Description
Summary:"LD2000" Isotope record: 1800AD-1999AD" This data set is that used in Schneider et al., 2006 and should be cited as such: Schneider, D. P., Steig, E. J., van Ommen, T. D., Dixon, D. A., Mayewski, P. A., Jones, J. M. and Bitz, C. M. 2006. Antarctic temperatures over the past two centuries from ice cores. Geophysical Research Letters." This record, referred to as LD2000, takes the record to end 1999AD. It is based on fine annual isotope data (~10-20 samples/year), here averaged to annual values. The dating of the record is based on absolute counting of years in isotope and trace ion data. This record is a stack in upper portions of five different cores taken near the main DSS drill site on Law Dome, Wilkes Land. Dating of DSS/DSS97/DSS99 "Anne S. Palmer, Tas D. van Ommen, A. J. Curran, Mark, Vin Morgan, Joe M. Souney, and Paul A. Mayewski. High precision dating of volcanic events (A.D. 1301-1995) using ice cores from Law Dome, Antarctica. J. Geophys. Res., 106(D22):28,089-28,096, 2001" Calibration of the isotopes: Other "Tas van Ommen and Vin Morgan. The peroxide record from the DSS ice core, Law Dome, Antarctica: Preliminary results. In E.W. Wolff and R.C. Bales, editors, Chemical Exchange Between the Atmosphere and Polar Snow, volume 43 of NATO Advanced Sciences Institutes Series I, pages 623-627. Springer-Verlag, 1996." "Tas D. van Ommen and Vin Morgan. Calibrating the ice core paleothermometer using seasonality. J. Geophys. Res., 102(D8):9351-9357, 1997" Other information "The core is dated so that the 'year' runs from one isotope maximum to the next, with the use of trace chemical and peroxide data to help resolve" true mid-summer isotopic maxima from occasional maxima that are not mid-summer. Studies show that the mean timing of the isotope maximum "at Law Dome is around January 10: eg. See van Ommen and Morgan, 1996 and van Ommen and Morgan, 1997" From the abstract of the referenced paper: We present a reconstruction of Antarctic mean surface temperatures over the past two centuries based on water stable isotope records from high-resolution, precisely dated ice cores. Both instrumental and reconstructed temperatures indicate large interannual to decadal scale variability, with the dominant pattern being anti-phase anomalies between the main Antarctic continent and the Antarctic Peninsula region. Comparative analysis of the instrumental Southern Hemisphere (SH) mean temperature record and the reconstruction suggests that at longer timescales, temperatures over the Antarctic continent vary in phase with the SH mean. Our reconstruction suggests that at longer timescales, temperatures over the Antarctic continent vary in phase with the SH mean. Our reconstruction suggests that Antarctic temperatures have increased by about 0.2 degrees C since the late nineteenth century. The variability and the long-term trends are strongly modulated by the SH Annular Mode in the atmospheric circulation. This work was completed as part of ASAC project 757 (ASAC_757).