A5060537854- Geology and Paleoclimatology Research
- Marine and coastal ecosystems
- Isotope Analysis in Ecology
- Oceanographic and Atmospheric Processes
- Marine and fisheries research
- Tree-ring climate responses
- Marine Biology and Ecology Research
- Archaeology and ancient environmental studies
- Groundwater and Isotope Geochemistry
- Climate variability and models
- Marine and environmental studies
- Pacific and Southeast Asian Studies
- Maritime and Coastal Archaeology
- earthquake and tectonic studies
- Hydrology and Watershed Management Studies
- Geological and Geophysical Studies
- Coral and Marine Ecosystems Studies
- Plant Water Relations and Carbon Dynamics
- Geochemistry and Elemental Analysis
- Atmospheric Ozone and Climate
- Cryospheric studies and observations
- Coastal wetland ecosystem dynamics
- Pleistocene-Era Hominins and Archaeology
- Atmospheric chemistry and aerosols
- Cassava research and cyanide
Indian Institute of Tropical Meteorology
2014-2025
Ministry of Earth Sciences
2021-2024
Physical Research Laboratory
2010-2019
Savitribai Phule Pune University
2018
[1] We report the first direct estimates of N2 fixation rates measured during spring, 2009 using 15N2 gas tracer technique in eastern Arabian Sea, which is well known for significant loss nitrogen due to intense denitrification. Carbon uptake are also concurrently estimated 13C technique. The vary from ∼0.1 34 mmol N m−2d−1 after correcting isotopic under-equilibrium with dissolved air samples. These higher consistent chlorophyll a and low δ15N natural particulate organic nitrogen. Our...
Primary productivity in the sunlit surface layers of tropical oceans is mostly limited by supply reactive nitrogen ( N r ) through upwelling, 2 fixation diazotrophs , riverine flux and atmospheric deposition. The relative importance these processes varies from region to region. Using recent data on content aerosols over ocean marine new production parts northern Indian Ocean for period 1994–2006 CE, a quantitative assessment contribution deposition two biogeochemically different basins...
<title>Abstract</title> The relative abundances of ecologically sensitive and dominant benthic foraminifera (> 150 µm) in a sediment core located near the southeastern boundary Laccadive Sea Central Equatorial Indian Ocean were investigated to understand deep-water conditions past 19 kyrs. Faunal analysis from 14 samples spanning last kyrs done along with geochemical stable isotope study foraminifera. investigation revealed variability export productivity changes bottom water dissolved...
This study presents an analysis of the Indian summer monsoon (ISM) rainfall variations for a 1460-year period (1720–3180, Before Present BP: 1950 AD), based on long record stable isotopic (δ 18 O) with high temporal resolution (~annual) obtained from U-Th dated stalagmite Kadapa cave in peninsular India. proxy captures associated wet and dry monsoons decadal to centennial time-scales, together general declining trend ISM during period. It is noted that follows northern hemispheric...
Abstract Stable isotopic compositions (δ 18 O and δD) in water samples collected from Parbati River Himachal Pradesh, India, during 2002–2005 were measured to delineate the contributions different sources seasons. A seasonal cycle with high δ δD values (in ‰) spring (March May; −9.2, −58.6), intermediate winter (December February; −10.1, −65.6), low south‐west monsoon (July September; −10.9, −71.8) is observed. The d ‐excess (15.2 ± 2.1‰) are higher compared global meteoric waters indicating...
We present new data on N uptake rates and f -ratios in the north-eastern (NE) Arabian Sea, where significant amounts of Trichodesmium were spring, 2006. The measured total nitrogen ranged from 0.34 to 1.58 mmol . fixation associated with varied 0.002 0.54 estimated abundance specific 1.5 pmol trichome. Inclusion significantly changes particularly coastal stations. Nitrogen isotopic surface suspended particles suggest that recently fixed contributes as high ~79% particles. In addition, water...
Stable oxygen and hydrogen isotopic compositions (δ18O δD) of rainwater collected between 2009 2011 CE from Hailakandi, southern Assam, north-eastern India have been measured to characterize the extreme rainfall phenomena, delineate moisture sources, determine amount effect assess p rospect local proxies for paleoclimate studies. The δ18O values range +0.7 −13.8‰ while δD varies +12 −98‰. During pre-monsoon months (March May), heavy rains thunderstorms, called nor'westers (Kal Baisakhi in...