Port Blair, Andaman Islands 1975-2006 Coral Stable Isotope Data Rixen, T.; Ramachandran, P.; Lehnhoff, L.; Dasbach, D.; Gaye, B.; Urban, B.; Ramachandran, R.; Ittekkot, V. Rixen, T. Ramachandran, P. Lehnhoff, L. Dasbach, D. Gaye, B. Urban, B. Ramachandran, R. Ittekkot, V. Monsoon earth science/paleoclimate/corals and sclerosponges (delta 13C,Porites lutea,null,per mil PDB,null,corals and sclerosponges,raw,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/corals and sclerosponges (delta 18O,Porites lutea,null,per mil PDB,null,corals and sclerosponges,raw,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/corals and sclerosponges (age,null,null,year Common Era,null,corals and sclerosponges,null,null,N,null) earth science/paleoclimate/corals and sclerosponges (depth,null,null,millimeter,null,corals and sclerosponges,null,null,N,null) earth science/paleoclimate/corals and sclerosponges earth science/paleoclimate/corals and sclerosponges (Port Blair>LATITUDE 11.5048>LONGITUDE 92.6931) North Atlantic climate variations are reflected in sedimentary records from the northern Indian Ocean in which two basins, the Arabian Sea and the Bay of Bengal, are strongly affected by the monsoon. Contrary to the Bay of Bengal the Arabian Sea plays an important role in the global marine nitrogen cycle. In its mid-water oxygen minimum zone (OMZ) bioavailable fixed nitrogen is reduced to nitrogen gas (NO3- -> N2), whereas oxygen concentrations are slightly above the threshold of nitrate reduction in the OMZ of the Bay of Bengal. A coral colony (Porites lutea) growing south of Port Blair on the Andaman Islands in the Bay of Bengal was studied for its response to changes in the monsoon system and its link to temperature changes in the North Atlantic Ocean, between 1975 and 2006. Its linear extension rates, d13C and d18O values measured within the coral skeleton reveal a strong seasonality, which seems to be caused by the monsoon-driven reversal of the surface ocean circulation. The sampling site appears to be influenced by low salinity Bay of Bengal Water during the NE monsoon (boreal winter) and by the high salinity Arabian Sea Water during the SW monsoon in summer. The high salinity Arabian Sea Water circulates along with the Summer Monsoon Current (S-MC) from the Arabia Sea into the Bay of Bengal. Decreasing d18O and reconstructed salinity values correlate to the increasing SSTs in the North Atlantic Ocean indicating a reduced influence of the S-MC at the sampling site in the course of northern hemispheric warming. During such periods oxygen-depletion became stronger in the OMZ of the Arabian Sea as indicated by the sedimentary records. A reduced propagation of oxygen-depleted high salinity Arabian Sea Water into the Bay of Bengal could be a mechanism maintaining oxygen concentration above the threshold of nitrate reduction in the OMZ of the Bay of Bengal in times of global warming. STUDY NOTES: Andaman Islands coral stable isotope data at monthly resolution. A Porites lutea colony from a reef south of Port Blair was sampled in March 2006, at a water depth of ~6 m. The core has a diameter of 6.4 cm and a length of ~37 cm. The d18O and d13C values were calibrated relative to NBS19 and are given in per mil deviation from the PDB. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Rixen, T. Investigator : Ramachandran, P. Investigator : Lehnhoff, L. Investigator : Dasbach, D. Investigator : Gaye, B. Investigator : Urban, B. Investigator : Ramachandran, R. Investigator : Ittekkot, V. 2010-10-18 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/9639 https://www1.ncdc.noaa.gov/pub/data/paleo/coral/indian_ocean/port-blair2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/coral/indian_ocean/port-blair2010.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/indian_ocean/port-blair2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/coral/indian_ocean/port-blair2010.txt English https://www.ncdc.noaa.gov/paleo/study/9639 https://www1.ncdc.noaa.gov/pub/data/paleo/coral/indian_ocean/port-blair2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/coral/indian_ocean/port-blair2010.txt Rixen, T., P. Ramachandran, L. Lehnhoff, D. Dasbach, B. Gaye, B. Urban, R. Ramachandran, and V. Ittekkot. 2010. Impact of monsoon-driven surface ocean processes on a coral off Port Blair on the Andaman Islands and their link to North Atlantic climate variations. Global and Planetary Change. START YEAR: 1975 AD * END YEAR: 2006 AD 92.6931 11.5048 92.6931 11.5048