In:
Ocean Science, Copernicus GmbH, Vol. 19, No. 2 ( 2023-04-05), p. 403-420
Abstract:
Abstract. The Greenland ice sheet is melting, and the rate of ice
loss has increased 6-fold since the 1980s. At the same time, the Arctic sea
ice extent is decreasing. Meltwater runoff and sea ice reduction both
influence light and nutrient availability in the coastal ocean, with
implications for the timing, distribution, and magnitude of phytoplankton
production. However, the integrated effect of both glacial and sea ice melt
is highly variable in time and space, making it challenging to quantify. In
this study, we evaluate the relative importance of these processes for the
primary productivity of Disko Bay, west Greenland, one of the most important
areas for biodiversity and fisheries around Greenland. We use a
high-resolution 3D coupled hydrodynamic–biogeochemical model for 2004–2018 validated against in situ observations and remote sensing products. The model-estimated net primary production (NPP) varied between 90–147 gC m−2 yr−1 during 2004–2018, a period with variable freshwater discharges
and sea ice cover. NPP correlated negatively with sea ice cover and
positively with freshwater discharge. Freshwater discharge had a strong
local effect within ∼ 25 km of the source-sustaining productive hot
spots during summer. When considering the annual NPP at bay scale, sea ice
cover was the most important controlling factor. In scenarios with no sea
ice in spring, the model predicted a ∼ 30 % increase in annual
production compared to a situation with high sea ice cover. Our study
indicates that decreasing ice cover and more freshwater discharge can work
synergistically and will likely increase primary productivity of the coastal
ocean around Greenland.
Type of Medium:
Online Resource
ISSN:
1812-0792
DOI:
10.5194/os-19-403-2023
DOI:
10.5194/os-19-403-2023-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2023
detail.hit.zdb_id:
2183769-7
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