Influence of Coastal Upwelling on SST Trends along the South Coast of Java

Varela, R.; Santos, F.; Gómez‐Gesteira, M.; Álvarez, I.; Costoya, X.; Dias, João Miguel

doi:10.1371/journal.pone.0162122

Cited by 29 publications

(30 citation statements)

References 38 publications

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“…In addition, a long-term trend in the upwelling strength is studied recently. For example, Varela et al (2016) suggest the weakening of the upwelling although the SST shows a cooling trend due to cooler subsurface temperature. Sources of this upwelled water mass are not clearly determined yet.…”

Section: Sumatra and Javamentioning

confidence: 99%

“…Sources of this upwelled water mass are not clearly determined yet. A study using a numerical model proposes the Indonesian throughflow as a possible source for the upwelling water off the Java coast (Valsala and Maksyutov, 2010), while another study suggests that water mass from the northwest via South Java Current could be upwelled in this region (Varela et al, 2016). As in the other EBUS, high biological productivity is expected in the Sumatra-Java upwelling region during boreal summer and fall (Wei et al, 2012), with high nutrient and chlorophyll-a concentrations along the coasts (e.g.…”

Section: Sumatra and Javamentioning

confidence: 99%

See 1 more Smart Citation

Reviews and syntheses: Physical and biogeochemical processes associated with upwelling in the Indian Ocean

Vinayachandran¹,

Masumoto²,

Roberts³

et al. 2021

Preprint

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Abstract. The Indian Ocean presents two distinct climate regimes. The North Indian Ocean is dominated by the monsoons, whereas the seasonal variation is less pronounced in the south. The prevailing wind pattern produces upwelling along different parts of the coast in both hemispheres during different times of the year. Additionally, dynamical processes and eddies either cause or enhance upwelling. This paper reviews the phenomena of upwelling along the coast of the Indian Ocean extending from the tip of South Africa to the southern tip of the west coast of Australia. Observed features, underlying mechanisms, and the impact of upwelling on the ecosystem are presented. In the Agulhas Current region, cyclonic eddies associated with the Natal pulses drive slope upwelling and enhances chlorophyll concentration along the continental margin. The Durban break-away eddy spun-up by the Agulhas upwells cold nutrient-rich water. Besides, topographically induced upwelling occurs along the inshore edges of Agulhas Current. Wind-driven coastal upwelling occurs along the South coast of Africa and augments the dynamical upwelling in the Agulhas Current. Upwelling hotspots along Mozambique are present in the northern and southern sectors of the channel, and they are ascribed to dynamical effects of ocean circulation in addition to wind forcing. Interaction of mesoscale eddies with the western boundary, anticyclonic eddy pair interactions, and passage of cyclonic eddies cause upwelling. Upwelling along the southern coast of Madagascar is caused by Ekman wind-driven mechanism and by eddy generation and inhibited by Southwest Madagascar Coastal Current. The seasonal upwelling that occurs along the East African coast is primarily driven by the Northeast monsoon winds and enhanced by topographically induced shelf-breaking and shear instability between the East African Coastal Current and the island chains. Somali coast presents a strong case for the classical Ekman type of upwelling. This upwelling can be inhibited by the arrival of deeper thermocline signals generated in the offshore region by wind stress curl. The upwelling is nearly uniform along the coast of Arabia, it is caused by the alongshore component of the summer monsoon winds and modulated by the arrival of Rossby waves generated in the offshore region by cyclonic wind stress curl. Along the west coast of India, upwelling is driven by coastally trapped waves together with the alongshore component of the southwesterlies. Along the southern tip of India and Sri Lanka, the strong Ekman transport dives upwelling. Upwelling is feeble along the east coast of India and occurs during the summer, caused by alongshore winds. In addition, mesoscale eddies lead to upwelling but the arrival of river water plumes inhibits upwelling along this coast. Southeasterly winds drive upwelling along the coast of Sumatra and Java during summer. Kelvin wave propagation originating from the Equatorial Indian Ocean affects the magnitude and extent of Sumatra and Java upwelling. Both ENSO and IOD events cause large variability of upwelling here. Along the west coast of Australia, southerly winds can dominate over the Leeuwin Current, causing sporadic upwelling, which is prominent along the southwest, central, and Gascoyne coasts during summer. The open ocean upwelling in the southern tropical Indian Ocean and within the Sri Lanka Dome is driven primarily by the wind stress curl but also impacted by Rossby wave propagations. Upwelling is a key driver in enhancing biological productivity in all sectors of the coast, as indicated by enhanced sea surface chlorophyll concentrations. Additional knowledge at varying levels has been gained through in situ observations and model simulations. In the Mozambique channel, upwelling simulates new production, and circulation redistributes the production generated by upwelling and mesoscale eddies leading to observations of higher ecosystem impact along the edges of eddies. Similarly, along the southern Madagascar coast, biological connectivity is influenced by the transport of phytoplankton from upwelling zones. Along the coast of Kenya, both productivity rates and zooplankton biomass are higher during the upwelling season. Along the Somali coast, accumulation of upwelled nutrients in the northern part of the coast leads to spatial inhomogeneity in productivity. On the other hand, productivity is more uniform along the coasts of Yemen and Oman. Upwelling along the west coast of India has several biogeochemical implications, including oxygen depletion, denitrification, and high production of CH4 and dimethyl sulfide. Though feeble, wind-driven upwelling leads to significant enhancement of phytoplankton in the northwest Bay of Bengal during the summer monsoon. Along the Sumatra and Java coasts, upwelling affects the phytoplankton composition and assemblages. Dissimilarities in copepod assemblages occur during the upwelling periods along the west coast of Australia. Phytoplankton abundance characterizes inshore edges of the slope during upwelling season, and upwelling eddies are associated with abundance in Krill. The review identifies the northern coast of the Arabian Sea and eastern coasts of the Bay of Bengal as the least observed sectors. Further, sustained long-term observations with high temporal and spatial resolutions along with high-resolution modeling efforts are suggested for a proper description of upwelling, its variability, and its relationship to the ecosystem.

