The Pattern of South Equatorial Current and Primary Productivity in

South Java Seas

Rizky M. Utamy 1

, Noir P. Purba 1, Widodo S. Pranowo

2 and Henhen Suherman

3

1 KOMITMEN Research Group, Padjadjaran University, Bandung, Indonesia

2 Department of Fisheries and Marine Sciences, Padjadjaran University, Bandung, Indonesia

3 P3SDLP, BALITBANG-KP, Jakarta, Indonesia

Abstract. South Equatorial Current flows throughout the year and be strong in The East Monsoon between

latitudes 10oLS–20

oLS, focus of this study lies at the changing patterns of SEC associated with water mass

around it. The aim of this research is to knowing the correlation between SEC with the distribution of

phytoplankton in these waters. The observation was conducted by looking at the conditions of horizontal and

vertical of the data main (the current and phytoplankton) and supporting data (temperature and salinity) in

time series during 2014 using INDESO’s data. Result from this observation showed that the correlation

between SEC and primary productivity exists although known as a weak correlation. Other than that, SEC is

known have some spatial and temporal variations in every season as well, which is located at the northern

latitude during Eastern Monsoon in a range 5oS-15

oS for latitude and 90

oE-113

oE for longitude, and SEC

will be located at the southern latitude during First Transitional Season with range 8oS-18

oS for latitude and

90oE-115

oE for longitude.

Keywords: SEC, primary productivity, phytoplankton, velocity

1. Introduction

Eastern Indian Ocean Waters has typical characteristic influenced by the movement of monsoon and

trade wind systems [1] with the maximum velocity occurred during the Eastern Monsoon [2], [3], the

fluctuation of South Java Current (SJC) [4], [5] with the salinity ranges 33.8 PSU [4], Indonesian

Throughflow (ITF) with salinity and temperature ranges 34.4 PSU and 29oC [6], [7] and eddies system [8].

One of the streams that centralized in Eastern Indian Ocean is SEC. SEC be the one that linked Indian Ocean

and Atlantic Ocean and directly associated with world system current by Ocean Conveyor Belt (OCB) [9],

[10]. The study about water masses in Eastern Indian Ocean have been done either by the observation as well

as the models by [11], [12], [13], [9], [14]. Focus of this study is in the changing patterns of SEC associated

with the water masses around it. It is highly influenced by the dominance of ITF, SJC, and the stress wind

prevailling seasonally and effect the changes of nutrient distribution around Indonesian and Australia Waters.

South Equatorial Current flows throughout the year [11] and be strong in The Easterly Monsoon [14] at

10oLS–20

oLS for latitude and directly related to heat flux, salt transfer, and nutrient trap. SEC is one of

shallow current that have velocity about 0.15 m s-1

[12] and the depth is less than 200 m. The strong

incoming westward of SEC due to strengthening of ITF and the backflow in south Java [15]. SEC has its

own-characteristic which is has lower salinity than other water masses surrounded due to overflow of ITF

flowing to Indonesia [13]. This current has temporal variations influenced by the season and spatial

variations causing a shift of latitude as well. The study of dynamic in Eastern Indian Ocean and the

correlation with SEC more dominated in the spatial, zonal, temporal variability as well and has not been

discussed about its associated with primary productivity.

Corresponding author. Tel.: +622287701519; fax: +622287701518.

E-mail address: rizkymahrizautamy@gmail.com.

International Proceedings of Chemical, Biological and Environmental Engineering, V0l. 90 (2015)

DOI: 10.7763/IPCBEE. 2015. V90. 24

152

2. The Observation

2.1. The processing of INDESO data

The studies of this research are an area of South Java waters with coordinate 5oLS – 20

oLS and 90

oBT –

130oBT (Fig. 1). The method is conducted by taking and processing the data of current and phytoplankton

that obtained from INDESO (Infrastructure Development of Space Oceanography) model during 2014 from

website www.indeso.web.id with delayed mode. The data of INDESO has 0.88o as its resolution and

available in daily composite then processed into monthly average data. After that, both of data that have

become monthly average data processed spatially and temporally to find out the patterns of SEC and the

primary productivity condition in this waters.

