Influence of Changjiang discharge, resuspensionof sediment and eutrophication to chlorophyll variability in the Yellow Sea and East China Sea: Results from new satellite data set

Ishizaka, JojiXu YongjiuYamaguchi,

HisashiEko Siswanto

2nd Int. Sympo.Effects of

Climate Change on the World’s

Ocean (May 16, 2012)

Problems in YECS and possible causes• Giant Jellyfish (N. nomurai) 2002-2007, 2009• Red tide (C. polykrikoides) 1988-2005• Red tide (Prorocentram) 2000-• Green tide (Enteromorpha prolifera) 2008-

• Eutrophication (River, Atmos.)• Climate Change• Dam Construction• Overfishing• More

Chugoku News

Iwataki

Ocean Color Remote Sensing – Useful ToolHowever, problem of Turbidity

1998-2008 Average in January

50m

100m

Jan

Standard CHL

YOC CHL Difference

TSM (Yamaguchi et al. Submitted)

New Algorithm Developed by

Yellow Sea Large Marine Ecosystem

(YSLME)Ocean Color Project

(Siswanto et al. 2011)

Seasonal Change of New Chl-a(10 year average)

(Yamaguchi et al. Submitted)

Jan Apr

OctJuly

(mg m-3)

Seasonal Variation ofChl-a and TSM

YOC CHL

TSM

Spring Bloom

CDW

(Yamaguchi et al. Submitted)

1 2 3 4 5 6 7 8 9 101112

(B) South of ChangjiangHillock

0

2

4

6

8

0

2

4

6

8

10

12

14

BB

AA

CC DD EE

35

30

120 125

(Yamaguchi et al.,

Submitted)

Seasonal Variation

of Chl-a and TSM 1 2 3 4 5 6 7 8 9 101112

(A) Middle of Yellow Sea

0

2

4

6

0

2

4

6

8

10

SC

HL

(mg

m-3

)

10

12

14(D) Changjiang Hillock

1 2 3 4 5 6 7 8 9 1011120

2

4

6

8

0

2

4

6

8

Month

TS

M (

mg

l-1)

0

2

4

6

(E) East of ChangjiangBank

1 2 3 4 5 6 7 8 9 1011120

2

4

6

8

10

12

8 14

(C) Off Changjiang Mouth

1 2 3 4 5 6 7 8 9 1011120

2

4

6

8

0

2

4

6

8

10

12

14

SCHL

TSM

Month

High chl.a area and low salinity water

(Kim et al., 2009)

High Chl-a areas toChangjiang discharge with time lag

(Kim et al., 2009)

Interannual Variability of Chl‐a and Changjiang Discharge on May‐Oct.

(Yamaguchi et al.,

Submitted)

(Yamaguchi et al., PO-2012)

Area 16

Area 7

Area 14Area 15

Area 8

(mg/m3)

(m3 /s)

Chl

-a (m

g/m

3 )

Dis

char

ge (m

3 /s)

(Yamaguchi et al., PO, 2012)

Interannual Changes of SummerChl-a in Yellow Sea and Changjiang Discharge

Increase of Spring Maximum YOC SCHL

(A)黄海中央部

Eutrophication of Yellow Sea?

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0.0

0.5

1.0

1.5

2.0

2.5

Year

Chl

-a (

mg

m-3)

TS

M (

mg

l-1)

98 99 00 01 02 03 04 05 06 07

BB

AA

CC DD EE

35

30

120 125

Interannual Variation of Chl-a and TSM on Feb.-June（Middle of Yellow Sea）

(Yamaguchi et al., Submitted)

0

2

4

6

8

10

12

14

16

0

2

4

6

8

10

12

14

Year

Chl

-a (

mg

m-3)

TS

M (

mg

l-1)

98 99 00 01 02 03 04 05 06 07

BB

AA

CC DD EE

35

30

120 125

Increase of SCHL during May-June

TSM

CHL

Interannual Variation of Chl-a and TSM in Feb.-June（off Changjiang Mouth）

(Yamaguchi et al., Submitted)

YS China

Changjiang North

YS KoreaYS Middle

Use for Giant Jellyfish Bloom

Possible source areasof Medusa of N. nomurai

(Xu et al. In prep.)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

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11

seawifs 1997-2010

Modis 2008-2011 YS Middle

0.0

0.5

1.0

1.5

2.0

2.5

3.0

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4.0

4.5

Jan-

98

Jan-

99

Jan-

00

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05

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Jan-

11

Seawifs 1997-2010

Modis 2008-2010 YS Korea

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

Jan-

98

Jan-

99

Jan-

00

Jan-

01

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04

Jan-

05

Jan-

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11

Seawifs 1997-2011

Modis 2008-2010 Changjiang North

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

02

Jan-

03

Jan-

04

Jan-

05

Jan-

06

Jan-

07

Jan-

08

Jan-

09

Jan-

10

Jan-

11

Seawifs 1997-2011

Modis 2008-2010YS China

Chl

_a(m

g m

-3)

Extension to recent MODIS data(Xu et al. In prep.)

0

5

10

15

20

25

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

Mar Apr May Jun

0

5

10

15

20

25

1997

1998

1999

2000

2001

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2003

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2005

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2007

2008

2009

2010

2011

Mar Apr May Jun

0

5

10

15

20

25

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

Mar Apr May Jun

YS Middle

YS KoreaChangjiang North

JY NJYPJY

JYPJY NJY

NJYJYPJY

0

5

10

15

20

2519

9719

9819

9920

0020

0120

0220

0320

0420

0520

0620

0720

0820

0920

1020

11

Mar Apr May JunYS China

JYPJY NJY

SST variations in winter/spring months(Xu et al. In prep.)

SS

T(o C

)

Chl

_a(m

g m

-3)

0.0

0.5

1.0

1.5

2.0

2.5

Jan Feb Mar Apr May Jun Jul

1998_20012002_2007_20092008_2010_2011

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Jan Feb Mar Apr May Jun Jul

1998_20012002_2007_20092008_2010_2011

0.00.51.01.52.02.53.03.54.04.5

Jan Feb Mar Apr May Jun Jul

1998_20012002_2007_20092008_2010_2011

0.0

0.5

1.0

1.5

2.0

2.5

Jan Feb Mar Apr May Jun Jul

1998_2001

2002_2007_2009

2008_2010_2011

Monthly Chl_a in spring in PJY, JY, NJY

ChangjiangNorth

YS Middle

YS Korea

YS China

(Xu et al. In prep.)

Eutrophication

Interannual Variation of Changjiang Discharge

Chl Increase in Changjiang Mouth

Chl Variation off Changjiang Mouth

Variation of Upstream Rain Dam Construction

Chl Increase in Yellow Sea

Increase of Nitrate Decrease of Sediment Load

Ocean Color data Set

Giant Jellyfish Red Tide Green Tide

River DischargeAtmospheric Input

Climate Change(Cooling)

Conclusions• New ocean color data set (Chl-a and TSM)• Spring bloom after resuspension ceased• Bloom caused by summer Changjiang discharge• Summer Changjiang bloom – Changjiang discharge

interannual variation• Spring bloom/summer Chl-a in Yellow Sea and

Changjiang mouth – increasing – eutrophication –good environment for giant jellyfish

• Recent non-giant jellyfish bloom years – high spring bloom but colder

• Strobilation timing may be close to spring/summer blooms but the timing is different in location – detail study of the timing is on-going