National Institute of Oceanography, India

About: National Institute of Oceanography, India is a facility organization based out in Panjim, Goa, India. It is known for research contribution in the topics: Monsoon & Population. The organization has 4713 authors who have published 6927 publications receiving 174272 citations.

Collapse of the echinoid Paracentrotus lividus populations in the Eastern Mediterranean—result of climate change?

Abstract: The European purple sea urchin (Paracentrotus lividus) is considered to be a key herbivore throughout its distribution range--North-East Atlantic and Mediterranean Sea. It was also abundant in its eastern distributional edge, on rocky habitats of the coastline of Israel, but its populations have recently collapsed, and today it is an extremely rare species in the region. Field and laboratory experiments, that were carried out in order to examine the impact of the recent sea surface temperature rise in the Eastern Mediterranean, showed massive urchin mortality when temperatures crossed 30.5 °C before reaching peak summer values. These results suggest that elevated seawater temperatures in recent years may be a main cause for the disappearance of P. lividus from the southeast Mediterranean Sea, which may indicate distributional range contraction in this region.

Seasonal variability of physico{chemical characteristics of the Haldia channel of Hooghly estuary, India

Abstract: during peak ebb and ∞ood tide conditions irrespective of the season. Longitudinal eddy difiusion coe‐cient (Kx) was estimated as 757m s i1 and 811m 2 s i1 during summer and post-monsoon seasons, respectively. The vertical eddy difiusion coe‐cient ("v) was estimated as 0:0337m 2 s i1 during post-monsoon season. The salinity and current observations are compared with those obtained from models reported earlier. Values of pH, Dissolved Oxygen and Biological Oxygen Demand are within the threshold limits of the estuarine environment. Nutrients show seasonal variation in the estuarine environment. High values (160{2686mg l i1 ) of total suspended matter were noticed both at surface and bottom in the study region showing the impact of fresh water and sediment transportation.

Community structure and seasonal variation of an inshore demersal fish community at Goa, West Coast of India

Abstract: Structure and seasonal variation of an inshore demersal fish assemblage have been described from 52 trawl samples collected between November 1988–November 1989 from Aguada and Marmugao Bays at Goa (west coast of India). A total of 12 519 individuals belonging to 59 species were collected. There was a clear seasonal fluctuation in relative abundance, biomass, species occurrence and species dominance. Families such as Sciaenidae, Leiognathidae, Cynoglossidae, Clupeidae and Ariidae dominated the demersal fish community, both in abundance and in biomass over the two areas. About 50% of the recorded species regularly occurred in the two areas. Density and biomass were high during post- and pre-monsoon seasons and low during the monsoon seasons. The species assemblages at the two sites were similar and showed much overlap of dominant species. Resident and quasi-resident species were dominant throughout the year and the overall population consisted mainly of marine coastal species. Cluster analysis showed species segregation into seasonal groups and intense association among different species groups. There was seasonal fluctuation in diversity indices and a marginal increase in species richness in Aguada bay was noticed. The dominance of juveniles in the catches indicate that the two areas serve as nursery grounds for the juveniles of several commercially important marine teleosts.

Impact of Tropical Cyclones on the Heat Budget of the South Pacific Ocean

Abstract: The present study investigates the integrated ocean response to tropical cyclones (TCs) in the South Pacific convergence zone through a complete ocean heat budget. The TC impact analysis is based on the comparison between two long-term (1979-2003) oceanic simulations forced by a mesoscale atmospheric model solution in which extreme winds associated with cyclones are either maintained or filtered. The simulations provide a statistically robust experiment that fills a gap in the current modeling literature between coarse-resolution and short-term studies. The authors' results show a significant thermal response of the ocean to at least 500-m depth, driven by competing mixing and upwelling mechanisms. As suggested in previous studies, vertical mixing largely explains surface cooling induced by TCs. However, TC-induced upwelling of deeper waters plays an unexpected role as it partly balances the warming of subsurface waters induced by vertical mixing. Below 100 m, vertical advection results in cooling that persists long after the storm passes and has a signature in the ocean climatology. The heat lost through TC-induced vertical advection is exported outside the cyclogenesis area with strong interannual variability. In addition, 60% of the heat input below the surface during the cyclone season is released back to the oceanic mixed layer through winter entrainment and then to the atmosphere. Therefore, seasonal modulation reduces the mean surface heat flux due to TCs to about 3 × 10−3 PW in this region exposed to 10%-15% of the world's cyclones. The resulting climatological anomaly is a warming of about 0.1°C in the subsurface layer and cooling below the thermocline (less than 0.1°C).