AUTHOR=Horikawa Takahito , Nomura Daiki , Kanna Naoya , Fukamachi Yasushi , Sugiyama Shin 

TITLE=Effects of the glacial meltwater supply on carbonate chemistry in Bowdoin Fjord, Northwestern Greenland

JOURNAL=Frontiers in Marine Science

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.873860

DOI=10.3389/fmars.2022.873860

ISSN=2296-7745

ABSTRACT=<p>To understand the effects of the glacial meltwater supply on carbonate chemistry and the air–sea CO<sub>2</sub> flux within the fjord, water samples were collected in Bowdoin Fjord in northwestern Greenland for dissolved inorganic carbon (DIC) concentration, total alkalinity (TA), oxygen isotopic ratio (δ<sup>18</sup>O), and chlorophyll <italic>a</italic> concentration analyses in the summers of 2016 and 2017. The partial pressure of CO<sub>2</sub> (<italic>p</italic>CO<sub>2</sub>) in surface water, calculated from DIC and TA, was less than 200 µatm, and was significantly lower than that in the atmosphere (399 ± 3 µatm). Therefore, surface water of the fjord acts as sink for CO<sub>2</sub> in the atmosphere (–4.9 ± 0.7 mmol m<sup>–2</sup> d<sup>–1</sup>). To evaluate the effects of freshwater and land-derived substances by glacial meltwater on <italic>p</italic>CO<sub>2</sub> in the fjord, we calculated the changes of <italic>p</italic>CO<sub>2</sub> in salinity and carbonate chemistry that would result from the inflow of glacial meltwater into the fjord. The calculated <italic>p</italic>CO<sub>2</sub> was high near the calving front, where the contribution of glacier meltwater was significant. Examination of the relationship between salinity-normalized DIC and TA, which was considered DIC and TA input from the land, suggested that the land-derived high <italic>p</italic>CO<sub>2</sub> freshwater affected mainly by the remineralization of the organic matter by bacterial activity was supplied to the Bowdoin Fjord.</p>