geotraces research in the western pacific marginal seas ......2013/07/09 · marginal seas-key...

GEOTRACES research in the western Pacific marginal seas and implications for the Indian Ocean biogeochemistry

Prepared by Meixun Zhao & Minhan Dai,

On Behave of the Asia GEOTRACES community (Jing Zhang, Tung-Yuan He, Jingling Ren, Pochao Xu,

Rujun Yang, Pinghe Cai, Guizhi Wang, Deli Wang, Jinzhou Du)

July 10, 2013, Lijiang

1

Outline

• Introduction to GEOTRACES

• GEOTRACES -western Pacific marginal seas: key questions

• GEOTRACES -western Pacific marginal seas: activities and results

• Implications for Indian Ocean biogeochemistry

2

An International study of the marine biogeochemical cycles of trace elements

and their isotopes

http://www.geotraces.org/

Scientific Committee on Oceanic Research

International Council for Science Sponsored by

And many national agencies. 3

Mission

Guiding mission To identify processes and quantify fluxes that control the distributions of key trace elements and isotopes (TEIs)in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions.

4

Philosophy and Motivation Disciplinary Focus Sources, sinks and internal cycling of trace

elements and their isotopes Global Sections Interdisciplinary Benefits/Objectives Biogeochemical cycles of essential

micronutrients

Proxies to reconstruct past ocean conditions

Tracers of ocean processes on time scales not amenable to direct measurement

Rates and tracers of carbon cycle processes

Transport and fate of contaminants

5

Themes

Program Themes Theme 1: Fluxes and processes at ocean interfaces Atmospheric deposition Continental run-off The sediment-water boundary Ocean crust Theme 2: Internal cycling Uptake and removal from surface waters Uptake and regeneration in the sub-surface ocean Regeneration at the seafloor Physical circulation Theme 3: Development of proxies for past change Factors controlling ‘direct’ proxy distribution in the ocean Factors influencing the distribution of ‘indirect’ proxies in the ocean Palaeoceanographic tracers of sediment flux and circulation

6

Sections

SCHEMATIC (!) ocean sections for GEOTRACES

Sections will be designed to investigate regions where targeted processes dominate trace element cycles.

7

Australia

Canada (white)

China

Japan

Korea/Japan

New Zealand

Taiwan

U.S.

Tahiti Easter

Island

Hawaii

Proposed GEOTRACES Pacific Sections 8

Outline





9

GEOTRACES-western Pacific and its marginal seas-key question:

Ocean response to terrestrial inputs

• To quantify the fluxes of land-based input into the Western Pacific and its marginal seas and to examine their significance as a contrast to oceanic/hydrothermal sources.

• To examine trace elements/isotopes (and their indication) of ocean margins-open ocean exchange?

• To identify major processes that modulate the behavior, bioavailability, fate and changes of land-based trace elements, as well as their interaction with biogenic elements

10

EQ

10°S

10°N

20°N

30°N

40°N

100°E 120°E 140°E

ASIA

Sea of Japan

South China Sea

East China Sea

Celebes Sea

Flores Sea

PACIFIC

NEC

NECC

MC

KC

Importance:

• Water Exchange

• Indonesian throughflow

• Warm pool & El Nino

Characteristics:

• Abundant river, SGD & dust input

• Complex geometry

• Steep topography

• Monsoon winds

• Strong currents

• human

11

Outline



• GEOTRACES -western Pacific marginal seas: highlights of activities and results


13

Co

0.00

0.05

V

0.00

0.05

0.10

0.15

Zn

0

5

10Cd

0.0

0.1

0.2

Ni

0

1

2

3

Aeolian deposition

Sinking particles at 30m

Cu

m

ol

m-2

d-1

0

5

July2007

October

2007

July2007

October

2007July2007

October

2007Pb

0.0

0.5

1.0

Ho et al. 2010 L&O

Fluxes and processes at ocean interfaces: Atmospheric deposition

Dissolved Al – dust storm

April 2007 Mar.31-April 1, 2007 -70

-60

-50

-40

-30

-20

-10

De

pth

(m

)

200703_Section A_Al (nmol/L)

A1 A2 A3 A4

40

70

100

130

160

190

(Ren et al., Matrine Chemistry, 2011)

Dust storm：114.9 mol Al m-2 day-1

Non-dust storm：3.0 mol Al m-2

AlAlTAlatm MADJ ,

Fluxes and processes at ocean interfaces: Atmospheric deposition

• Groundwaters;

• Sediment resuspension;

• Particle desorption;

