High-Resolution Tritium Profile in an Ice Core from Camp Century, Greenland

Abstract

We measure ³H in an ice core from Camp Century. The temporal distribution of ³H concentration in the ice core corresponds generally well with the historical record of explosive yields of atmospheric nuclear weapons tests. Maximum ³H values observed in 1962-1963 are comparable to those in ice core or precipitation in many other locations in the Northern Hemisphere. There is no indication that significant ³H contamination was locally released into the air during the operation of the Camp Century reactor. It is, however, somewhat surprising that several prominent ³H peaks are still observed after 1980. We suggest that these are associated with airborne ³H releases from the civil nuclear industry. A wavelet analysis during 1970-2017 indicates the primary frequency of variability in the ³H record is annual ³H peaks. These annual peaks can be combined with the ³H spikes from global fallout of known nuclear weapons tests to benchmark and evaluate theoretical ice core dating scales back to the 1950s. A positive correlation is observed between annual ³H average concentration and variability of Arctic Oscillation (AO). This highlights the value of ³H as a potential tracer for air masses and airborne pollutants in the Arctic.

Keywords: Camp Century; ice core; source; tracer application; tritium.