Seasonal variation of the upper-layer seawater properties in the Banda Sea: observed from an autonomous CTD Argo float

3rd EMBRIO International Workshop on Marine Biodiversity: Understanding, Utilization, Conservation

生态环境科学

Atmadipoera, A.S.^1 ; Prartono, T.^1 ; Jaya, I.^1 ; Nugroho, D.^2 ; Harsono, G.^3 ; Nanlohy, P.^4 ; Koch-Larrouy, A.^5

Department of Marine Science and Technology, Bogor Agricultural University, Bogor, Indonesia^1

Research and Development Agency, Ministry of Marine Affairs and Fisheries, Jakarta, Indonesia^2

Centre for Hydrography and Oceanography-Indonesian Navy, Jakarta, Indonesia^3

Faculty of Mathematics and Natural Sciences, University of Pattimura Ambon, Indonesia^4

Laboratoire d'Études en Géophysique et Océanographie Spatiales (LEGOS), Toulouse, France^5

关键词: Banda Sea;    Conductivity temperature depths;    Elliptical shapes;    Lateral variations;    Mixed layer depths;    Seasonal temperature changes;    Seasonal variation;    Upper layer;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/278/1/012008/pdf
DOI  :  10.1088/1755-1315/278/1/012008

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

An autonomous CTD (conductivity-temperature-depth) Argo float was deployed in the deepest Weber Basin of Banda Sea to investigate seasonal changes of the upper-layer seawater properties from the first year of CTD time-series data between August 2017 and July 2018. It is found that the float trajectory formed distinct elliptical-shapes, exhibiting a new picture of deep clockwise circulation of the float parking depth at 1000 m. On seasonal scale, large fluctuation of properties, mixed-layer depth, and thermocline thickness, were associated with seasonal alternating Ekman upwelling and downwelling dynamics. Upwelling "colder" event (July-September) was characterized by outcrops of 27°C isotherm, 34 psu isohaline and 22 kg/m3 isopycnal at sea surface and large lateral variation of salinity in the upper 50 m. In contrast, these properties lines deepen down to about 100 m depth during downwelling "warmer" event (December-February). Amplitude of seasonal temperature change in the upper-layer was about 3°C. The very fresh water episode in the upper-layer was found during the monsoon break in April.