Fig. 1: Area of SEC

3. Discussion

3.1. Current

According to the result of INDESO data processing during 2014 in South Java wares with coordinate

5oS-20

oS and 90

oE-130

oE then known that SEC experiencing the maximum velocity during the Eastern

Monsoon with a value about 0.0150 m/s as well as temperature and salinity have each values about 29oC and

34 PSU. The minimum velocity of SEC is known occurs during Western Monsoon with a value about 0.0049

m/s as well as temperature and salinity have each values about 31oC and 35 PSU. Range of SEC velocity,

temperature, and salinity in every month can be seen in Table 1.

Table 1: Range of SEC Velocity, Temperature, and Salinity during 2014

Months SEC Velocity (m/s) Temperature (oC) Salinity (PSU)

Maximum Minimum Maximum Minimum Maximum Minimum

January 0.0084 0.0028 31 27 34.6 33.8

February 0.0049 0.0027 31 26 35 33.6

March 0.0086 0.0033 32 27 34.8 32.5

April 0.0124 0.0040 31 27 35 32.5

Mei 0.1100 0.0039 30.5 26 35 32.5

June 0.0094 0.0041 30 25 34.5 31.5

July 0.0095 0.0034 29 23 35 33

August 0.0096 0.0041 29 23 35 32.9

September 0.0150 0.0046 29 24 34 34

October 0.0141 0.0037 29 24 35 33.8

November 0.0110 0.0029 31 25 35.2 33.8

December 0.0063 0.0028 31 25 35.3 33.8

Moreover, SEC is known to have some variations and changing patterns in every season as well. SEC is

located in the northern latitude during Eastern Monsoon with 5oS-15

oS for latitude and 90

oE-113

oE for

153

longitude, and SEC will be located in the southern latitude during Transitional Season I with 8oS-18

oS for

latitude and 90oE-115

oE for longitude. The conclusion of variations and changing patterns of SEC during

2014 can be seen in Fig. 2 and Table 2.

Fig. 3: Patterns of Current and Primary Productivity during 2014

3.2. Primary productivity

154

The phytoplankton processing data from INDESO 2014 in South Java waters showed that the

distribution of phytoplankton most abundant during Eastern Monsoon (September) with the maximum value

reaching 2 mmol C m-3

and 0.23 mmol C m-3

for the minimum value. The result showed that the abundance

of phytoplankton known to be in minimum condition when Transitional II Monsoon (December) occurs

reaching 0.8 mmol C m-3

for maximum value and 0.2 mmol C m-3

for minimum value. It means the primary

productivity in SEC waters of South Java known be the most abundance when Eastern Monsoon occurs and

decreased during Transitional Monsoon II. The value of primary productivity in SEC waters for 1 year can

be seen in Table 3 and the distribution of primary productivity in a year can be seen in Fig. 3.

Fig. 2: The Area of SEC Latitude and Longitude during 2014 Seen from All Seasons; Red is Transitional I Season; Blue

is Western Season; Black is Transitional II Season; Green is Eastern Season

Table 2: The Variations and Patterns of SEC during 2014

Seasons The Conditions of SEC

Latitude Range of Latitude (Km) Longitude Range of Longitude (Km)

Western 8oS – 16oS 888 90oE - 117 oE 2997 Transitional I 8oS - 18oS 1110 90oE - 115oE 2775

Eastern 5oS - 15oS 1110 90oE - 113oE 2553

Transitional II 7oS – 17.5oS 1165.5 90oE - 115oE 2775

Table 3: Primary Productivity in SEC Waters during 2014

Months Primary Productivity (mmol C m-3)

Maximum Minimum

January 1 0.2

February 2 0.19

March 2 0.2

April 2 0.19

Mei 2 0.21

June 2 0.22

July 1.3 0.2

August 2 0.2

September 2 0.23

October 2 0.198

November 1.4 0.21

December 0.8 0.2

4. Conclusion

From the results of observation concluded that SEC be in dominant phases when Eastern Monsoon

occurs with the velocity value is reaching 0.150 m/s as well as the value of temperature is 29oC and 34 PSU

for salinity. SEC is known to has some variations and the different changing patterns in every season. The

155

patterns of SEC will be located to the northern latitude during Eastern Monsoon, and will be located in the

southern latitude during Transitional I Season. Besides that, from the result of the observation can be

concluded that the productivity in SEC waters reaching the highest abundance during the Eastern Monsoon

with the maximum values is about 2 mmol C m-3

and the minimum value is about 0.23 mmol C m-3

.

