scholarly journals Influence of 2019 strong positive IOD on the upwelling variability along the southern coast of Java

2021 ◽  
Vol 919 (1) ◽  
pp. 012027
Author(s):  
N Safinatunnajah ◽  
A Wirasatriya ◽  
A Rifai ◽  
Kunarso ◽  
H Setiyono ◽  
...  
Keyword(s):  
Wind Speed ◽  
Indian Ocean ◽  
Climate Variability ◽  
Chlorophyll A ◽  
Coastal Upwelling ◽  
Southern Oscillation ◽  
Propagation Speed ◽  
Southern Coast ◽  
Kelvin Wave ◽  
Easterly Wind

Abstract The seas along the Southern Coast of Java, which are parts of the Indian Ocean, are exposed to climate variability conditions that influence the dynamic of oceanographic parameters in these areas. In terms of interannual climate variability, previous studies showed that Indian Ocean Dipole (IOD) variability is more influential than El Niño Southern Oscillation on the upwelling variability along the Southern Coast of Java. This study aimed to determine the effect of strong positive IOD in 2019 on the upwelling along the Southern coast of Java and investigate the possible mechanisms. This study used sea surface temperature data from OISST, wind speed data from the ASCAT satellite, chlorophyll-a data from the Aqua-MODIS, and sea level anomaly data obtained from altimetry satellites. All data were processed using the composite method. The results show enhanced southeast monsoon upwelling during the 2019 strong positive IOD along the Southern Coast of Java as denoted by higher positive (negative) anomaly of chlorophyll-a (SST) from the climatology. Interestingly, the easterly wind speed is lower than the climatology. Since the IOD influences upwelling along the Southern Coast of Java through the propagation of Kelvin wave, our results indicate the enhancing (weakening) upwelling (downwelling) Kelvin wave during the strong positive IOD in 2019 with the propagation speed of about 1.16 m/s. This Kelvin Wave propagation may amplify the coastal upwelling along the Southern Coast of Java.

scholarly journals SURFACE CHLOROPHYLL-A VARIATIONS ALONG THE SOUTHERN COAST OF JAVA DURING TWO CONTRASTING INDIAN OCEAN DIPOLE EVENTS: 2015 AND 2016

2021 ◽  
Vol 16 (3) ◽  
pp. 116-127
Author(s):  
NETTY KURNIAWATI ◽  
◽  
QURNIA WULAN SARI ◽  
RIZA YULIRATNO SETIAWAN ◽  
EKO SISWANTO ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Chlorophyll A ◽  
Indian Ocean Dipole ◽  
Southern Coast

Modulation of ENSO on Fast and Slow MJO Modes during Boreal Winter

2019 ◽  
Vol 32 (21) ◽  
pp. 7483-7506 ◽  
Author(s):  
Yuntao Wei ◽  
Hong-Li Ren
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
Boreal Winter ◽  
Kelvin Wave ◽  
Wind Anomaly ◽  
Easterly Wind ◽  
Budget Analysis ◽  
La Nina

Abstract This study investigates modulation of El Niño–Southern Oscillation (ENSO) on the Madden–Julian oscillation (MJO) propagation during boreal winter. Results show that the spatiotemporal evolution of MJO manifests as a fast equatorially symmetric propagation from the Indian Ocean to the equatorial western Pacific (EWP) during El Niño, whereas the MJO during La Niña is very slow and tends to frequently “detour” via the southern Maritime Continent (MC). The westward group velocity of the MJO is also more significant during El Niño. Based on the dynamics-oriented diagnostics, it is found that, during El Niño, the much stronger leading suppressed convection over the EWP excites a significant front Walker cell, which further triggers a larger Kelvin wave easterly wind anomaly and premoistening and heating effects to the east. However, the equatorial Rossby wave to the west tends to decouple with the MJO convection. Both effects can result in fast MJO propagation. The opposite holds during La Niña. A column-integrated moisture budget analysis reveals that the sea surface temperature anomaly driving both the eastward and equatorward gradients of the low-frequency moisture anomaly during El Niño, as opposed to the westward and poleward gradients during La Niña, induces moist advection over the equatorial eastern MC–EWP region due to the intraseasonal wind anomaly and therefore enhances the zonal asymmetry of the moisture tendency, supporting fast propagation. The role of nonlinear advection by synoptic-scale Kelvin waves is also nonnegligible in distinguishing fast and slow MJO modes. This study emphasizes the crucial roles of dynamical wave feedback and moisture–convection feedback in modulating the MJO propagation by ENSO.

scholarly journals High Chlorophyll-a Areas along the Western Coast of South Sulawesi-Indonesia during the Rainy Season Revealed by Satellite Data