• Industrial and municipal

sources

0

200

400

600

800

1000

1200

1400

1600

1800

0 2 4 6 8 10 12Salinity

Upper Rivers

Groundwaters

Coastline Waters

Estuarine Waters

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 2 4 6 8 10 12

Salinity

y = -3.39x + 33.0

r = 0.62

0

10

20

30

40

50

60

70

0 2 4 6 8 10 12Salinity

Dissolved

Mn

(nmol/L)

Dissolved

Cd

(nmol/L)

Dissolved

Cu

(nmol/L)

Summer 2009, Pearl River estuary

Wang et al., 2012,CSR

City of Guangzhou

Fluxes and processes at ocean interfaces: River inputs

Seasonal variations northern SCS June (summer) & December (winter) 2010

Ho et al. (submitted)


East China Sea (July 2010) Metals analyzed:

Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb

Liu, Gong, and Ho* (submitted)


Yellow River Estuary via radium isotopes (Xu et al., 2013, CSR)

1. River plume flowed mainly southeast at a flow rate of

5-7 km d-1, and a small portion flowed to the northeast

at a flow rate of less than 2 km d-1.

2. With this flow regime, nutrients were consumed

within 2 weeks by planktons to support an average primary

production of 0.14 g C m-2 d-1.

3. The estimated SGD flux was at least 3 times higher than

the Yellow River discharge, and its associated nutrients

were at least 5 times higher than river input.

Fluxes and processes at ocean interfaces: SGD

Northern South China Sea(NSCS) June-August, 2008

Pearl River

NSCS continental shelf

Flow rate: 1.8

TOC: 2.5

DIN: 2.1

DIC: 18

Flow rate : (km3 d-1) Material flux : (×108 mol d-1)

Flow rate: 0.3 (17%)

TOC: 0.4 (16%)

DIN: 0.2~0.7 (21%)

DIC: 4~9 (35%)

Flux

TOC/DIN: 1.4~2.8 DIC/TAlk: 1.03~1.46

TOC/DIN: 6~273 DIC/TAlk: 0.85~0.87

Groundwater TOC/DIN: 0.1~0.5 DIC/TAlk: 1.06~2.37

Flux

Q Liu 2012

The Changjiang dilute plume

120.5 121 121.5 122 122.5 123 123.5 12429

29.5

30

30.5

31

31.5

32

32.5

33

XLJ

1 2 3 4 5 6 7 8

9

10111213141516

17

18 19 20 21 22 23 24

25

26272829303132

33

34 35 36 37 38 39 40

41

424344454647

49

51 52 53 54 55 56

8C

5C

121.9 121.94 121.98 122.02 122.06 122.131.44

31.47

31.5

31.53

31.56

31.59

Chongming Island

122.3 122.41 122.52 122.63 122.74 122.8530.6

30.65

30.7

30.75

30.8

30.85

30.9

Shengshan

Huaniao

8C

Shengsi Islands

N

E

b

c

N

E

a

Shanghai

Hangzhou Bay

Inner plume

Outer plume

Inventory 224Raxx

(1012 dpm)

226Raxx

(1012 dpm) (d)

(1011dpm d-1)

The inner

plume zone 5.0 3.0 5.4 5.5

The outer

plume zone 2.8 3.8 7.0 5.5

The SGD flux in the CEP is estimated to be

0.2-1.0×109 m3 d-1 Gu et al., 2012, CSR


Jiulong River

SGD was the highest in the summer and lowest in the winter, but

the seasonal difference was less than 20%.

Wang GZ, unpubulished data


Distributions of 224Ra in the surface water (the unit in dpm 100 L-1) in the (a)

summer of 2009, (b) fall of 2010, (c) spring of 2011, and (d) summer of 2012

Wang GZ, unpubulished data


Zhujiang River

Horizontal distributions of dissolved Al at isopycnal surfaces.

Cross shelf transport of terrestrial material

0 10 20 30 40 60 80 100

DAl (nM)

22

20

27

26

25

24

23

Sig

ma

F1

F2

F3

F5

E5

D7

C9

G5

Depth=20-50m

J5

(Ren et al., submitted)

Trace elements/isotopes margins-open ocean exchange

Dissolved Al – phytoplankton bloom

0 20 40 60 80 100 120

Z4d Drift Station Al (nmol/L)

-70

-60

-50

-40

-30

-20

-10

0

De

pth

(m

)

18

20.5

23

25.5

28

30.5

33

Yellow Sea（spring of 2009）

Drifting observation during spring bloom

(Li, Ren et al., Chinese Science Bulletin, 2012)

120 121 122 123 124 125 12633

34

35

36

37

38

B1

B32 B31

B30 B29

B28 B27

B26 B25

B24B23

B22

B21

B20B19

B18

B17

B16 B15

B14B6a

B6

B5

B4

B3

B2

Yellow Sea

d

7 7.5 8 8.5 9 9.5 10Temperature (oC)