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Section: Sumatra and Javamentioning

confidence: 99%

Section: Sumatra and Javamentioning

confidence: 99%

Reviews and syntheses: Physical and biogeochemical processes associated with upwelling in the Indian Ocean

Vinayachandran¹,

Masumoto²,

Roberts³

et al. 2021

Preprint

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“…Secara umum upwelling bisa diidentifikasi dengan adanya trend penurunan temperatur pada kolom air dari permukaan hingga kedalaman tertentu. Tren penurunan temperatur di selatan Jawa pada periode Juli hingga Oktober terlihat jelas dari permukaan hingga kedalaman 100 m. Kemudian dari kedalaman 100 m hingga kedalaman 200 m trend penurunan temperatur tersebut semakin kecil dan kemudian di kedalaman dibawah 200 m trend penurunan temperatur sudah tidak terlihat lagi (Varela et al, 2016).…”

Section: Pendahuluanunclassified

“…Pada musim timur massa air dingin naik ke permukaan, sedangkan pada musim barat massa air hangat turun ke kedalaman, bahkan pada periode tertentu seperti pada tahun 2014, Naiknya massa air dari lapisan bawah menuju permukaan belum terlihat pada kedalaman 500 m. Perbedaan suhu pada antara musim barat dan musim timur terlihat jelas pada kedalaman 200 m dan 100 m, dimana pada musim timur (Gambar 8.a) suhu di perairan selatan Jawa lebih rendah sekitar 2°C dibandingkan pada musim barat (Gambar 8.b), khususnya di sepanjang pesisir Pulau Jawa hingga sekitar lintang 11°S. Varela et al (2016), menyatakan bahwa penurunan SPL di sepanjang pesisir Jawa menyebar ke arah selatan menuju laut lepas. Terdapat perbedaan SPL yang cukup tinggi antara perairan pesisir dengan perairan di laut lepas di selatan jawa yang berkisar sekitar 2°C dengan SPL yang lebih dingin di dekat pesisir Jawa.…”