2021 ◽  
Vol 13 (23) ◽  
pp. 4833
Author(s):  
Anindya Wirasatriya ◽  
Raden Dwi Susanto ◽  
Joga Dharma Setiawan ◽  
Fatwa Ramdani ◽  
Iskhaq Iskandar ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Primary Productivity ◽  
Rainy Season ◽  
Surface Wind ◽  
Western Coast ◽  
Southern Coast ◽  
Easterly Wind ◽  
Chl A ◽  
South Sulawesi ◽  
Upwelling Area

The southern coast of South Sulawesi-Indonesia is known as an upwelling area occurring during dry season, which peaks in August. This upwelling area is indicated by high chlorophyll-a (Chl-a) concentrations due to a strong easterly wind-induced upwelling. However, the investigation of Chl-a variability is less studied along the western coast of South Sulawesi. By taking advantages of remote sensing data of Chl-a, sea surface temperature, surface wind, and precipitation, the present study firstly shows that along the western coast of South Sulawesi, there are two areas, which have high primary productivity occurring during the rainy season. The first area is at 119.0° E–119.5° E; 3.5° S–4.0° S, while the second area is at 119.0° E–119.5° E; 3.5° S–4.0° S. The maximum primary productivity in the first (second) area occurs in April (January). The generating mechanism of the high primary productivity along the western coast of South Sulawesi is different from its southern coast. The presence of river runoff in these two areas may bring anthropogenic organic compounds during the peak of rainy season, resulting in increased Chl-a concentration.

scholarly journals Upwelling di Laut Banda dan Pesisir Selatan Jawa serta Hubungannya dengan ENSO dan IOD

Omni-Akuatika ◽  
2016 ◽  
Vol 12 (3) ◽  
Author(s):  
Herlina Ika Ratnawati ◽  
Rahmat Hidayat ◽  
Ahmad Bey ◽  
Tania June
Keyword(s):  
Chlorophyll A ◽  
Partial Correlation ◽  
Coastal Upwelling ◽  
Ekman Transport ◽  
Ekman Pumping ◽  
Southern Coast ◽  
Partial Correlation Analysis ◽  
June July August ◽  
June July ◽  
Equal Contribution

Upwelling events analysis in southern coast of Java and Banda sea were conducted. The events were identified by using satellite data i.e. wind surface, Sea Surface Temperature (SST) and ocean color during period of 14 years (2002-2016) which calculated by Ekman pumping and Ekman transport. It’s found that Ekman pumping velocity in Banda Sea reached a maximum in June-July-August (JJA) by approximately 3,65x10 -6 . Comparing with Ekman transport, Ekman pumping makes an even greater contribution to the local upwelling in Banda Sea. Ekman pumping velocity in southern coast of Java reached a maximum in June-July-August (JJA) by approximately 4,9x10 -1 ms . Ekman pumping and Ekman transport makes an equal contribution to coastal upwelling in southern coast of Java. That’s related to highest clorophyll-a concentration apperars in JJA periode. Partial correlation analysis then was applied to identify a correlation between chlorophyll-a concentration and interannual climate variabilities such as ENSO and IOD. Partial Correlation between chlorophyll-a and Nino 3.4 and DMI-Dipole Mode Index (controlled) in Banda Sea is 0.18, and 0.05 in southercoast of Java. It’s represent ENSO (Elnino Southern Oscilation) has higher influences to Banda Sea than southern coast of Java. Partial correlation between chlorophyll-a and DMI and Nino 3.4 (controlled) is 0.55 in southern coast of Java, and 0.25 in Banda Sea. Its represent IOD (Indian Ocean Dipole) has higher influences to southern coast of Java than Banda Sea. Upwelling in Banda sea and along southern coast of Java dominantly occurs in southeast monsoon as a responds to regional wind driven motion associated with the monsoon climate. Various condition of chlorophyll-a booming also occured according to combination of ENSO and IOD events. -6 -1 msKeywords: upwelling, Banda sea, southern coast of Java, Ekman transport, Ekman pumping, IOD, ENSO 

scholarly journals Indian Ocean Variability in the CMIP5 Multimodel Ensemble: The Basin Mode

2013 ◽  
Vol 26 (18) ◽  
pp. 7240-7266 ◽  
Author(s):  
Yan Du ◽  
Shang-Ping Xie ◽  
Ya-Li Yang ◽  
Xiao-Tong Zheng ◽  
Lin Liu ◽  
...  
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Tropical Indian Ocean ◽  
Ocean Basin ◽  
North Indian Ocean ◽  
Cmip5 Models ◽  
Northwest Pacific ◽  
Kelvin Wave