-80

-60

-40

-20

0

Dep

th (

m)

32.69 32.7 32.71 32.72 32.73 32.74

Salinity

11.2 11.6 12 12.4 12.8 13.2

SiO32- (mol/L)

12 16 20 24 28 32Al (mol/L)

0 4 8 12 Chl a (g/L)

T

S

Si

Al

Chl a

200903 Z4 Drift Station

7.2 7.6 8 8.4 8.8 9.2

-80

-60

-40

-20

0

Dep

th (

m)

32 32.4 32.8 33.2

0 4 8 12 16

8 10 12 14 16

0 1 2 3 4 5 6

200903 Z11 Drift Station

Major processes that modulate the behavior, bioavailability, fate and changes of trace elements

南海海盆SEATS站d30SiSi(OH)4和d30SiBSi垂直分布

南海北部陆架至陆坡实测硅稳定同位素组成与稳态分馏模式计算结果比较

南海北部硅稳定同位素组成和变化主要由不同水团的物理混合（珠江冲淡水、垂直混合、水平输入）和不同程度的生物分馏（富营养 vs.寡营养）共同控制

Longitude (oE)

La

titu

de

(oN

)

109 111 113 115 117 119 121 12317

19

21

23

25

Mainland China

Pearl River

estuary

Luzon

wNP

SCS

A9

A5

A2

A10

SEATS

A7

2.3‰

2.5‰

2.8‰

Surface d30SiSi(OH)4 increased generally from the inner shelf to the deep basin, indicating increasing fractionation of Si isotopes during the transition from eutrophic to oligotrophic conditions induced by the presence or absence of various nutrient sources in the NSCS.

Low degree of Si(OH)4 utilization caused by continuous rivering supply of weakly utilized Si

More complete consumption of the lower amounts of available Si(OH)4

A precise mapping of 234Th, Chl-a, POC, and phytoplankton composition in the South China Sea

28

E403

E404

E405

E401

E402

E406

LE09SEATSLE05LE04a

D105D104

D103D102

DD201DD202DD203

E601

E603

E605

E607

A7A6

A5A4

A2

A1aA0

A10

S504

S503

S501S209

108 110 112 114 116 118 120 122

18

19

20

21

22

23

La

titu

de (

N)

LE00 LE01 LE02DD203

DD202DD201

D102D103

D104D105

LE04 LE05

E505

E503

E501E500

E601

E603

E605

E607

S206

S209S501

S503

S504

A10

A0A1

A2A4

A7A6

A5

SEATS LE09

E406

E405

E404

E403

E402

E401

108 110 112 114 116 118 120 122

18

19

20

21

22

23

La

titu

de (

N)

Spring

Summer

E601

E602

E603

E604

A7A6

A5A4

A2

E607

S209

A1

E605

SEATS

A0

A10

S504

S503

S501

108 110 112 114 116 118 120 122

18

19

20

21

22

23

La

titu

de (

N)

Autumn

E603

E602

E601QD02

E500a

E501a

E502a

E604

E605

E607

SEATS

A10

A0A1

A2A4

A5A6

A7S103

S501a

S503

S504

E406

E405

E404

E403

E402

E401

E400

108 110 112 114 116 118 120 122

Longitude (E)

18

19

20

21

22

23

La

titu

de (

N)

Winter

100 105 110 115 120 125

Longitude (E)

0

5

10

15

20

25

30

La

titu

de (

N)

South China Sea

P.R.China

Vietnam

Cai PH, unpubulished data

Major processes that modulate the behavior, bioavailability, fate and changes of trace elements

29

0.0

0.2

0.4

0.6

0.8

1.0

0.0

0.2

0.4

0.6

0.8

1.0

1.0

2.0

3.0

4.0

5.0

Spring

5 m

25 m

50 m

75 m

100 m

Summer

5 m

25 m

50 m

75 m

100 m

Autumn

5 m

25 m

50 m

75 m

100 m

Winter

5 m

25 m

50 m

75 m

100 m

234Th/238U (AR) Chl-a (µg l-1) POC (µmol l-1)

Cai PH, unpubulished data

Themes

Western pacific open ocean cruises

30

Northwestern Pacific

KH-10-2 Cruise (16 Jul – 04 Aug 2011; Chief scientist: J. Zhang)

Marine Biogeochemical Studies in the East Asian Marginal Seas

The first ASIAN GEOTRACES cruise

Clean sampling Clean sampling + kevlar

Trace elements: Y. Sohrin & H. Obata

Fe, Al, Zn, Mn, Cd, Cu

Radioactive isotopes: A. Okubo230Th, 231Pa

Stable isotopes: U. Tsunogai & M/-H. Dai

d15N, d13C

Radiogenic isotopes:

Nd and Pb isotopes

Particles/Aerosols: H. Minami/Y. Nakaguchi

Other parameters:

Sc, Ti , Se, Co, Ni, Pb, Zr, Nb, Hf, Ta, W, Mo, Pd, Pt, Au

d14C, dMo, dW, dCu, d236U

TDIC, POC, N-fixation, pigment etc.

