Synthesis of Arctic PPI- Historical data

(field 14C-, chl-derived NPP)

Paty MatraiElise Olson

Bigelow Laboratory for Ocean SciencesJanuary 28-29, 2008

14C-PP: All data points, all depths, all times

Chl a: All data points, all depths, by season

Surface (0-5m) chl-NPP [mgC m-3 d-1], all years, seasonal

Surface (0-5m) 14C-NPP [mgC m-3 d-1], all years, seasonal

14C-NPP

Chl-NPP

Integrated (0-MLD) chl-NPP [mgC m-2 d-1], all years, seasonal

Integrated (0-MLD) 14C-NPP [mgC m-2 d-1], all years, seasonal

Surface (0-5m) NPP [mgC m-3 d-1], annual, 1954-200514C-NPP Chl-NPP

0.08 - 21.2 gC m-3 a-1 <0.003 – 2.3 gC m-3 a-1

Integrated (0-MLD) NPP [mgC m-2 d-1], annual, 1954-2005

14C-NPP Chl-NPP

0.07 - 304 gC m-2 a-1 0.07 - 304 gC m-2 a-1

Log Chlorophyll (mg m-3)

-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0

Lo

g D

aily

PP

(m

g C

m-3

day

-1)

-2

-1

0

1

2

3

4

Resolute BayChukchi BayBarents

1. Empirical chlorophyll based algorithmV. Hill

Combined dataset

ANCOVA

•Chl 0.8 – 32 mg m-3

•P < 0.01

Average Chlorophyll•Resolute Bay 8.1 mg m-3

•Barents Sea 4.2 mg m-3

•Chukchi Sea 1.2 mg m-3

Log PP = 1.36 + 1.0.Log Chl

?

14C-observed vs. chl-derived field NPP

Ob

serv

ed

Calculated

Comparison of Annual Integrated Averages [gC m-2 a-1]

60-70oN 70-80oN 80-90oNGreenland,Norwegian,WSpitzbergen,Chukchi,~Bering

Chukchi,Beaufort ESiberian, Laptev, Kara,Barents,Greenland,Labrador, Canadian A.,

Field 14C-NPP 1954-2005 MLD 108.27 76.49 68.53

Field Chl-NPP 1954-2005 MLD 76.13 21.34 20.69

Sat chl-NPP 1998-2007 Euph 61.36 29.27 13.82

PO4-NCP 1971-2005 26m 16.91 16.34 12.47

NO3-NCP 1971-2005 26m 15.30 15.51 0.50

Total High Arctic Sakshaug 2004

97, >230, 60-180

32, 97 >11

NO3 longer winter 12.15 12.88 2.17

Assumptions: # days growth season, integration depth, geometric mean, #years, daylength, mo. per season, scale up: d-1 -> a-1, C/N, ?

Comparison of Annual Surface Averages

gC m-3 a-1

60-70oN 70-80oN 80-90oN

Field 14C-NPP 1954-2005 7.02 3.38 4.24?

Field Chl-NPP 1954-2005 2.23 1.02 0.84

Sat chl-NPP 1998-2007 2.84 1.36 0.48

Average vertical profiles, 10o latitude bands, annual, 1954-2005

14C-NPP

chl-NPP

0

000

0020

80

20 20

80 80