Abstract This study evaluates the simulation of the Indian Ocean Basin (IOB) mode and relevant physical processes in models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). Historical runs from 20 CMIP5 models are available for the analysis. They reproduce the IOB mode and its close relationship to El Niño–Southern Oscillation (ENSO). Half of the models capture key IOB processes: a downwelling oceanic Rossby wave in the southern tropical Indian Ocean (TIO) precedes the IOB development in boreal fall and triggers an antisymmetric wind anomaly pattern across the equator in the following spring. The anomalous wind pattern induces a second warming in the north Indian Ocean (NIO) through summer and sustains anticyclonic wind anomalies in the northwest Pacific by radiating a warm tropospheric Kelvin wave. The second warming in the NIO is indicative of ocean–atmosphere interaction in the interior TIO. More than half of the models display a double peak in NIO warming, as observed following El Niño, while the rest show only one winter peak. The intermodel diversity in the characteristics of the IOB mode seems related to the thermocline adjustment in the south TIO to ENSO-induced wind variations. Almost all the models show multidecadal variations in IOB variance, possibly modulated by ENSO.

scholarly journals Seasonal coastal upwelling in the Bali Strait: a model study

2021 ◽  
Vol 944 (1) ◽  
pp. 012055
Author(s):  
A Suprianto ◽  
A S Atmadipoera ◽  
J Lumban-Gaol
Keyword(s):  
Chlorophyll A ◽  
Coastal Upwelling ◽  
Fish Distribution ◽  
Sea Surface ◽  
Monsoon Period ◽  
Easterly Wind ◽  
Chl A ◽  
Model Study ◽  
Velocity Surface ◽  
Upwelling Event

Abstract Bali Strait is part of fisheries management zone (WPP 573), where abundant fishery potential, of lemuru fish commodity. Here, physical oceanographic setting such as upwelling event plays an important role on maintaining high primary productivity and lemuru fish distribution. This study aims to describe physical process and dynamics of seasonal coastal upwelling using time-series datasets (2008 and 2014) of temperature, salinity, current velocity, surface chlorophyll-a (chl-a) from INDESO model and satellite imagery. The results showed that upwelling in the Bali Strait only during the southeast monsoon period when the south-easterly wind force surface Ekman drift of about 5.5 × 10−3 Sv flowing south-eastward (toward offshore). Upwelling event is characterized by minimum parameter of sea surface temperature (24.93 °C), and sea level anomaly (0.75 m), but maximum of surface chlorophyll-a (1.33 mg/m3). Furthermore, isotherm of 26 °C and Isohaline 33.7 psu are outcropped at sea surface in the center of upwelling zone. In contrast, during the nortwest monsoon period these isolines remain at deeper layer of about 80-90 m depth. Mean temperature-based upwelling index during peak of upwelling in August (1.19±0.19 °C). Upwelling impact on high abundance of lemuru fish (Sardinella sp.) production two month later after peak of chl-a.

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

2020 ◽  
Vol 52 (1) ◽  
pp. 105
Author(s):  
Eko Supriyadi ◽  
Rahmat Hidayat
Keyword(s):  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Coastal Upwelling ◽  
Southern Oscillation ◽  
High Standard ◽  
Sea Surface ◽  
Temporal And Spatial Distribution ◽  
Chl A ◽  
Upwelling Area

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. 

scholarly journals Impact of the April–May SAM on Central Pacific Ocean sea temperature over the following three seasons

2021 ◽  
Author(s):  
Ting Liu ◽  
Jianping Li ◽  
Cheng Sun ◽  
Tao Lian ◽  
Yazhou Zhang
Keyword(s):  
Indian Ocean ◽  
Cold Water ◽  
Southern Oscillation ◽  
Equatorial Pacific ◽  
Boreal Winter ◽  
Central Pacific ◽  
Sea Temperature ◽  
Easterly Wind ◽  
The Indian Ocean ◽  
The Impact

AbstractAlthough the impact of the extratropical Pacific signal on the El Niño–Southern Oscillation has attracted increasing concern, the impact of Southern Hemisphere Annular Mode (SAM)-related signals from outside the southern Pacific Basin on the equatorial sea temperature has received less attention. This study explores the lead correlation between the April–May (AM) SAM and central tropical Pacific sea temperature variability over the following three seasons. For the positive AM SAM case, the related simultaneous warm SST anomalies in the southeastern Indian Ocean favor significant regulation of vertical circulation in the Indian Ocean with anomalous ascending motion in the tropics. This can further enhance convection over the Marine Continent, which induces a significant horizontal Kelvin response and regulates the vertical Walker circulation. These two processes both result in the anomalous easterlies east of 130° E in the equatorial Pacific during AM. These easterly anomalies favor oceanic upwelling and eastward propagation of the cold water into the central Pacific. The cold water in turn amplifies the development of the easterly wind and further maintains the cold water into the boreal winter. The results presented here not only provide a possible link between extratropical climate variability in the Indian Ocean and climate variation in the equatorial Pacific, but also shed new light on the short-term prediction of tropical central Pacific sea temperature.

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