Further studies of plankton ecosystems in the eastern Indian Ocean. VIII. Seasonal, diurnal, and latitudinal variations in abundance of Euthecosomata along the 110°E. meridian

1977 ◽  
Vol 28 (5) ◽  
pp. 663 ◽  
Author(s):  
M Sakthivel
Keyword(s):  
Indian Ocean ◽  
Water Mass ◽  
Eastern Indian Ocean ◽  
The South ◽  
Subtropical Water ◽  
Maximum Abundance ◽  
Tropical Water ◽  
Nocturnal Increase ◽  
Latitudinal Variations ◽  
Peak Abundance

A number of tropical euthecosomes reached peak abundance in the northern tropical water mass between 9 and 20� s. during the south-east monsoon (May-September), with the maximum abundance north of 14� N. Creseis virgula, Hyalocylis striata, Diacria quadridentata and Cavolinia longirostris were typical of this water mass. A few species such as Limacina lesueuri, Styliola subula, Cuvierina columnella and Cavolinia inflexa reached their maximum abundance at other times of the year in the subtropical water mass (south of 20�S.). Limacina bulimoides was at a maximum around 14�S. during September-November and there was a second maximum around 23�S. (in different months). Nocturnal increase in occurrence and abundance was observed in Limacina leseuri, L. helicina rangii, Clio pyramidata, C.p. lanceolata, Styliola subula, Cuvierina columnella, Diacria quadridentata and Cavolinia inflexa.

Further studies of plankton ecosystems in the eastern Indian Ocean. VI. Ecology of the Euphausiacea

1977 ◽  
Vol 28 (5) ◽  
pp. 627 ◽  
Author(s):  
PS McWilliam
Keyword(s):  
Indian Ocean ◽  
Food Resources ◽  
Water Masses ◽  
Eastern Indian Ocean ◽  
Subtropical Water ◽  
Larvae And Juveniles ◽  
Larval Distribution ◽  
Living Species ◽  
Breeding Condition

Examination of 26 427 euphausiids from 175 samples taken by vertical hauls in the upper 200-m stratum along the 110°E. meridian during 1962-63 indicated that day samples contained mainly larvae and juveniles whereas night samples contained more adults. The following six species of small euphausiids were the most abundant and ubiquitous: Euphausia mutica, E. tenera, E. brevis, Stylocheiron carinatum, S. suhmii, and S. Affine. Their distribution overlapped according to the distribution, in the upper 150 m, of the tropical and subtropical water masses and their mixtures. These species were commonly observed in breeding condition. Their larval distribution was related to the distribution of the breeding adults. The rarer and less ubiquitous species, which were mainly younger stages and deeper living species, showed more pronounced relationships with seasonal water movements. Food resources appeared more important than temperature and salinity in influencing distribution, abundance, and association of species.

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.

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

Distribution and Dispersal of the Phyllosoma Larvae of the Western rock Lobster, Panulirus cygnus, in the South-eastern Indian Ocean

1979 ◽  
Vol 30 (6) ◽  
pp. 773 ◽  
Author(s):  
BF Phillips ◽  
PA Brown ◽  
DW Rimmer ◽  
DD Reid
Keyword(s):  
Indian Ocean ◽  
Continental Shelf ◽  
Average Length ◽  
Eastern Indian Ocean ◽  
Rock Lobster ◽  
The South ◽  
South Eastern ◽  
Phyllosoma Larvae ◽  
Panulirus Cygnus ◽  
One Year

Data on the phyllosoma larvae of P. cygnus caught on seven cruises carried out between April 1976 and January 1977 off the west coast of Australia are presented and discussed. The studies were undertaken to determine the length of the plankton cycle, the distribution of the phyllosoma in the south-eastern Indian Ocean and the extent of the offshore dispersal. Analyses showed the average length of the planktonic life to be less than one year and probably between 9 and 11 months. After hatching most early phyllosoma were transported offshore. Few larvae remained on or near the continental shelf. The maximum westward extent of the phyllosoma distribution of P. cygnus was not determined because significant numbers of phyllosoma were still found as far offshore as 99� 001E. (1500 km offshore), the furthest station sampled. The phyllosoma were distributed over an extensive area of the south-eastern Indian Ocean, and there were few stations beyond the continental shelf between 24� 30'S. and 35� 00'S., from 99� 00'E. to 115� 00'E., during midwinter, at which phyllosoma were not caught. The highest densities of mid-and late-stage phyllosoma occurred between 111� 00' E. and 104� 00' E. (between 375 and 1030 km offshore), at 29� 30'S. The area of greatest abundance was due west of the approximate centre of the adult distribution on the coast. The significance of the circulation of the south-eastern Indian Ocean in the transport of the larvae is discussed.

Observations of warming on the Western Australian continental shelf

2007 ◽  
Vol 58 (10) ◽  
pp. 914 ◽  
Author(s):  
Alan Pearce ◽  
Ming Feng
Keyword(s):  
Indian Ocean ◽  
Continental Shelf ◽  
Southern Oscillation ◽  
Warming Trend ◽  
Eastern Indian Ocean ◽  
The South ◽  
Leeuwin Current ◽  
South Eastern ◽  
The Past ◽  
Western Australian

Global temperature datasets indicate a warming trend in the south-eastern Indian Ocean of ~0.02°C year–1. This is supported by in situ temperature measurements at a coastal monitoring station on the Western Australian continental shelf that have shown a mean temperature rise of 0.013°C year–1 since 1951, corresponding to ~0.6°C over the past 5 decades. Measurements from three other shallow stations between 1985 and 2004 indicated warming trends of 0.026–0.034°C year–1. It is suggested that enhanced air–sea heat flux into the south-eastern Indian Ocean may be a key factor in the rising temperature trend. There has also been a steady rise in salinity over the past half-century. At interannual scales, coherent temperature variability at the various stations indicates that larger-scale processes are influencing the shelf waters and are linked with El Niño/Southern Oscillation (ENSO)-related events in coastal sea level and hence the Leeuwin Current.

Sign in / Sign up

Export Citation Format

Share Document