PRODUCTION 1998


BREAKOUT INTO LATITUDINAL BANDS

Latitudinal circles following average frontal location

�Orsi et al �� Moore et al ��

REGIONS DEFINED BY FRONTAL POSITIONS

�� SubAntarctic Zone �SAZ�� S to SubAntarctic

Front �SAF�

a� North�Polar Front Zone �NPFZ�� SAF to Polar

Frontb� Polar Front �PF�� Within �� of the Polar Front�

c� South�Polar Front Zone �SPFZ�� Polar Front

to Southern Antarctic Circumpolar Current Front �SACCF��

�� South of the SACCF �SACCF�� South of the

SACCF subpolar waters and Weddell and Ross Seas�

SUMMARY OF MODEL PP

Mean model PP decreases with latitude� secondary

maximum in SACCF� Models diverge most moving

poleward�

0.1 0.2 0.3 0.4 0.5 0.6 0.7−70

−65

−60

−55

−50

−45

−40Model mean production for December 1998

g C m−2 d−1

Latit

ude

5 10 15 2010

−1

100

g C

m−

2 d−

1

Model number

December Production


SAZNPFZPFSPFZSACCF

�� and �� SAZ is minimum �� no di�erence�

Very low values south of PF ��

SOUTHERN OCEAN BREAKOUT IN SST

LEVELS

LEVEL AREA MEAN�� MIN MAX

� Gt C y��

��

��

�o��o ��

� ��o � ��

PP in SST ��C is approximately half of area�

5 10 15 2010

−2

10−1

100

AN

NU

AL

PR

OD

UC

TIO

N /

Gt C

y−

1

Model number

Integrated Production Southern Ocean

<0oC0o−10oC10o−20oC

5 10 15 2010

0

101

102

% O

F T

OT

AL


Relative apportioning same in all models� Greatest

divergence for SST��C �

SST<0oC

Mon

th o

f 199

8

310 97 71 −Inf −56 −79 107

115 −62 −56 192 −Inf −72 141

253 98 −65 −97 −55 −65 53 59 3.99e+032.02e+03

307 59 −70 −Inf −59 −67 4.69e+031.81e+03

−55 237 −52 −52 151 −Inf −60 −57 262 213

126 −57 −54 211 65 98 −Inf −64 298 51

57 −56 284 65 171 −Inf −51 −72 345

5 10 15 20

13579

1112

0o>SST<10oC

Mon

th o

f 199

8

78 −58 −56 61 51 61

75 76 −58 −62 67 54 72

170 −58 −60 −58 58 243 177

−58 191 −53 −65 95 −63 −61 395 288

214 54 −57 −62 64 117

135 77 −59 −56 85

69 73 52 −61 −53

5 10 15 20

13579

1112

% O

F M

EA

N

−100

−80

−60

−40

−20

0

20

40

60

80

100

10o>SST<20oC

Mon

th o

f 199

8

53 −59

−62

57 52 52 75 −51 −66

−71 121 55 −60 −57 81 −68 −52 102 91

−Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf −Inf

−63

51 −64 −51

MODEL NUMBER


5 10 15 20

13579

1112

Nine anomalous models in SST ��C �

�� uniformly high in SST��C � Model ��

was uniformly low everywhere and �� low SST�

��C �di�erent from global breakout �

Some models �e�g� �� counter the seasonal cycle�

other �e�g� �� reinforce it�

0 0.5−70

−68

−66

−64

−62

−60

−58

−56

−54Wavelength−resolved

Latit

ude

1=David2=Nick3=Kirk4=Tim

0 0.5

VGPM Variants

Primary Production /g C m−2 day−1

5=Mike6=Mike27=ModisBF8=Aurea9=Joji10=Keith11=Heidi12=Heidi2

0 0.5

Depth−integrated

13=Ichio14=Mark15=ModisHYR16=RyYo17=HYRZe18=Mich19=John20=SteveB21=SteveB222=SteveA

0 0.5

Ecosystem models

Primary Production /g C m−2 day−1

23=OliCor24=Keith

All model�types bracket the observations� a few �high�

values� tendency to underestimate�

Comparable� �� SPEC� �� and � �VGPM�

and �� and �� DINT� Ecosystem mod�

els not great�

0 0.1 0.2 0.3 0.4 0.5 0.6−72

−70

−68

−66

−64

−62

−60

−58

−56

−54

VGPM

Spectral

Other DIM

Ecosystem

TRANSECT AT 170oW, MARCH 1998

Primary Production/ g C/(m2 day)