Parameters

KH-11-7 Cruise (16 Jul – 4 Aug 2011; Chief scientist: J. Zhang)

• Japan GEOTRACES cruise (GP18), “Marine biogeochemical studies and behavior of trace elements and isotopes in the Western North Pacific”

• The second ASIAN GEOTRACES cruise

• In addition to the original section along 165°E, process studies were included on cold seep biogeochemistry and on earthquake mechanisms, and ocean radionuclide impact studies off NE Japan and Fukushima area.

• Radionuclide are using as powerful tracers for GEOTRACES program.

Trace elements:Fe, Al, Zn,Mn, Cd, Cu Y. Sohrin & H. Obata

Radiogenic isotopes:

Nd isotopes H. Amakawa

Pb isotopes Celine Gallon & A. R. Flegal

Radioactive isotopes: 230Th, 231PaStable isotopes:d15N, d13C

Particles/Aerosols: Y. Nakaguchi

Other parameters:

Sc, Ti , Se, Co, Ni, Pb, Zr, Nb, Hf, Ta, W, Mo, Pd, Pt, Au

d14C, dMo, dW, dCu, d236U

TDIC, POC, N-fixation, pigment etc.

Parameters

Cd

TR7_ Trace Metal (nM)

0.0 0.5 1.00

500

1000

2000

3000

4000

5000

6000

Pb

0.00 0.05

Al

5 10

Zn

0 5 10

Cu

0 1 2 3 4

Cr

0 1 2 30

500

1000

2000

3000

4000

5000

6000

Mn

0 1 2

Fe

0 1

Co

0.00 0.05

Ni

0 5 10

Triplicate samples

Ho (unpublished data) ; Analytical method: Ho et al. 2010

Trace metal profiles in the northwestern Pacific: Japan 2011 GEOTRACES cruise

• R/V Hakuho Maru left Tokyo on Aug and arrived at Vancouver (Canada) on Oct.• Thirty three scientists and students, including two graduate students from Korea and

Indonesia, participated the cruise• A zonal transect, a part of which was uncompleted due to bad weather, was undertaken

along ~47°N in the northern Pacific (GP02) aiming at establishing the first 2-dimensional profiles of GEOTRACES TEIs across the northern North Pacific to extract much information on biogeochemical cycles of TEIs

• Some radioisotopes associated with the accident at Fukushima nuclear power plant on March 11, 2011 were investigated

• In addition, submarine hydrothermal activity was examined at Juan de Fuca Ridge as a significant source of TEIs from lithosphere to seawater

KH-12-4 Cruise (23 Aug – 03 Oct 2012; Chief scientist: T. Gamo)

2013 Taiwan GEOTRACES Test

Cruise

Western Philippine Sea

2013.07.14~23

Cruise Map

38

• Date: July 14th ~ 23rd

• Stations: 1~8 (7 days)

• Mega Stations: 1, 3, 8

• Depth: down to bottom

Section map and cruise tracks in Pacific

Future cruises (by R/V Hakuho-maru)

P10

PI: T. Gamo

2014-15

P06

PI: J. Zhang

2015

XMU New RV with Clean Sampling Capacity: 2015

Outline





41

Several highlights

• A base station (20°S, 72°33’E) was established for future GEOTRACES collaboration and inter-calibration in the Pacific

• Multi-nation efforts: For both the Pacific and the Indian Ocean GEOTRACES cruises, interdisciplinary research

• Capacity Building: Multi-nations, multi-institutions

Suggestions for future GEOTRACES research in the western Pacific and the Indian Ocean – Elucidation of TEIs flux from the marginal sea to open ocean – TEIs behaviors/distributions and their variations controlled by

the multi-biogeochemical processes from the land to ocean – Strengthening the synergy between TEIs observation technique

development and data simulation/modeling

Specific suggestions: 1. Use of natural radium quartet to study SGD and River discharge

into the Bay of Bengal: stratification and serious hypoxia

2. Use of naturally occurring radioactive isotopes (e.g. radium, radon)

to quantify the mixing rate and upwelling

3. Multi-tracers to assess the flux and seasonal variations of the

Indonesian Throughflow

geotraces research in the western pacific marginal seas ......2013/07/09 · marginal seas-key...

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