TY - JOUR
T1 - Learning from the past
T2 - Impact of the Arctic Oscillation on sea ice and marine productivity off northwest Greenland over the last 9,000 years
AU - Limoges, Audrey
AU - Weckström, Kaarina
AU - Ribeiro, Sofia
AU - Georgiadis, Eleanor
AU - Hansen, Katrine E.
AU - Martinez, Philippe
AU - Seidenkrantz, Marit Solveig
AU - Giraudeau, Jacques
AU - Crosta, Xavier
AU - Massé, Guillaume
N1 - Publisher Copyright:
© 2020 The Authors. Global Change Biology published by John Wiley & Sons Ltd
PY - 2020/12
Y1 - 2020/12
N2 - Climate warming is rapidly reshaping the Arctic cryosphere and ocean conditions, with consequences for sea ice and pelagic productivity patterns affecting the entire marine food web. To predict how ongoing changes will impact Arctic marine ecosystems, concerted effort from various disciplines is required. Here, we contribute multi-decadal reconstructions of changes in diatom production and sea-ice conditions in relation to Holocene climate and ocean conditions off northwest Greenland. Our multiproxy study includes diatoms, sea-ice biomarkers (IP25 and HBI III) and geochemical tracers (TOC [total organic carbon], TOC:TN [total nitrogen], δ13C, δ15N) from a sediment core record spanning the last c. 9,000 years. Our results suggest that the balance between the outflow of polar water from the Arctic, and input of Atlantic water from the Irminger Current into the West Greenland Current is a key factor in controlling sea-ice conditions, and both diatom phenology and production in northeastern Baffin Bay. Our proxy record notably shows that changes in sea-surface conditions initially forced by Neoglacial cooling were dynamically amplified by the shift in the dominant phase of the Arctic Oscillation (AO) mode that occurred at c. 3,000 yr BP, and caused drastic changes in community composition and a decline in diatom production at the study site. In the future, with projected dominant-positive AO conditions favored by Arctic warming, increased water column stratification may counteract the positive effect of a longer open-water growth season and negatively impact diatom production.
AB - Climate warming is rapidly reshaping the Arctic cryosphere and ocean conditions, with consequences for sea ice and pelagic productivity patterns affecting the entire marine food web. To predict how ongoing changes will impact Arctic marine ecosystems, concerted effort from various disciplines is required. Here, we contribute multi-decadal reconstructions of changes in diatom production and sea-ice conditions in relation to Holocene climate and ocean conditions off northwest Greenland. Our multiproxy study includes diatoms, sea-ice biomarkers (IP25 and HBI III) and geochemical tracers (TOC [total organic carbon], TOC:TN [total nitrogen], δ13C, δ15N) from a sediment core record spanning the last c. 9,000 years. Our results suggest that the balance between the outflow of polar water from the Arctic, and input of Atlantic water from the Irminger Current into the West Greenland Current is a key factor in controlling sea-ice conditions, and both diatom phenology and production in northeastern Baffin Bay. Our proxy record notably shows that changes in sea-surface conditions initially forced by Neoglacial cooling were dynamically amplified by the shift in the dominant phase of the Arctic Oscillation (AO) mode that occurred at c. 3,000 yr BP, and caused drastic changes in community composition and a decline in diatom production at the study site. In the future, with projected dominant-positive AO conditions favored by Arctic warming, increased water column stratification may counteract the positive effect of a longer open-water growth season and negatively impact diatom production.
KW - Arctic Oscillation
KW - Baffin Bay
KW - climate change
KW - diatoms
KW - highly branched isoprenoid (HBI) biomarkers
KW - marine sediment
KW - paleoceanography
KW - phytoplankton
UR - http://www.scopus.com/inward/record.url?scp=85092400844&partnerID=8YFLogxK
U2 - 10.1111/gcb.15334
DO - 10.1111/gcb.15334
M3 - Article
C2 - 32885894
AN - SCOPUS:85092400844
VL - 26
SP - 6767
EP - 6786
JO - Global Change Biology
JF - Global Change Biology
SN - 1354-1013
IS - 12
ER -