CHARACTERISTIC OF PHYSICAL OCEANOGRAPHY IN EAST INDIAN OCEAN DURING POSITIVE PHASE OF INDIAN OCEAN DIPOLE (IOD) OF 1994/1995, 1997/1998, AND 2006/2007

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Pramudyo Dipo ◽  
I Wayan Nurjaya ◽  
Fadli Syamsudin
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Dipole ◽  
Eastern Indian Ocean ◽  
Comparative Characteristic ◽  
Physical Oceanography ◽  
The South ◽  
Bipolar Structure ◽  
Maturation Phase ◽  
The Difference ◽  
Formation Phase

There is an inter-annual phenomenon in the Indian Ocean that occurs because of the interaction between atmosphere and ocean are known Indian Ocean Dipole (IOD). IOD is a bipolar structure that characterized by the difference of sea surface temperature to normal. The objectives of this study is to know the characteristic of physical oceanography in the eastern part of Indian Ocean during the formation phase, maturation phase and decay phases of positive IOD. The second objective was to determine the comparative characteristic of physical oceanography in the eastern Indian Ocean between the positive IOD in different years. The strengthening of the South Equatorial Current in transitional seasons I (March-May) followed by early cooling of the SST which is indicated by the formation phase of IOD. At the Southeast monsoon (June to August) and the beginning of the season transition II, there is a visible presence of upwelling in the south of Java, which is then further extends to the peak in September (maturation phase) and begin to disappear in October followed by warming of the SST on the East of Indian Ocean in November (decay phase).Keywords: Indian Ocean Dipole, upwelling, Empirical Orthogonal Function (EOF) analysis, Eastern Indian Ocean

scholarly journals CHARACTERISTIC OF PHYSICAL OCEANOGRAPHY IN EAST INDIAN OCEAN DURING POSITIVE PHASE OF INDIAN OCEAN DIPOLE (IOD) OF 1994/1995, 1997/1998, AND 2006/2007

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Pramudyo Dipo ◽  
I Wayan Nurjaya ◽  
Fadli Syamsudin
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Dipole ◽  
Eastern Indian Ocean ◽  
Comparative Characteristic ◽  
Physical Oceanography ◽  
The South ◽  
Bipolar Structure ◽  
Maturation Phase ◽  
The Difference ◽  
Formation Phase

<p>There is an inter-annual phenomenon in the Indian Ocean that occurs because of the interaction between atmosphere and ocean are known Indian Ocean Dipole (IOD). IOD is a bipolar structure that characterized by the difference of sea surface temperature to normal. The objectives of this study is to know the characteristic of physical oceanography in the eastern part of Indian Ocean during the formation phase, maturation phase and decay phases of positive IOD. The second objective was to determine the comparative characteristic of physical oceanography in the eastern Indian Ocean between the positive IOD in different years. The strengthening of the South Equatorial Current in transitional seasons I (March-May) followed by early cooling of the SST which is indicated by the formation phase of IOD. At the Southeast monsoon (June to August) and the beginning of the season transition II, there is a visible presence of upwelling in the south of Java, which is then further extends to the peak in September (maturation phase) and begin to disappear in October followed by warming of the SST on the East of Indian Ocean in November (decay phase).</p><p>Keywords: Indian Ocean Dipole, upwelling, Empirical Orthogonal Function (EOF) analysis, Eastern Indian Ocean</p>

scholarly journals Impact of the Strong Downwelling (Upwelling) on Small Pelagic Fish Production during the 2016 (2019) Negative (Positive) Indian Ocean Dipole Events in the Eastern Indian Ocean off Java

Climate ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 29
Author(s):  
Jonson Lumban-Gaol ◽  
Eko Siswanto ◽  
Kedarnath Mahapatra ◽  
Nyoman Metta Nyanakumara Natih ◽  
I Wayan Nurjaya ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Dipole ◽  
Pelagic Fish ◽  
Eastern Indian Ocean ◽  
Fish Production ◽  
Small Pelagic Fish ◽  
Field Surveys ◽  
Chl A ◽  
Positive Indian Ocean Dipole ◽  
The Impact

Although researchers have investigated the impact of Indian Ocean Dipole (IOD) phases on human lives, only a few have examined such impacts on fisheries. In this study, we analyzed the influence of negative (positive) IOD phases on chlorophyll a (Chl-a) concentrations as an indicator of phytoplankton biomass and small pelagic fish production in the eastern Indian Ocean (EIO) off Java. We also conducted field surveys in the EIO off Palabuhanratu Bay at the peak (October) and the end (December) of the 2019 positive IOD phase. Our findings show that the Chl-a concentration had a strong and robust association with the 2016 (2019) negative (positive) IOD phases. The negative (positive) anomalous Chl-a concentration in the EIO off Java associated with the negative (positive) IOD phase induced strong downwelling (upwelling), leading to the preponderant decrease (increase) in small pelagic fish production in the EIO off Java.

scholarly journals Molecular and spatial distributions of dicarboxylic acids, oxocarboxylic acids, and <i>α</i>-dicarbonyls in marine aerosols from the South China Sea to the eastern Indian Ocean

2020 ◽  
Vol 20 (11) ◽  
pp. 6841-6860 ◽  
Author(s):  
Jing Yang ◽  
Wanyu Zhao ◽  
Lianfang Wei ◽  
Qiang Zhang ◽  
Yue Zhao ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Indian Ocean ◽  
South China Sea ◽  
South China ◽  
The South China Sea ◽  
Photochemical Oxidation ◽  
Eastern Indian Ocean ◽  
The South ◽  
China Sea ◽  
Mass Ratios

