@article {1835, title = {The Passage of the Bomb Radiocarbon Pulse into the Pacific Ocean}, journal = {Radiocarbon}, volume = {52}, year = {2010}, note = {Sp. Iss. 2696jo Times Cited:7 Cited References Count:38 }, month = {2010}, pages = {1182-1190}, abstract = {We report and compare radiocarbon observations made on 2 meridional oceanographic sections along 150 degrees W in the South Pacific in 1991 and 2005. The distributions reflect the progressive penetration of nuclear weapons-produced (14)C into the oceanic thermocline. The changes over the 14 yr between occupations are demonstrably large relative to any possible drift in our analytical standardization. The computed difference field based on the gridded data in the upper 1600 m of the section exhibits a significant decrease over time (approaching 40 to 50 parts per thousand in Delta(14)C) in the upper 200-300 m, consistent with the decadal post-bomb decline in atmospheric (14)C levels. A strong positive anomaly (increase with time), centered on the low salinity core of the Antarctic Intermediate Water (AAIW), approaches 50-60 parts per thousand in Delta(14)C, a clear signature of the downstream evolution of the (14)C transient in this water mass. We use this observation to estimate the transit time of AAIW from its "source region" in the southeast South Pacific and to compute the effective reservoir age of this water mass. The 2 sections show small but significant changes in the abyssal (14)C distributions. Between 1991 and 2005, Delta(14)C has increased by 9 parts per thousand below 2000 m north of 55 degrees S. This change is accompanied overall by a modest increase in salinity and dissolved oxygen, as well as a slight decrease in dissolved silica. Such changes are indicative of greater ventilation. Calculation of "phosphate star" also indicates that this may be due to a shift from the Southern Ocean toward North Atlantic Deep Water as the ventilation source of the abyssal South Pacific.}, keywords = {AMS, antarctic intermediate water, anthropogenic co2, atlantic, c-14 data, carbon, distributions, graphite, south-pacific, tritium}, isbn = {0033-8222}, author = {Jenkins, W. J. and Elder, K. L. and McNichol, A. P. and von Reden, K.} } @article {2252, title = {High-precision radiocarbon age calibration for terrestrial and marine samples}, journal = {Radiocarbon}, volume = {40}, year = {1998}, note = {155qrTimes Cited:705 Cited References Count:31 }, month = {1998}, pages = {1127-1151}, abstract = {Single-year and decadal radiocarbon tree-ring ages are tabulated and discussed in terms of C-14 age calibration. The single-year data form the basis of a detailed 14C age calibration curve for the cal AD 1510-1954 interval ("cal" denotes calibrated). The Seattle decadal data set (back to 11,617 cal sp, with 0 sp = AD 1950) is a component of the integrated decadal INTCAL98 C-14 age curve (Stuiver et al. 1998). Atmospheric C-14 ages can be transformed into C-14 ages of the global ocean using a carbon reservoir model. INTCAL98 C-14 ages, used for these calculations, yield global ocean C-14 ages differing slightly from previously published ones (Stuiver and Braziunas 1993b). We include discussions of offsets, error multipliers, regional C-14 age differences and marine C-14 age response to oceanic and atmospheric forcing.}, keywords = {ad 1950-500 bc, c-14 data, decadal calibration, reservoir ages, time scale}, isbn = {0033-8222}, author = {Stuiver, M. and Reimer, P. J. and Braziunas, T. F.} }