5. Acknowledgements

The Authors would like to thank Padjadjaran University especially Marine Science Program, Fisheries

and Marine Sciences Department-Padjadjaran University, and KOMITMEN Research Group who have

supported the workmanship of this paper. The Author would like to thank P3SDLP, BALITBANG-KP North

Jakarta as the place to processing and analysing the data as well and to BPOL Bali for the opportunity of

JUVO Cruise 2015 that given to the Author.

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156

Author Index

A

Al-Ashraf Abdullah Amirul 16

Alexander Onuchin 132

Amirhossein Ashouri 36

Analiza P. Rollon 127

Anastasia Musokhranova 132

Ashok N. Bhaskarwar 82, 101

B

Bahareh Sadhezari 36

Benjamin Brigaud 22

Bhaskar Naik 51

Bin Li 8

Bo Jin 1

Bomi Kim 94

C

Camille Pasquet 22

Chan Jin Park 146

Chenglong Shi 63, 76

Christine Laporte-Magoni 22

Christophe Durlet 22

Conghui Gu 8

D

Da-Young Nam 140

Dmitri Prisov 132

E

Euijong Lee 94

Eun Ji Woo 146

Evans Chirwa 121

F

Fabrice Monna 22

Fanglong Qiu 63, 76

G

Garima Dwivedi 82, 101

Georg Guggenberger 132

Guncha Munjal 82, 101

H

Hak-Ho Nam 140

Hana Vodičková 43

Heekyung An 59

Henhen Suherman 152

Hu Zhang 1

Hyungsoo Kim 94

Hyun-Jeong Park 140

I

Ivana Šestáková 43

J

Jaehun Kim 94

Jana Jaklová Dytrtová 43

Ji Ye Yoo 146

Jia Yongzhong 70

Jin Yong Choi 146

Jinghe Sun 63

Jongmin Kim 59

Jordan, H.D. Chiswell 87

K

Kaili Liu 8

Kangwon Lee 59

Kazuhiko Miyanaga 127

Kesaven Bhubalan 16

Khushbu Patel 51

Kaswandi, M.A. 114

L

Lian, H.H. 114

Li Danqing 108

M

Mailin Misson 1

Min Jung Jeon 94

Min-Gyeong Gu 140

Min-Jeong Gu 140

Miroslav Gál 43

Mohamad-Azran Faris Mohamad

Azemi 16

Mohd Effendy Abdul Wahid 16

N

Nur Hayatul Akmal M.R. 114

Nur-Hidayah, H. 114

Noah, M. R. 114

Nang Hein Nandar Htwe 127

Nirendra M Misra 51

Noir P. Purba 152

Noor-Fazielawanie Mohd Rashid 16

P

Pauline Le Monier 22

Peggy Gunkel-Grillon 22

O

Qiu Fanglong 70 157

R

Rakshith R Shettigar 51

Rémi Losno 22

Rasyidah, T.I. 114

Rizky M. Utamy 152

S

Shanshan Sun 28

Shaolei Xie 63, 76

Shi Chenglong 70

Sun Jinhe 70

T

Taejin Hwang 59

Tamara Burenina 132

Terri-Ann Berry 87

Tian Yuan 108

Tomáš Navrátil 43

W

Wenqi Zhong 8, 28

Widodo S. Pranowo 152

Woojin Kim 59

X

Xia Yiping 108

Xie Shaolei 70

Y

Yan Jing 76

Yasunori Tanji 127

Yongzhong Jia 63, 76

Z

Zack Khuzwayo 121

Zhou Lei 108

Zhulin Yuan 8, 28

158