TY  - JOUR
A1  - Tanski, George
A1  - Couture, Nicole
A1  - Lantuit, Hugues
A1  - Eulenburg, Antje
A1  - Fritz, Michael
T1  - Eroding permafrost coasts release low amounts of dissolved organic carbon (DOC) from ground ice into the nearshore zone of the Arctic Ocean
JF  - Global biogeochemical cycles
N2  - Ice-rich permafrost coasts in the Arctic are highly sensitive to climate warming and erode at a pace that exceeds the global average. Permafrost coasts deliver vast amounts of organic carbon into the nearshore zone of the Arctic Ocean. Numbers on flux exist for particulate organic carbon (POC) and total or soil organic carbon (TOC, SOC). However, they do not exist for dissolved organic carbon (DOC), which is known to be highly bioavailable. This study aims to estimate DOC stocks in coastal permafrost as well as the annual flux into the ocean. DOC concentrations in ground ice were analyzed along the ice-rich Yukon coast (YC) in the western Canadian Arctic. The annual DOC flux was estimated using available numbers for coast length, cliff height, annual erosion rate, and volumetric ice content in different stratigraphic horizons. Our results showed that DOC concentrations in ground ice range between 0.3 and 347.0mgL(-1) with an estimated stock of 13.63.0gm(-3) along the YC. An annual DOC flux of 54.90.9Mgyr(-1) was computed. These DOC fluxes are low compared to POC and SOC fluxes from coastal erosion or POC and DOC fluxes from Arctic rivers. We conclude that DOC fluxes from permafrost coasts play a secondary role in the Arctic carbon budget. However, this DOC is assumed to be highly bioavailable. We hypothesize that DOC from coastal erosion is important for ecosystems in the Arctic nearshore zones, particularly in summer when river discharge is low, and in areas where rivers are absent.
KW  - Arctic
KW  - permafrost
KW  - coastal erosion
KW  - biogeochemistry
KW  - carbon cycle
Y1  - 2016
U6  - https://doi.org/10.1002/2015GB005337
SN  - 0886-6236
SN  - 1944-9224
VL  - 30
SP  - 1054
EP  - 1068
PB  - American Geophysical Union
CY  - Cambridge
ER  -