Browsing Institute's contributions by Author "Naidu, P.D."
Now showing items 1-20 of 69
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70 kyr record of denitrification and oxygenation changes in the eastern Arabian Sea
Godad, S.P.; Naik, S.S.; Naidu, P.D. (Geochemical Society of Japan, 2017)A 70 kyr record of ?15N from the eastern Arabian Sea, Core AAS9/21 was investigated. High ?15N values during interglacials and low ?15N values during glacials are documented, which mimics the global ?15N records in the ... -
A 16-kyr Record of Ocean Circulation and Monsoon Intensification From the Central Bay of Bengal
Naik, S.S.; Basak, C.; Goldstein, S.L.; Naidu, P.D.; Naik, S.N. (John Wiley & Sons, 2019)The monsoonal signal dominates most climate records from the Indian Ocean. As a consequence, conventional stable isotope tracers have not been effective at tracking ocean circulation in the Indian Ocean and distinguishing ... -
A coherent response of Southern Indian Ocean to the Antarctic climate: Implications to the lead, lags of atmospheric CO2 during deglaciation
Narayana, A.C.; Naidu, P.D.; Bhavani, P.G.; Ahmad, M. (Springer, 2020)A record of delta18Oc from the Indian sector of Southern Ocean and atmospheric CO2, and delta18O of European Project for Ice Coring in Antarctica (EPICA) and Greenland Ice Sheet Project 2 (GISP2) reveals that a coherent ... -
A comparison of Globigerinoides ruber calcification between upwelling and non-upwelling regions in the Arabian Sea
Naik, S.S.; Godad, S.P.; Naidu, P.D.; Ramaswamy, V. (Indian Academy of Sciences, 2013)Shell weights of planktonic foraminifera species Globigerinoides ruber in the size range of 300–355 mew m were measured from sediment traps in the western and eastern Arabian Sea which represent upwelling and non-upwelling ... -
A first look at past sea surface temperatures in the equatorial Indian Ocean from Mg/Ca in foraminifera
Saraswat, R.; Nigam, R.; Weldeab, S.; Mackensen, A.; Naidu, P.D. (AGU, 2005)Sea surface temperature (SST) for the central equatorial Indian Ocean, has been reconstructed over the last approx. 137 kyr, from Mg/Ca of the planktonic foraminiferal species Globigerinoides ruber. According to our record ... -
A first look at the dinoflagellate cysts abundance in the Bay of Bengal: implications on Late Quaternary productivity and climate change
Naidu, P.D.; Patil, J.S.; Narale, D.D.; Anil, A.C. (Current Science Association, 2012)Abundance and composition of dinoflagellate cysts in a sediment core (SK218/1) from the Bay of Bengal were examined for the last 23 kyr. Cyst abundance at this site varied from 20 to 153 cysts/g dry wt, which is far less ... -
A review on Holocene climate changes in Indian subcontinent
Naidu, P.D. (Geological Society of India, 1999)Since the collision of Indian plate with Eurasia, the Indian subcontinent has experienced minor tectonic and major climatic changes. Summer monsoon plays an important role in the local and regional climate of Asia. General ... -
Abrupt climate-induced changes in carbonate burial in the Arabian Sea: Causes and consequences.
