Rarotonga 2R Coral d18O and Sr/Ca, PAGES Australasia 2k Version Linsley, B.K. Linsley, B.K. PAGES 2k Network PAGES Australasia 2k 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 (delta 18O,Porites lutea,null,per mil VPDB,Sep-Feb,corals and sclerosponges,averaged,isotope ratio mass spectrometry,N,seasonal averages) earth science/paleoclimate/corals and sclerosponges (strontium/calcium,Porites lutea,null,millimole per mole,Sep-Feb,corals and sclerosponges,averaged,inductively-coupled plasma atomic emission spectroscopy,N,seasonal averages) earth science/paleoclimate/corals and sclerosponges (Rarotonga 2R>LATITUDE -21.23>LONGITUDE -159.83) The South Pacific Convergence Zone (SPCZ) is the largest and most persistent spur of the Intertropical Convergence Zone. At the southeastern edge of the SPCZ near 170W and 15 20S a surface ocean salinity frontal zone exists that separates fresher Western Pacific Warm Pool water from saltier and cooler waters in the east. This salinity front is known to shift east and west with the phase of the El NinËœo Southern Oscillation. We have generated subannually resolved and replicated coral oxygen isotopic time series from Fiji (17S, 179E) and Rarotonga (21.5S, 160W) that have recorded interannual displacements of the salinity front over the last 380 years and also indicate that at lower frequencies the decadal mean position of the salinity front, and eastern extent of the SPCZ, has shifted east-west through 10 to 20 of longitude three times during this interval. The most recent and largest shift began in the mid 1800s as the salinity front progressively moved eastward and salinity decreased at both sites. Our results suggest that sea surface salinity at these sites is now at the lowest levels recorded and is evidence for an unprecedented expansion of the SPCZ since the mid 1800s. The expansion of the SPCZ implies a gradual change in the South Pacific to more La Nina-like long-term mean conditions. This observation is consistent with the ocean thermostat mechanism for the Pacific coupled ocean-atmosphere system, whereby exogenous heating of the atmosphere would result in greater warming in the western Pacific and a greater east-west surface temperature gradient. STUDY NOTES: Uploaded by R. Neukom, data obtained from NOAA Paleo DB. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Linsley, B.K. 2013-05-15 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/1003989 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/pages2k/australasia2k/Rarotonga.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/east_pacific/rarotonga2006.txt https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/pages2k/australasia2k/Rarotonga.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/east_pacific/rarotonga2006.txt English https://www.ncdc.noaa.gov/paleo/study/1003989 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/pages2k/australasia2k/Rarotonga.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/east_pacific/rarotonga2006.txt Linsley, B.; Wellington, G.; Schrag, D2000Decadal Sea Surface Temperature Variability in the Subtropical South Pacific from 1726 to 1997 ADScience2901145-114910.1007/s00382-010-0794-2 Linsley, B.K., A. Kaplan, Y. Gouriou, J. Salinger, P.B. deMenocal, G.M. Wellington, and S.S. Howe2006Tracking the extent of the South Pacific Convergence Zone since the early 1600sGeochemistry, Geophysics, Geosystems7Q0500310.1029/2005GC001115 START YEAR: 1762 AD * END YEAR: 1996 AD -159.83 -21.23 -159.83 -21.23