Climate change is transforming the Arctic Ocean in unprecedented ways which can be most directly observed in the systematic decline in seasonal ice coverage. From the collection and analysis of particulate and dissolved activities of210Po and210Pb from four deepwater superstations, as a part of the US Arctic GEOTRACES cruise during 2015, and in conjunction with previously published data, the temporal and spatial variations in their activities, inventories and residence times are evaluated. The results show that the partitioning of particulate and dissolved phases has changed significantly in the 8 years between 2007 and 2015, while the total210Po and210Pb activities have remained relatively unchanged. Observed total210Po/210Pb activity ratio was less than unity in all deepwater stations, implying disequilibria in the entire water column. From the distribution of total210Po and210Pb in the upper 500 m of all major Arctic Basins, the derived scavenging efficiencies decrease as per the following sequence: Makarov Basin > Gakkel Bridge > Canada Basin Nansen Basin ∼ Amundsen Basin > Alpha Ridge, which is the reverse order of the calculated residence times of210PoT. The scavenging intensities differ between the fully ice‐covered, partially ice‐covered, and no ice‐covered stations, as observed from the differences in the average activities of210Po and210Pb. The average settling velocity of particulate matter based on the210Pb activity is similar to the published values based on230Th, indicating removal mechanism(s) of Th and Pb is (are) similar.
210Bi (
- Award ID(s):
- 1639865
- NSF-PAR ID:
- 10457766
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Limnology and Oceanography: Methods
- Volume:
- 18
- Issue:
- 4
- ISSN:
- 1541-5856
- Page Range / eLocation ID:
- p. 148-162
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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