Polar Biological Studies: Study of bacterial diversity and adaptability in snow and ice from the Larsemann Hill and the Schirmacher Oasis, Antarctica have been taken up. About 105 discrete bacterial colonies were isolated and purified. To understand the adaptability to cold environment the isolates were subjected to growth at 40°C. Twenty six isolates from the Schirmacher Oasis and 50 isolates from the Larsemann Hills area showed growth at 40°C. The protein profiling of the isolates were carried out in the range of 14.4 Kda to 97.4 Kda. Based on the similarity of the protein profile 55 isolates were short-listed and were subjected to 16 S rDNA analysis. The isolates were predominated by Bacillus flexus, B. thuringiensis, B. cereus and B. aryabhattai.
A first report on the isolation of Cellulosimicrobium cellulans bacteria in the snow deposits of the Larsemann Hills with physiological traits that were markedly different from that of the mesophilic C. cellulans type strain reveal that this genus could be more cosmopolitan than hitherto thought of and is capable of living in extreme cold environments. Carbon utilization studies demonstrated that C. cellulans preferred complex carbon substrates over simple ones, suggesting that it could play a potential role in carbon uptake in snow.
Biogeochemical and microbiological study of snow from the coastal Larsemann Hills (East Antarctica) reveal that elevated nutrient concentrations in ice cap snow seems to enhance the growth of microalgae in snow and the subsequent production of bromo-carbons leading to high bromide concentration in snow. The activated Br in the Antarctic atmosphere would react with ozone leading to BrO enhancement with subsequent DMS oxidation and production of sulphur aerosols. Since BrO based DMS oxidation is much faster than OH/NO3 pathway, elevated bromide in the Antarctica could contribute more towards the formation of cloud condensation nuclei (CCN) at the expense of ozone.
Polar Environmental Studies: Comprehensive Environmental Evaluation (CEE) of the New Indian Research Station at Larsemann Hills, Antarctica was carried out and was presented at the XXX ATCM (2007), New Delhi.
Polar Remote Sensing: An enhanced digital elevation model (DEM) of the Larsemann Hills region, (on the eastern boundary of Antarctica) was generated synergistically by using highly accurate ground-based GPS measurements, satellite-derived laser altimetry (GLAS/ ICESat) and Radarsat Antarctic Mapping Project (RAMP) DEM-based point elevation data. A DEM is essential to model the ice elevation change and address the ice mass balance.
Link between Tropical Indian Ocean Processes, Indian Ocean Dipole (IOD) and Sea-ice was carried out at the Lamont Doherty Earth Observatory, Columbia in Feb to April 2010 under the SCAR Fellowship scheme. Most remarkable correlations were obtained when the ice concentration anomalies lags Dipole mode index (DMI) by 2 years and when the ice concentration anomalies leads the DMI by one year. The reasons for these correlations are being investigated.
Last Updated On 10/22/2014 - 20:24