Conveners
Applications in Oceanography
- Marcus Christl (ETH Zurich)
Applications in Oceanography
- Liping Zhou (Peking University)
Description
Using the AMS to study sedimentation rates and records, or tracing ocean currents.
Strontium-90 ($^{90}$Sr) is an anthropogenic radionuclide, which, due to its radiological relevance, has been most intensively monitored in the past. In terms of initial activity, over 630 PBq of this radionuclide have been distributed globally from stratospheric fallout of bomb-testing, and there are more localized contributions from tests, accidents, and releases from reprocessing plants. In...
The Southern Ocean is suitable for detecting water masses containing anthropogenic $^{129}$I (T$_{1/2}$: 15.7 million years) tracer since $^{129}$I in the Southern Ocean is 3–6 orders of magnitude lower than that in the Northern Hemisphere. This study aimed to clarify seawater circulation in the Southern Ocean by vertical cross-sectional observations of dissolved $^{129}$I and water mass...
The Arctic, a region highly sensitive to global climate change, has experienced a temperature increase exceeding four times the global average rate since the onset of the industrial era. Concurrently, warmer and saltier Atlantic water is encroaching further northward into the Arctic Ocean, driving the phenomenon known as "atlantification." These shifts have led to significant Arctic sea ice...
Over the last deglaciation, ventilation of ocean circulation has been key regulators of deep-sea carbon release, controlling climate change on centennial to millennial time scales. However, paleoceanographic reconstructions documenting changes in deep-ocean ventilation using 14C- foraminifera dating, may bear multidimensional explanations, obfuscating the roles of ocean ventilation played on...
The Southern Atlantic continental shelf of Africa is an almost blank area regarding available information on the presence of anthropogenic radionuclides, namely actinides. The coast of Namibia, part of the northern Benguela Upwelling System, was the target of the first two studies reporting 236U, 237Np, 239Pu and 240Pu in seawater [1,2]. The obtained 236U and 237Np inventories and the...
Uranium-233 (233U) and uranium-236 (236U) in the environment mainly originate from human nuclear activities. Based on the long half-lives and high solubility of uranium, 236U and 233U can be used as powerful tracers for the investigation of oceanographic and environmental processes. However, insufficient work limits the understanding of the source items of anthropogenic 233,236U in the South...
The development of 14C measurement techniques and icebreaking research vessels especially encourage and support polar research using 14C. Research examining 14C in polar oceans in the context of climate change has led to considerable insight into the marine carbon cycle. The Amundsen Sea, in West Antarctica, is experiencing rapid ice melting because of a warming climate. As found in previous...
Radionuclides present in the marine environment predominantly stem from human activities, notably emanating from nuclear fuel reprocessing plant and nuclear weapons testing. Notably, Sellafield and La Hague facilities in Europe have been significant sources of 129I emissions into the Atlantic Ocean. Subsequently, 129I transported via ocean currents reaching the Canada...
Recent studies indicate that the Arctic is warming up to four times faster than the global ocean. This accelerated warming is partly due to an increased influx of warm Atlantic waters into the Arctic basin. The Santa Anna Trough (SAT) is a strategically important location within the Arctic Ocean, where the two main Atlantic water branches—the Barents Sea Atlantic Waters (BSAW) and the Fram...
