Australasian Monsoons

The warmest surface waters on earth are in the western Pacific warm pool. This region is a net exporter of water vapour to higher latitudes, most transported by monsoon winds.  Changes in temperature of this region influence the amount of poleward water vapor transport.  The monsoons, in turn, influence surface properties of the western Pacific.  My colleagues and I, as well as other researchers, have found changes in surface water properties on orbital to millennial time scales.

We use stable isotopes and Mg/Ca of planktonic foraminifera to reconstruct changes in surface temperature and the oxygen isotope composition of sea water. We also use organic geochemistry to infer changes regional convection.

Related Publications

• Dubois, N., D. W. Oppo, V. V. Galy, M. Mohtadi, S. van der Kaars, J E. Tierney, Y. Rosenthal, T. I. Eglinton, A. Lückge, B. K. Linsley,  Indonesian vegetation response to changes in rainfall seasonality over the past 25,000 years, Nature Geoscience, DOI: 10.1038/NGEO2182, 2014. Proof pdf
• Mohtadi, M., M. Prange, D. W. Oppo, R. De Pol-Holz, U.Merkel, X. Zhang, S. Steinke, A. LückgeNorth Atlantic Forcing of Tropical Indian Ocean Climate, Nature, 509,76–80 2014. doi:10.1038/nature13196. Proof pdf
• Gibbons, F.T., Oppo, D.W., Mohtadi, M., Rosenthal, Y., Cheng, J., Liu, Z., Linsley, B.K.,  2014. Deglacial δ18O and hydrologic variability in the tropical Pacific and Indian Oceans. Earth Planet. Sci. Lett. 387, 240–251.
  http://www.sciencedirect.com/science/article/pii/S0012821X13006663
• Tierney, J. E., D. W. Oppo, A. N. LeGrande, Y. Huang, Y. Rosenthal, and B. K. Linsley, The influence of Indian Ocean atmospheric circulation on Warm Pool hydroclimate during the Holocene epoch, J. Geophys. Res., 117, D19108, doi:10.1029/2012JD018060, 2012.
• Muller, J., J. F. McManus, D. W. Oppo, and R. François, Strengthening of the Northeast Monsoon over the Flores Sea, Indonesia, at the time of Heinrich event 1, Geology, 40, 635–638, 2012.
• Mohtadi M., Oppo D.W., Lückge A., De Pol-Holz R, Steinke S., Groeneveld J., Hemme N., Hebbeln D., 2011. Reconstructing the thermal structure of the upper ocean: insights from planktic foraminifera shell chemistry and alkenones in modern sediments of the tropical eastern Indian Ocean. Paleoceanography 26, PA3219, doi:10.1029/2011PA002132.
• Mohtadi, M., D. W. Oppo, S. Steinke, J. W. Stuut, E. C. Hathorne, J. Groeneveld, D. Hebbeln, A. Lückge, Glacial to Holocene swings of the Australian-Indonesian monsoon, Nature Geosciences DOI: 10.1038/NGEO1209 (2011).
• Tierney, J. E, D.W. Oppo, J. M. Russell, B. K. Linsley, Y. Rosenthal, Coordinated hydrological regimes in the Indo-Pacific region during the past two millennia, region during the past two millennia, Paleoceanography, doi:10.1029/2009PA001871, 2010.
• Oppo, DW, Y Rosenthal, BK Linsley, 2000-year-long temperature and hydrology reconstructions from the Indo-Pacific Warm Pool, Nature, 460 113-160, doi:10.1038/nature08233, 2009.