Naidu, P.D.; Singh, A.D.; Ganeshram, R.S.; Bharti, S.K. (American Geophysical Union, 2014)We present high-resolution records of aragonite contents and pteropods abundance in two sediment cores (SK 17 and MD 76–131) within the Oxygen Minimum Zone (OMZ) of the eastern Arabian Sea. We show large increases in ... -
Asia Oceania Geosciences Society's First Annual Meeting. A report
Naidu, P.D.; Bhattacharya, G.C.; Chaubey, A.K.; Krishna, K.S. (Geological Society of India, 2004) -
Asian monsoon variability, cyclicities, and forcing mechanisms
Naidu, P.D. (National Institute of Oceanography, India, 2007) -
Atypical delta sup(13) C signature in Globigerina bulloides at the ODP site 723A (Arabian Sea): Implications of environmental changes caused by upwelling
Naidu, P.D.; Niitsuma, N. (Elsevier, 2004)Production of Globigerina bulloides generally increases during upwelling in the tropical ocean and, in particular, during southwest monsoon season in the Arabian Sea. We studied the delta sup(13) C signatures of Globigerina ... -
Bay of Bengal Exhibits Warming Trend During the Younger Dryas: Implications of AMOC
Panmei, C.; Naidu, P.D.; Mohtadi, M. (Wiley, 2017)A sharp decline in temperature during the Younger Dryas (YD) preceding the current warmer Holocene is well documented in climate archives from the Northern Hemisphere high latitudes. Although the magnitude of YD cooling ... -
Boron/calcium ratios in Globigerinoides ruber from the Arabian Sea: Implications for controls on boron incorporation
Naik, S.S.; Naidu, P.D. (Elsevier, 2014)Culture and downcore studies have been used to argue that B/Ca ratios in planktic foraminifera are correlated with seawater pH and may record seawater borate/bicarbonate ratios, although other factors may also control B/Ca. ... -
Calcite dissolution along a transect in the western tropical Indian Ocean: A multiproxy approach
Naik, S.S.; Naidu, P.D. (American Geophysical Union, 2007)Three paleocarbonate ion proxies, size index, planktonic foraminifera shell weight, and calcite crystallinity, have been employed here to a set of core top samples from the western tropical Indian Ocean in the water depth ... -
Carbon and oxygen isotope time series records of planktonic and benthic foraminifera from the Arabian Sea: Implications on upwelling processes
Naidu, P.D.; Niitsuma, N. (Elsevier, 2003)Oxygen and carbon isotopic analyses have been performed on the tests of Globigerina bulloides and Pulleniatina obliquiloculata (planktonic foraminifera) and Uvigerina excellens (benthic foraminifer) to study the evolution ... -
Carbonate and carbon fluctuations in the Eastern Arabian Sea over 140 ka: Implications on productivity changes?
Guptha, M.V.S.; Naidu, P.D.; Haake, B.G.; Schiebel, R. (Elsevier, 2005)Biological productivity in the western Arabian Sea was higher during interglacial than glacial times. In the eastern Arabian Sea productivity was higher during the glacials compared to interglacials, which is in sharp ... -
Carbonate and organic carbon content changes over last 20 ka in the Southeastern Arabian Sea: Paleoceanographic implications
Narayana, A.C.; Naidu, P.D.; Shinu, N.; Nagabhushanam, P.; Sukhija, B.S. (Elsevier, 2009)Two Gravity cores (AAS 38-4 and AAS 38-5) recovered from the eastern Arabian Sea were analyzed for calcium carbonate (CaCO3), organic carbon, aluminium (Al) and titanium (Ti) in order to understand the calcium carbonate ... -
Carbonate preservation during the 'mystery interval' in the northern Indian Ocean
Naik, S.S.; Naidu, P.D. (Terra Scientific Publishing Company, 2016)To understand carbonate dissolution and/or preservation on the sea floor since the Last Glacial Maximum (LGM), we measured shell weights of planktonic foraminifera Globigerinoides ruber from four sediment cores retrieved ... -
Coherent response of the Indian Monsoon Rainfall to Atlantic Multi-decadal Variability over the last 2000 years
Naidu, P.D.; Ganeshram, R.; Bollasina, M.A.; Panmei, C.; Nurnberg, D.; Donges, J.F. (2020)Indian Summer Monsoon (ISM) rainfall has a direct effect on the livelihoods of two billion people in the Indian-subcontinent. Yet, our understanding of the drivers of multi-decadal variability of the ISM is far from being ... -
Contrasts in calcium carbonate dissolution above the lysocline in the equatorial Indian Ocean over the last ~40 ka
Yadav, Ramanand; Naik, S.S.; Naidu, P.D. (Elsevier, 2022)Understanding calcite dissolution above the lysocline is crucial to comprehend the oceanic calcium carbonate cycle. To understand past calcite dissolution in sediments from above the lysocline, we use multiple dissolution ...