Abstract. Marine aerosol samples collected from the South China Sea (SCS) to the eastern Indian Ocean (EIO) during a cruise from 10 March to 26 April 2015 were studied for diacids and related compounds. In view of air mass backward trajectories, source regions, and geographical features, the cruise area was categorized into the South China Sea (SCS), the eastern Indian Ocean off the coast of western Indonesia (EIO-WI), the EIO off the coast of Sri Lanka (EIO-SL), Malacca, and the Sri Lanka docking point (SLDP). Total concentrations of diacids, oxoacids, and α-dicarbonyls were high at the SLDP, followed by the SCS and Malacca, and they were the low in the EIO-WI. In this study, oxalic acid (C2) was the dominant diacid during the cruise, followed by malonic acid (C3) in the SCS, EIO-WI, EIO-SL, and Malacca, and succinic acid (C4) was relatively more abundant than C3 diacid at the SLDP. Except for SLDP, C3∕C4 mass ratios were always greater than 1, and no significant difference was observed during the cruise. The C2∕C4 and C2∕total diacid ratios also showed similar trends. The average mass ratios of adipic acid (C6) to azelaic acid (C9) were less than unity except for in the EIO-WI; the mass ratios of phthalic acid (Ph) to azelaic acid (C9) were less than 2 except for in the SCS. The concentrations of diacids were higher when the air masses originated from terrestrial regions than when they originated from remote oceanic regions. Based on the molecular distributions of organic acids, the mass ratios, and the linear correlations of selected compounds in each area, we found that the oxidation of biogenic volatile organic compounds (BVOCs) released from the ocean surface and subsequent in situ photochemical oxidation was the main contributor to diacids, oxocarboxylic acids, and α-dicarbonyls from the SCS to the EIO. In addition, the continental outflow, which is enriched in anthropogenic VOCs and their aged products, influenced the organic aerosol loading, particularly over the SCS. Emissions from Sri Lanka terrestrial vegetation as well as fossil fuel combustion and subsequent photochemical oxidation also played a prominent role in controlling the organic aerosol loading and the molecular distribution of diacids and related compounds at the SLDP.

scholarly journals Satellite and Argo Observed Surface Salinity Variations in the Tropical Indian Ocean and Their Association with the Indian Ocean Dipole Mode

2015 ◽  
Vol 28 (2) ◽  
pp. 695-713 ◽  
Author(s):  
Yan Du ◽  
Yuhong Zhang
Keyword(s):  
Indian Ocean ◽  
Ocean Circulation ◽  
Indian Ocean Dipole ◽  
Coastal Upwelling ◽  
Tropical Indian Ocean ◽  
Sea Surface Salinity ◽  
The South ◽  
Surface Salinity ◽  
Indian Ocean Dipole Mode ◽  
The Indian Ocean

Abstract This study investigates sea surface salinity (SSS) variations in the tropical Indian Ocean (IO) using the Aquarius/Satelite de Aplicaciones Cientificas-D (SAC-D) and the Soil Moisture and Ocean Salinity (SMOS) satellite data and the Argo observations during July 2010–July 2014. Compared to the Argo observations, the satellite datasets generally provide SSS maps with higher space–time resolution, particularly in the regions where Argo floats are sparse. Both Aquarius and SMOS well captured the SSS variations associated with the Indian Ocean dipole (IOD) mode. Significant SSS changes occurred in the central equatorial IO, along the Java–Sumatra coast, and south of the equatorial IO, due to ocean circulation variations. During the negative IOD events in 2010, 2013, and 2014, westerly wind anomalies strengthened along the equator, weakening coastal upwelling off Java and Sumatra and decreasing SSS. South of the equatorial IO, an anomalous cyclonic gyre changed the tropical circulation, which favored the eastward high-salinity tongue along the equator and the westward low-saline tongue in the south. An upwelling Rossby wave favored the increase of SSS farther to the south. During the positive IOD events in 2011 and 2012, the above-mentioned processes reversed, although the decrease of SSS was weaker in magnitude.

Dynamics of 2015 positive Indian Ocean Dipole

2019 ◽  
Vol 69 (1) ◽  
pp. 75
Author(s):  
Putri Adia Utari ◽  
Mokhamad Yusup Nur Khakim ◽  
Dedi Setiabudidaya ◽  
Iskhaq Iskandar
Keyword(s):  
Heat Flux ◽  
Indian Ocean ◽  
Indian Ocean Dipole ◽  
Tropical Indian Ocean ◽  
Boreal Summer ◽  
The South ◽  
South Eastern ◽  
Positive Indian Ocean Dipole ◽  
Sst Warming ◽  
Dipole Pattern

Evolution of typical positive Indian Ocean Dipole (pIOD) event was dominated by a significant sea-surface temperature (SST) cooling in the south-eastern tropical Indian Ocean. Interestingly, during the evolution of 2015 pIOD event, the SST in the south-eastern tropical Indian Ocean did not reveal significant cooling, instead anomalous strong SST warming took place in the western tropical Indian Ocean off the East African coast. This anomalous SST warming was associated with a weakening of the Asian summer monsoon. Furthermore, analysis on the mixed layer heat budget demonstrated that the evolution of the 2015 pIOD event could be attributed mainly to the air-sea heat flux. By decomposing the air-sea heat flux, it is found that reduced latent heat loss plays an important role on the SST warming in the western pole and keeping SST warm in the eastern pole. We note that a residual term also may play a role during the initial development of the event. In contrast to the SST pattern, the subsurface temperature revealed a clear positive dipole pattern. Shallow (deep) 20°C isothermal layer in the eastern (western) equatorial Indian Ocean was observed during boreal summer. This robust subsurface dipole pattern indicated that the subsurface ocean response was largely wind driven through the equatorial wave dynamics as previously suggested.

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