[1] Stable isotope records of oxygen and hydrogen were studied from a 65 m long ice core retrieved from central Dronning Maud Land, East Antarctica, in order to reconstruct the coastal Antarctic climate variability during the last century and its relation to the Southern Annular Mode (SAM) and El Niño-Southern Oscillation (ENSO). The d18 O records showed a significant relation to the SAM with a dominant ∼4 years variability, except during specific periods (1918-1927, 1938-1947, and 1989-2005) when ENSO teleconnection was established through the in-phase relation between SAM and Southern Oscillation Index (SOI). The combined influence of ENSO and SAM was seen on surface air temperatures in this region mainly during the austral summer season from 1989 to 2005. Further, a significant relationship between d 18 O and SAM was observed on a decadal scale, which overrides the intermittent influence of ENSO. Major shifts in the deuterium excess record were observed during periods of ENSO teleconnections, which support a shift in moisture source regions during the periods of stronger ENSO teleconnections. Surface air temperatures estimated using the d 18 O-T spatial slope for this region depicted a significant warming of 1°C for the past century. The study reveals that throughout the last century, SAM was the dominant mode of climatic variability in the coastal region of central Dronning Maud Land on a decadal scale.

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Spatial distribution of pH, electrical conductivity (EC), total dissolved solids (TDS), fluoride and total iron content of ground water samples collected from the muvattupuzha river basin, Kerala, India, has been studied for pre monsoon and post monsoon periods of year 2001. Results showed the groundwater of the basin is acidic for which the pH values ranged between 5.5 and 8.0. Average EC was found to be less than 100 microS/cm, for most of the study region. The pre monsoon minimum and maximum TDS were found as 25.6 and 227.84 mg/L respectively, where as post monsoon values ranged between 16 and 162.56 mg/L. The relatively low EC and TDS values found both during the seasons in the lateritic terrain of the river basin signifies the lower residence time of ground water with the country rock. This makes the groundwater quality of this river basin as good. Pre monsoon season samples showed high total iron content than that during the post monsoon period. During the study period values of the fluoride contents were found to be within the permissible limits.

Abstract. Cochin backwaters, a micro tidal estuary, undergo a characteristic transformation from a riverdominated system during summer monsoon to a tide-dominant system during pre-monsoon season. The present study observes that as the river flow weakens after monsoon, the flushing of the estuary diminishes and the nitrogen and phosphorous loadings through anthropogenic activities (industries) and sediment re-suspension alter the nutrient stoichiometry substantially. The increased tidal activity during pre-monsoon changes the estuary into a vertically mixed, eutrophic and flow-restricted system supporting an enhanced organic production. This implies that monsoon-induced hydrology plays an important role in regulating the nutrients, secondary production and even the migrant fauna of the estuary. The system is delicately poised, as continuous release of pollutants including nutrients into this estuary would suppress fish and shell fish production, where only pollution tolerant species can exist.

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