TY - JOUR
T1 - A fjord with a land-terminating glacier
T2 - Meltwater, bio-optics, particulate matter, nutrients, phytoplankton species, and primary production in west Greenland
AU - Lund-Hansen, Lars Chresten
AU - Dahllöf, Ingela
AU - Nielsen, Morten Holtegaard
N1 - Publisher Copyright:
© 2023 The Author(s)
PY - 2023/12
Y1 - 2023/12
N2 - Land-terminating glaciers and submarine melting of marine-terminating glaciers are significant features in Arctic regions and are foreseen to become more frequent as marine-terminating glaciers ultimately develop into a land-terminated state. A transition driven by the continuous rise in Arctic air temperatures, and emphasizes the importance of studies of land-terminating glaciers their bio-optical properties and biogeochemistry. Kangerlussuaq in west Greenland with a land-terminating glaciers and was selected for this study. During a research cruise we measured spectral and PAR attenuation, particulate matter concentrations, salinity, nutrient concentrations, Chla, and phytoplankton species composition, along a transect from river outlet to open marine waters. Results showed that surface waters in Kangerlussuaq were strongly influenced by meltwater with low salinities, high particulate matter concentrations, high PAR and spectral light attenuation coefficients, and low nutrient concentrations. Spectral composition was also affected by the particulate matter. PAR photic depths varied between 4 and 9 m dependent on particulate matter concentrations. There was a decrease with distance from outlet in silicate concentrations, and opposite for phosphate, which increased significantly from river outlet to the marine. Phytoplankton species number (42) and diversity were high at the marine station but low (3) in turbid waters dominated by the diatom Skeletonema costatum in high numbers. A meltwater plume covered about 50 % of the Kangerlussuaq at average discharges in early August. Primary production was quantified with a simple model based on light attenuation coefficients, and showed a near exponential decrease in production with increase in attenuation.
AB - Land-terminating glaciers and submarine melting of marine-terminating glaciers are significant features in Arctic regions and are foreseen to become more frequent as marine-terminating glaciers ultimately develop into a land-terminated state. A transition driven by the continuous rise in Arctic air temperatures, and emphasizes the importance of studies of land-terminating glaciers their bio-optical properties and biogeochemistry. Kangerlussuaq in west Greenland with a land-terminating glaciers and was selected for this study. During a research cruise we measured spectral and PAR attenuation, particulate matter concentrations, salinity, nutrient concentrations, Chla, and phytoplankton species composition, along a transect from river outlet to open marine waters. Results showed that surface waters in Kangerlussuaq were strongly influenced by meltwater with low salinities, high particulate matter concentrations, high PAR and spectral light attenuation coefficients, and low nutrient concentrations. Spectral composition was also affected by the particulate matter. PAR photic depths varied between 4 and 9 m dependent on particulate matter concentrations. There was a decrease with distance from outlet in silicate concentrations, and opposite for phosphate, which increased significantly from river outlet to the marine. Phytoplankton species number (42) and diversity were high at the marine station but low (3) in turbid waters dominated by the diatom Skeletonema costatum in high numbers. A meltwater plume covered about 50 % of the Kangerlussuaq at average discharges in early August. Primary production was quantified with a simple model based on light attenuation coefficients, and showed a near exponential decrease in production with increase in attenuation.
KW - Bio-optical properties
KW - Greenland
KW - Land-terminating glacial fjord
KW - Meltwater
KW - Nutrients
KW - Particulate matter
KW - Primary production
UR - http://www.scopus.com/inward/record.url?scp=85163828672&partnerID=8YFLogxK
U2 - 10.1016/j.rsma.2023.103054
DO - 10.1016/j.rsma.2023.103054
M3 - Journal article
AN - SCOPUS:85163828672
SN - 2352-4855
VL - 64
JO - Regional Studies in Marine Science
JF - Regional Studies in Marine Science
M1 - 103054
ER -