Using the sunspot cycle to date ice cores

Evidence for substantial accumulation rate variability in Antarctica during the Holocene, through synchronization of CO 2 in the Taylor Dome, Dome C and DML ice cores

“…The accumulation rate prior to 8 ky is lower than we calculated, supporting our primary conclusion that accumulation rates have significantly increased through the Holocene. There is a smaller amount of dynamic thinning than calculated [21,22]. We consider this unlikely, but if it is correct, then we would have overestimated accumulation rate in the early part of the record, and that would also be consistent with our primary conclusion.…”

“…Here we use an alternative approach, which minimizes the mismatch between accumulation rates obtained from two different methods. The derivative of the gas age timescale is used to obtain an initial layer thickness profile, which is corrected for layer thinning (using flow models [21,22]) to obtain an initial accumulation rate estimate. This estimate is used to calculate Dage, using the Herron -Langway empirical densification model [25] with stable isotopes as the proxy for temperature.…”

“…This timescale was created independently from the Brook et al [20] gas age timescale. For the Holocene, a 2-D finite element glacier flow model [21,22] was applied. The accumulation rate was assumed to be constant over the Holocene and adjusted to match a tie point associated with the end of the Younger Dryas.…”

Cosmogenic Be-10 and the Solid Earth: Studies in Geomagnetism, Subduction Zone Processes, and Active Tectonics

“…Carbon-14 activity (Δ 14 C = 14 C/ 12 C) records obtained from tree rings and 10 Be records from polar ice cores (Stuiver 1961;Eddy 1976;Stuiver and Quay 1980;Raisbeck et al 1981b;Beer et al 1988;Damon and Sonnett 1991;Stuiver and Braziunas 1993;Bard et al 1997) indicate that high production rates correspond to periods of low sunspot activity. In addition, periodicities of 11, 22, 200, 400, and ~2400 years have been observed in these records (Beer et al 1983(Beer et al , 1988Sonnett and Seuss 1984;Damon et al 1989;Stuiver andBraziunas 1989, 1993;Suess and Linick 1990;Haubold and Beer, 1992;Steig et al 1996Steig et al , 1998Finkel and Nishiizumi 1997;Bard 1998;Cini Castagnoli et al 1998;Wagner et al 2001). …”

“…modulation cycles can be identified in 10 Be production rates. Radionuclide investigations using tree rings and ice cores have revealed century and decade scale variations in the production rates of 14 C and 10 Be (e.g., Beer et al 1988;Stuiver and Braziunas 1989;Beer et al 1990;Stuiver and Braziunas 1993;Steig et al 1998;Wagner et al 2001) which have been attributed to solar modulation of the primary cosmic ray flux. A similar approach in lithologically uniform, high-deposition rate sediments could potentially resolve long-period variations in the geomagnetic field.…”