Diagnose oscillation properties observed in an Antarctic ice core oxygen isotope record

We investigate water isotope ratio profile obtained in a shallow ice core drilled at Dome Fuji, East Antarctica. Two sets of time series will be discussed; the first set was analyzed at NIPR (National Institute of Polar Research) with temporal resolution of about 5 years for the past 1900 years, and the second was obtained at RIKEN very recently with temporal resolution of less than a year for the past 400 years. Paying our attention on uncertainty in the depth-age relation, time series analyses to the measured oxygen isotope variations will be presented. A preliminary result for the former time series shows a ~200-year periodicity, which is by chance the same with one of solar activity cycles reported from tree ring studies. We note that snow and ice core samples obtained at Dome Fuji are known to contain much information on the stratosphere than those recovered from other sites in both the hemisphere. Considering this, we will further discuss possible mechanism to cause oscillation in oxygen isotope record in a Dome Fuji ice core.