Season :    2010

Voyage :     4

Cruise Name :     Southern Ocean Expedition 2010

Voyage Classification :     Ocean Science, Southern Ocean Studies

Ship Name :     ORV Sagar Nidhi

Name of Chief Scientist / Leader :     Dr. N. Anilkumar, NCPOR, Goa.

Name of Deputy Chief Scientist / Leader :     Mr. K.P. Krishnan, NCPOR, Goa

The main objective of this cruise was to collect multi-disciplinary data from the Indian sector of the Southern Ocean up to the Antarctic continental shelf region. A team of 18 scientists from National Centre for Antarctic & Ocean Research (NCAOR), Cochin University of Science and Technology (CUSAT), Central Marine Fisheries Research Institute (CMFRI), Goa University and three engineers from NORINCO participated in this cruise. Continuous observations for atmospheric parameters were made in the entire cruise track using AWS, Athelometer, Nephelometer, High Volume Air sampler etc. The current structure in the track was observed continuously using Acoustic Doppler Current Profiler. The sub-bottom profiler was operational only at shallow regions. Surface Sea water samples were collected from 114 stations at one-degree interval along the entire cruise track. A total of 123 XCTD/XBTs probes were launched and 32 Portable CTD operations were carried out from 28°S 57°30’E onwards for temperature and salinity profiles. CTD with rosette was operated at 12 stations from 39°S 57°30’E onwards for water sample collection to understand the chemical and biological changes from the subtropical to polar regimes and in the coastal waters of Antarctica. The seawater samples were collected from different depths upto 120m for analysing various biogeochemical parameters. At 12 sampling locations Multiple Plankton Net (MPN) of mesh size 200μm was operated to collect mezzo zooplankton samples from the upper 500m-water column. Indian Ocean Standard Net of mesh size 300 μm was towed for 10-15 minutes with 2 knouts ship speed at 21 stations to study the distribution of Krill and surface zooplankton in the study area. Nine gravity corer operations were carried out during this expedition,however only 3 sediment cores were collected due to the bottom topography of the region. Core sediments were collected from 4 locations in the Antarctic Coastal waters using a small corer of length 1m. Although Vaan Veen grab was operated at 4 locations in this region sample was collected at only one location. It is expected that this multi-disciplinary oceanographic data collected in the Indian sector of Southern Ocean as well as in the Indian Ocean tropical region will help to bring out new insight in our scientific understandings. During the entire cruise, there were several occasions of instrumental errors and equipment failure. Even in the bad weather/rough sea conditions tremendous efforts were made by the expedition members for data collection, which could help in a better understanding of the unknown areas of Southern Ocean.

The Expedition was very successful and all the planned research activities were accomplished. For more details please refer Cruise report.

From	Depart	To	Arrive
Marmugao, Goa	01/12/2010	Marmugao, Goa	25/03/2010

Physical Oceanography To describe the thermohaline structure and water mass transformations Geostrophic mass transport General Circulation structure of upper ocean Upper ocean heat content and heat budget studies. Air- sea interaction studies Chemical Oceanography To study the spatial variation of different chemical parameters like nutrients, Total inorganic and organic carbon, alkalinity and pH To study the spatial variability of trace metals Biological Oceanography To study abundance, diversity and distribution of bacterioplankton, phytoplankton, microzooplankton and mesozooplankton Studies on the bacterial and primary productivity and associated biological process from various frontal regimes. Resource survey and ecology of Krill dwelling in southern ocean surface waters.Geology To decipher the local heterogeneity in sediment transport pathways and sources to the sediments during late Quaternary. To trace the paths of ACC flow and AABW using the detrital source signals within the Sub-Antarctic Frontal zone. To study the temporal variability in micropalaeontological (study of abundance and stable isotopic variation of planktic and benthic foraminifera and diatom), major, minor and trace element records during the late Quaternary. To reconstruct the palaeoproductivity changes associated with the different oceanic regimes during the late Quaternary. To study the glacial-interglacial changes in palaeoclimatic and palaeoceanographic processes during the late Quaternary and to understand the global palaeoclimatic changes To investigate the role played by the southern ocean in the evolution of monsoon and the establishing a relationship between circulation phenomena in the southern ocean.

Please refer Voyage report

Please refer Voyage report

Please refer Voyage report