Reconstruction of annual accumulation rate on firn synchronizing H₂O₂ concentration data with an estimated temperature record

Abstract. This work deals with two distinct datasets, a well preserved H₂O₂ concentration data from firn cores at a high deposition location and a temperature time series, estimated from the daily records from four Antarctic stations around the Antarctic Peninsula. With them we have produced a time scale, an ice–core chronology, for the 133  deep borehole DP-07-1 from Plateau Detroit, Antarctic Peninsula. We constructed the chronology through a non-linear pairing transformation of the two series, based entirely on mathematical optimization, compensating the peroxide frequency scaling, reflecting the gradual thinning of the annual firn layers with depth. We resorted to a dynamic time warping algorithm to find an optimal alignment between the two data series, allowing for the thinning of the annual firn layers with depth and the estimation of their original thicknesses at time of deposition. The core chronology spanning from Jan-1980 to Dec-2010 for the borehole reach, a time frame of a mere 30 years period, revealing a fairly stable 11 year average for the accumulation rate of 2.5 m w.e./y.