Latit

ude

C14Mean

The mean of the modeled estimates is less than �but

� �� g C m��d�� the measured primary production

�Hiscock et al �� in all � regions�

VGPM variants tend to underestimate PP�

40 60 80 100 120 140 160−72

−70

−68

−66

−64

−62

−60

−58

−56

−54

−52

−50SEASONAL PRODUCTION ALONG TRANSECT AT 170oW

Primary Production/ g C m−2

Latit

ude

C14, Nelson et alPPModel, Buesseler et alMean 98, this studySPECVGPMDINTECO

Oct�May comparison for non�coincident years�

Model PP � C�� estimate � Optimized PP model

�except south of ��S��

Outlier models

Anomalies �H� L� are a function of the mean model�

A� P� I� S � basins�

T��T�� SST bins�

O� M� E� �chl�

S � Southern Ocean anomaly� s� SO and global

� anomaly only May�Sep� �boreal winter

A P I S T� T� T� T� O M E

� H Hs Hs

� L L L L L L L L

� Hs Hs H

� H H H H H H H

� Ls Hs L

� LS Hs

� L Ls Ls LS L

� H H

� L LS LS

�� H HS H

�� H L H H

�� H HS Hs H L

�� H HS Hs L

CONCLUSIONS

The spread between models is considerable �almost a

factor of ��

Peak disagreement for Southern Ocean� small basins�

SST ��C � and oligotrophic and eutrophic waters�

Generally divergence between models is greater mov�

ing south� and for waters ��C �

Comparison with concurrent March �� measure�

ments indicate tendency of models to underestimate�

Seasonal PP estimate is less than derived from C��

or from ocean color using a tuned parameter�

We need to use more Southern Ocean data to param�

eterize the models� Issues such as chlorophyll deter�

mination and parameterization of photosynthesis at

low SST are likely crucial�

Future work� Uncover the reasons behind these di�er

ences �Part �� and comparison to in�situ data �Part

��Stay tuned��

0 50 100 150 200

MLD JPL

SAZ

NAPFZ

PF

SAPFZ

SACCF

CONDITIONS IN 1998

1 3 5 7 9 11 12

0 15 30 45 60

PAR

SAZ

NAPFZ

PF

SAPFZ

SACCF

1 3 5 7 9 11 12

−2 2 6 10 14

SST

SAZ

NAPFZ

PF

SAPFZ

SACCF

1 3 5 7 9 11 12

0.1 0.18 0.32 0.56 1

Chlorophyll

SAZ

NAPFZ

PF

SAPFZ

SACCF

1 3 5 7 9 11 12

0.03 0.06 0.1 0.18

MEAN PP

SAZ

NAPFZ

PF

SAPFZ

SACCF

1 3 5 7 9 11 12

0 20 40 60 80 100

STD PP AS % MEAN

SAZ

NAPFZ

PF

SAPFZ

SACCF

1 3 5 7 9 11 12

MLD� SST� and PAR decrease with latitude�

Chl maxima in SAZ� PF� and SACCF�

Max PP in Jan and Nov�Dec� local minimum in SAPFZ

�Jan and Dec�� Minima in May�July�

Model spread at best �� increasing moving south

and in winter months�

SUBANTARCTIC ZONE

70 77 64−51 68 54

114 −58 59 −52 51 80 64−55 168 −51 79 97

173 −52 68 9470 57 −52 51

72 65 535 10 15 20

13579

1112

NORTH POLAR FRONT ZONE

60 −59 −55 −54 70 6090 56 −65 −54 −58 74 60 55198 −51 −78 −62 −52 −55 −57 61 157 125

−64 252 −85 −75 −62 90 −57 −63 347 290276 79 −59 52 −52 −62 97 153165 81 −54 −56 −56 9886 70 −54 −59 −52

5 10 15 20

13579

1112

POLAR FRONT

Mon

th o

f 199

8

86 −58 −55 59 5094 84 −56 −63 71 59 87216 63 −60 −57 −62 57 244 170

−62 272 −55 −68 97 −60 −66 668 489277 122 −55 −64 178 149163 111 55 −59 −57 12388 97 68 −61 −52

5 10 15 20

13579

1112

SOUTH POLAR FRONT

104 75 −57 −58 55 11896 113 −57 −64 64 52 134226 71 −64 −69 −57 −65 71 57 51 823 555

−51 286 −71 64 −62 −67 2.68e+031.54e+03−53 265 −54 −58 169 −59 −57 −57 326 283

142 150 85 −56 −59 −54 22891 133 95 −53 −60 −56 164

5 10 15 20

13579

1112

% o

f int

egra

ted

PP

−100

−80

−60

−40

−20

0

20

40

60

80

100

SOUTH OF ACC FRONT

MODEL NUMBER

Spectral | VGPM | DINT | Ecosystem

233 99.8 −57 −51 −68 193117 169 −64 −52 187242 88 −63 −96 −56 −64 67 53 61 1.58e+03835369 −50 −61 75 −70 −55 −56 −68 6.11e+032.03e+03

−58 264 −50 −56 −56 −75 −67 206 58 60 −98 −59 840 532132 −58 −58 −63 −66 344 210 −86 −67 1.44e+0315661 −58 325 62 219 −73 −72 689

5 10 15 20

13579

1112

Disagreement increases moving south�

Uniformly high �� or low ��

m0 50 100 150 200

MLD JPLCONDITIONS ALONG 170oW IN 1998

1 3 5 7 9 11 12

−70

−65

−60

−55

einstein m−2 d−10 15 30 45 60

PAR

1 3 5 7 9 11 12

−70

−65

−60

−55

oC

−2 2 6 10 14

SST

1 3 5 7 9 11 12

−70

−65

−60

−55

mg m−30.1 0.18 0.32 0.56 1

Chlorophyll

1 3 5 7 9 11 12

−70

−65

−60

−55

mg m−30.06 0.1 0.18 0.32 0.56 1 1.8

MEAN PP

1 3 5 7 9 11 12

−70

−65

−60

−55

%0 20 40 60 80 100

STD PP AS % MEAN

1 3 5 7 9 11 12

−70

−65

−60

−55

Progression as in Paci�c sector�

Maximum chlorophyll and PP in Jan south of ��Sand

in Dec in SAZ to ��S � Higher standard deviation of

models south�

Marine primary production estimates from ocean color - Joint Global

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