TY - JOUR
T1 - Radium inputs into the Arctic Ocean from rivers
T2 - a basin-wide estimate
AU - Bullock, Emma J.
AU - Kipp, Lauren
AU - Moore, Willard
AU - Brown, Kristina
AU - Mann, Paul J.
AU - Vonk, Jorien E.
AU - Zimov, Nikita
AU - Charette, Matthew A.
N1 - Funding information: The authors would like to thank Jessica Dabrowski, Juri Palmtag, Dirk Jong, Lisa Bröder, Kirsi Keskitalo, and the staff of the Northeast Science Station in Cherskiy for their assistance in sample collection in Alaska and Siberia. We would also like to thank Paul Henderson for his work in the field and for his help analyzing samples, and Heather H. Kim for her advice regarding statistical analyses. This study was a broad, collaborative effort that would not have been possible without contributions from numerous funding sources, including the National Science Foundation (NSF-0751525, NSF-1736277, NSF-1458305, NSF-1938873, NSF-2048067, NSF-2134865), the NERC-BMBF project CACOON [NE/R012806/1] (UKRI NERC) and BMBF-03F0806A, and an EU Starting Grant (THAWSOME-676982).
PY - 2022/9
Y1 - 2022/9
N2 - Radium isotopes have been used to trace nutrient, carbon, and trace metal fluxes inputs from ocean margins. However, these approaches require a full accounting of radium sources to the coastal ocean including rivers. Here, we aim to quantify river radium inputs into the Arctic Ocean for the first time for 226Ra and to refine the estimates for 228Ra. Using new and existing data, we find that the estimated combined (dissolved plus desorbed) annual 226Ra and 228Ra fluxes to the Arctic Ocean are [7.0 – 9.4] x 1014 dpm y-1 and [15-18] x 1014 dpm y-1, respectively. Of these totals, 44% and 60% of the river 226Ra and 228Ra, respectively are from suspended sediment desorption, which were estimated from laboratory incubation experiments. Using Ra isotope data from 20 major rivers around the world, we derived global annual 226Ra and 228Ra fluxes of [7.4 – 17] x 1015 and [15 – 27] x 1015 dpm y-1, respectively. As climate change spurs rapid Arctic warming, hydrological cycles are intensifying and coastal ice cover and permafrost are diminishing. These river radium inputs to the Arctic Ocean will serve as a valuable baseline as we attempt to understand the changes that warming temperatures are having on fluxes of biogeochemically important elements to the Arctic coastal zone.
AB - Radium isotopes have been used to trace nutrient, carbon, and trace metal fluxes inputs from ocean margins. However, these approaches require a full accounting of radium sources to the coastal ocean including rivers. Here, we aim to quantify river radium inputs into the Arctic Ocean for the first time for 226Ra and to refine the estimates for 228Ra. Using new and existing data, we find that the estimated combined (dissolved plus desorbed) annual 226Ra and 228Ra fluxes to the Arctic Ocean are [7.0 – 9.4] x 1014 dpm y-1 and [15-18] x 1014 dpm y-1, respectively. Of these totals, 44% and 60% of the river 226Ra and 228Ra, respectively are from suspended sediment desorption, which were estimated from laboratory incubation experiments. Using Ra isotope data from 20 major rivers around the world, we derived global annual 226Ra and 228Ra fluxes of [7.4 – 17] x 1015 and [15 – 27] x 1015 dpm y-1, respectively. As climate change spurs rapid Arctic warming, hydrological cycles are intensifying and coastal ice cover and permafrost are diminishing. These river radium inputs to the Arctic Ocean will serve as a valuable baseline as we attempt to understand the changes that warming temperatures are having on fluxes of biogeochemically important elements to the Arctic coastal zone.
KW - Arctic Ocean
KW - radium isotopes
KW - river fluxes
UR - http://www.scopus.com/inward/record.url?scp=85139102927&partnerID=8YFLogxK
U2 - 10.1029/2022JC018964
DO - 10.1029/2022JC018964
M3 - Article
AN - SCOPUS:85139102927
SN - 2169-8953
VL - 127
JO - Journal of Geophysical Research: Oceans
JF - Journal of Geophysical Research: Oceans
IS - 9
M1 - e2022JC018964
ER -