Section: Analisis Multilayer Fenomena Upwellingunclassified

Analisis Multilayer Variabilitas Upwelling Di Perairan Selatan Jawa

Sukresno

Jatisworo

Kusuma

2018

Jurnal Kelautan Nasional

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ABSTRAKVariabilitas upwelling di perairan selatan Jawa telah diidentifikasi. Analisis multilayer dilakukan dengan menggunakan data ARGO Float periode 2016 hingga 2017. Variabilitas suhu permukaan laut (SPL) dan klorofil-a (klor-a) dianalisis dengan menggunakan data satelit MODIS Aqua periode 2007 hingga 2017. Pengaruh El Nino Southern Oscillation (ENSO) terhadap upwelling dilakukan dengan menggunakan indeks Oceanic Nino Index (ONI), sedangkan pengaruh Indian Ocean Dipole (IOD) direpresentasikan dengan menggunakan indeks Dipole Mode Index (DMI). Dari hasil penelitian diketahui bahwa ENSO mempengaruhi intensitas upwelling. Pada periode el nino intensitasnya mengalami peningkatan yang diikuti oleh penurunan SPL dan naiknya konsentrasi klor-a, sebaliknya pada periode la nina terjadi penurunan intensitas yang diikuti naiknya SPL dan turunnya konsentrasi klor-a. Peningkatan intensitas juga terdeteksi pada saat terjadi periode IOD positif, sedangkan penurunan intensitas terjadi pada periode IOD negatif. ABSTRACT Upwelling variability in the Indian Ocean South of Java has been identified. Multilayer analysis was performed using ARGO Float data during 2016 -2017. Variability of sea surface temperature (SST) and chlorophyll-a concentration (chlor-a) were analyzed using Aqua MODIS satellite data during 2007 -2017. The influence of El Nino Southern Oscillation (ENSO) on upwelling intensity was conducted using the Oceanic Nino Index (ONI), while the influence of Indian Ocean Dipole (IOD) was represented by using Dipole Mode Index (DMI).Result of the study show that ENSO give high impact on upwelling variability. During el nino period, the intensity has increased, followed by a decrease in SPL and increased in chlor-a concentration, on the other hand during la nina period there is a decrease of intensity followed by an increase in SPL and a decrease in chlor-a concentration. Increased intensity was also detected during a positive IOD period, while decreased intensity was occurred during a negative IOD period.

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“…Besides, the upwelling event is also related to the dynamics of the SST local waters (Napitu et al, 2015;Chen et al, 2015;Varela et al, 2016). e dynamic of SST in the Indian Ocean is directly related to the event of IOD; although it does not rule out the effect of ENSO from the Paci c Ocean, it could affect the physical upwelling process in the Indian Ocean (Chen et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Identification of Upwelling Area of the Western Territorial Waters of Indonesia From 2000 To 2017

Supriyadi¹,

Hidayat²

2020

IJG

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The Western Waters of Indonesian (WWI) present a diverse interaction of ocean-atmosphere dynamics. One of them represents the event of Indian Ocean Dipole (IOD), El Niño–Southern Oscillation (ENSO), and upwelling. The objective of this study is to determine the dynamics of chlorophyll-a concentration (Chl–a), especially during IOD and ENSO. Also, this study is aimed to examine the temporal and spatial distribution of the upwelling area from 2000 to 2017. The data utilized consisted of Chl–a, wind stress, Sea Level Anomaly (SLA), and Sea Surface Temperature (SST). The technique used to determine the upwelling area was by examining the maximum conditions of Chl–a, the low temperature of SST, and SLA. The results showed the sea surface temperature had a relationship with the concentration of Chl–a. It was obtained if the Directional Movement Index (DMI) and N3.4 (Niño 3.4 Index) moved stably (not too fluctuation) resulting in high concentrations of Chl–a. High standard deviations of SST are recognized around the Sunda Strait (June – October). When the standard deviation of SST is high, there is also a tendency for high Chl–a concentrations, while the results of empirical calculations show that large areas of upwelling occurred in January and September respectively at 12,447.72 km2 and 8,146.20 km2. Based on the results of the analysis, it can be concluded that the upwelling does not only occur at the coastal area of Western Sumatra (coastal upwelling), but it also occurs in the eastern territorial waters of the Indian Ocean. In addition, the upwelling area has the same pattern as the Chl–a concentration in January - October.

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Influence of Coastal Upwelling on SST Trends along the South Coast of Java

Cited by 29 publications

References 38 publications

Reviews and syntheses: Physical and biogeochemical processes associated with upwelling in the Indian Ocean

Reviews and syntheses: Physical and biogeochemical processes associated with upwelling in the Indian Ocean

Analisis Multilayer Variabilitas Upwelling Di Perairan Selatan Jawa

Identification of Upwelling Area of the Western Territorial Waters of Indonesia From 2000 To 2017

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