NOPR Collection:

Physical characteristics of the Laccadive Sea (Lakshadweep)

2016-12-27T10:39:55Z

Title: Physical characteristics of the Laccadive Sea (Lakshadweep) Authors: Varkey, M J; Das, V Kesava; Raju, D V Rama Abstract: Several physical properties of the Laccadive Sea were studied based on data collected in March/April and the results compared with the data earlier obtained from the same are during October and December. The mixed layer extended to 90-100 m depth with a 2-layered structure, an upper isothermal and a lower with weak thermal gradients. The Arabian Sea High salinity water was observed as a sub-surface high salinity core in the Laccadive Sea. Persian Gulf and Red Sea waters were also observed. Surface salinity showed wide variations which were related to the influx of water from the Bay of Bengal. Considerable meridional salinity gradients existed at the surface. Page(s): 203-210

Wave characteristics of the Laccadive Sea (Lakshadweep)

2016-12-27T10:38:42Z

Title: Wave characteristics of the Laccadive Sea (Lakshadweep) Authors: Das, V Kesava; Varkey, M J; Raju, D V Rama Abstract: Waves in the Laccadive Sea were recorded during March-April 1978 (31st of R V Gaveshani) using a ship-borne wave recorder. Zero-crossing period, significant wave height and spectral width parameter were determined and their distributions studied. Predominant significant wave height and zero-crossing period were 50 to 70 cm and 8 to 8.5 sec respectively. Seasonal variations in the wave characteristics for the area were also studied using the historical data reported by the ships. The predominant wave periods and wave heights were 5-6 sec and 0.5 to 1.5 m respectively during the fair weather season (October-May) and 5-9 sec and 1-3 m respectively during the rough weather season (June-September). A wide range of wave heights 0.5-5 m occurred during the rough season. Page(s): 211-214

Chemical oceanography of the Arabian Sea: Part IV Laccadive Sea

2016-12-27T10:36:55Z

Title: Chemical oceanography of the Arabian Sea: Part IV Laccadive Sea Authors: Gupta, R Sen; Moraes, Caroline; Kureishy, T W; Yanan, V N Sankaranara; Jana, T K; Naqvi, S W A; Rajagopal, M D Abstract: Data collected during the 10the (October 1976) and 31st (March-April 1978) cruises of R V Gaveshani suggest that water movements, considered typical of island-arc regions, are responsible for high levels of productivity observed in the Laccadive Sea. Patterns of distribution of nutrients and nutrients-oxygen relationships are similar to those observed in other parts of the Arabian Sea. High magnesium and low fluoride concentrations in the water indicate probable loss of the latter as insoluble ion-pairs and as apatites. Page(s): 215-221

Biological characteristics of the Laccadive Sea (Lakshadweep)

2016-12-27T10:34:00Z

Title: Biological characteristics of the Laccadive Sea (Lakshadweep) Authors: Bhattathiri, P M A; Devassy, V P Abstract: Primary productivity, chlorophyll a, phaeopigments and particulate organic carbon were studied in the Laccadive Sea during March-April 1978. Column primary productivity, chlorophyll a and phaeopigments ranged from 254 to 830 mg C/m² day (av. 372), 1.4 to 15.4 mg/m² (av. 4.9) and 1.16 to 17.2 mg/m² (av. 4.6) respectively. Pigments from nannoplankton were 22 to 100% of the total phytoplankton pigments. Particulate organic carbon values ranged from 1.55 to 6.16 g/m² (av. 3.61). Trichodesmium erythraeum and T. thiebautii were present at all the stations. Gymnodinium sp. was mostly present near the islands. Attenuation coefficient varied from 0.061 to 0.113. On an average the detrital carbon was 81% of the particulate organic carbon. Page(s): 222-226