‘Photosynthesis’ by Ursula Freer

Biological ProductivityMichael Behrenfeld

Characterize‘Conversion’

Detect Change

Forecast Variability ‘Ecosystem’

Total 100 Pg C y-1

Equally distributed

Varied fate, pool lifetime 85% ocean NPP rapidly respired 15% transported to abyss < 0.5% make it to sediments

Separation of photosynthesis and respiration/degradation

Atmosphere – Biosphere - Solid Earth Interactions

NPP = NDVI PAR { * g(T0) h(W) }NPP = Biomass Light Conversion Efficiency

NDVIAVHRR, SeaWiFS,

MODIS

PARISCCP

TemperatureNational Centers for

Environmental PredictionSoil MoistureNCEP Precipitation

Remote Sensing (future)

1982-19991992-1999

Decadal trends in Terrestrial vegetation

NOAA 11AVHRR

1980 200019901985 201020051995

NOAA 7AVHRR

NOAA 9AVHRR

NOAA 14AVHRR

SeaWiFS

SPOT

MODIS

NPP = Chlsat Zeu f (PAR)

Surface Chlorophyllk490

NPP = Biomass Light Conversion Efficiency

PAR SST

Ocean Productivity Estimates from 1919 to 2001Date Author NPP (Pg y-1) Method

1919 Schroeder 22 speculation1934 Zernov 60 not available1937 Noddack & Komor 29 one production measurement1944 Riley 126 O2 method (long incubation)1950 Skopintsev 50 based on sediments1952 Steemann Nielsen 20 few 14C measurements1957 Laevastu 20 FAO production data (O2, 14C, etc)1958 Fogg 32 FAO production data (O2, 14C, etc)1968 Koblentz-Mishke et al. 23 Synthesis of many 14C stations1969 Bogorov 25 Synthesis of many 14C stations 1969 Ryther 20 14C & spatial model1975 Platt & Subba Rao 31 new 14C synthesis1985 Shushkina 56 new 14C & biomass data1987 Martin et al. 51 revision of Koblentz-Mishke et al.1989 Berger et al. 27 new 1C synthesis1995 Longhurst 45-50 CZCS data & 14C calibration1996 Antoine et al. 47 CZCS data & 14C calibration1997 Behrenfeld et al. 44 CZCS data & 14C calibration1998 Field et al. 48 CZCS data & 14C calibration2001 Behrenfeld et al. 54 - 59 SeaWiFS data & 14C calibration

1980 200019901985 201020051995

CZCS SeaWiFS

MODIS

NPP

NO DATA

1998 1999 20003.5

4.0

4.5

5.0

5.5

6.0

1998 1999 20001.0

1.2

1.4

1.6

1.8

1998 1999 20000.6

0.8

1.0

1.2

1.4

1998 1999 20000.02

0.04

0.06

0.08

Atlantic

Indian

Mediterranean

Total

Spatial Basin Global

Model 1

Model 2

0 25 50 75 100 NPP (gC m-2 month-1) NP

P (

Pg

C/m

onth

)N

PP

(P

g C

/mon

th)

NP

P (

Pg

C/m

onth

)

NP

P (

Pg

C/m

onth

)Year

monthyear

day

decade

local

globalregional

IntegrationArea

Inte

grat

ion

Tim

e

Mo

de

l Div

erg

en

ceor

'Un

cert

ain

ty'

high

low

moderate

Divergence

Quantifying the Earth System….

0.01 0.1 1 10

1 10 100 1000

0.1 1 10 100

Re

lativ

e F

requ

ency

Euphotic Zone Chlorophyll

(mg m2)

Satellite Chlorophyll

(mg m3)

Light-saturatedPhotosynthesis

(mgC/mgChl/h)

National Science Foundation

International Programs

Light

Con

vers

ion

Eff

icie

ncy

Light

Con

vers

ion

Eff

icie

ncy

National Science Foundation

International Programs

Trebon, Czech Republic

0.01 0.1 1 10

1 10 100 1000

0.1 1 10 100

Re

lativ

e F

requ

ency

Euphotic Zone Chlorophyll

(mg m2)

Satellite Chlorophyll

(mg m3)

Light-saturatedPhotosynthesis

(mgC/mgChl/h)

National Science Foundation

International ProgramsC

onve

rsio

n E

ffic

ien

cy

Light

Light

Type I

Type II

National Science Foundation

International Programs

6 CO2 + 6 H2O + light C6H12O6 +12 O2

6 CO2 + 9 ATP + 6 NADPH C6H12O6 + 6 NADP+ + 9 ADP + 9 Pi

3 O2 + 6 NADPH + 15 ADP + 15 Pi 6 NADP+ + 6 H2O + 15 ATP

1 NO3 + 5 NADPH + 1 ATP + 1 -ketogluterate 5 NADP+ + 1 ADP + 1 Pi + 1 -amino acid

20

6 H2O + 6 NADP+ + 9 ADP + 9 Pi + light 6 O2 + 6 NADPH + 9 ATP

10

Forecasting Variability….

National Science Foundation

120o E

5o

15o

25o

35o

5o

15o

25o

5o

15o

25o

35o

5o

15o

25o

160o W160o E 80o W120o W

0.2

0.3

0.4

0.5

135 130 125 120 115 110 105 104 104 105 106

SPG EU SPG EU

Longitude

pc

8oN

8oS

4oN

4oS

1oN

125oW140oW

1oS

0

50

100

150

200

250

300

6/97 6/98 6/99 6/00

0

40

80

120

6/97 6/98 6/99 6/00

0

40

80

120

6/97 6/98 6/99 6/00

0

40

80

120

6/97 6/98 6/99 6/00

0

40

80

120

6/97 6/98 6/99 6/00

0

40

80

120

6/97 6/98 6/99 6/00

Pri

mar

y P

rodu

ctio

n(g

C/m

onth

x 1

07 )

Date Date

5oN-8oN

2oN-4oN

1oN-1oS

2oS-4oS

5oS-8oS

Prim

ary Production (gC

/month/bin x 10

7 )E

cosystem M

odel =

Con

version M

odel =

Ecosystem ModelConversion Model

TOTAL8oN-8oS

A new interdisciplinary study to test model performance….

Department of Energy

Central Points…

If collected from a ship, assuming a cruising speed of 10 knots and a sampling time of 1 hour per station, the same number of chlorophyll values would require 11 years to collect.

1) Productivity is a key index of ecosystem function and health

2) NASA’s unique perspectives support qualitative and quantitative characterization and detection of change.

3) Detection and prediction are vastly different problems, but they share a variety of requirements for process understanding

4) Cooperative NSF – NASA research is leading to breakthroughs in our fundamental understanding of Earth-system functioning