@article{d019590a68bd41fb9ef875646bacedb3,
title = "Changes in gross oxygen production, net oxygen production, and air-water gas exchange during seasonal ice melt in Whycocomagh Bay, a Canadian estuary in the Bras d'Or Lake system",
abstract = "Sea ice is an important control on gas exchange and primary production in polar regions. We measured net oxygen production (NOP) and gross oxygen production (GOP) using near-continuous measurements of the O2/Ar gas ratio and discrete measurements of the triple isotopic composition of O2, during the transition from ice-covered to ice-free conditions, in Whycocomagh Bay, an estuary in the Bras d'Or Lake system in Nova Scotia, Canada. The volumetric gross oxygen production was 5.4+2.8-1.6 mmol O2 m-3 d-1, similar at the beginning and end of the time series, and likely peaked at the end of the ice melt period. Net oxygen production displayed more temporal variability and the system was on average net autotrophic during ice melt and net heterotrophic following the ice melt. We performed the first field-based dual tracer release experiment in icecovered water to quantify air-water gas exchange. The gas transfer velocity at > 90% ice cover was 6% of the rate for nearly ice-free conditions. Published studies have shown a wide range of results for gas transfer velocity in the presence of ice, and this study indicates that gas transfer through ice is much slower than the rate of gas transfer through open water. The results also indicate that both primary producers and heterotrophs are active in Whycocomagh Bay during spring while it is covered in ice.",
author = "Manning, {Cara C.} and Stanley, {Rachel H.R.} and Nicholson, {David P.} and Brice Loose and Ann Lovely and Peter Schlosser and Hatcher, {Bruce G.}",
note = "Funding Information: Financial support. This research has been supported by the Woods Hole Oceanographic Institution (Arctic Research Initiative), the National Science Foundation (Office of Polar Programs, grant nos. 1304406 and 1547011), the Natural Sciences and Engineering Research Council of Canada (PGS-D scholarship), and the Canadian Meteorological and Oceanographic Society (Graduate Scholarship). Funding Information: Acknowledgements. We thank Evan Howard (University of Washington) for helpful discussions regarding the GOP calculations. We thank Zoe Sandwith (WHOI) and Dave Woodland (Cape Breton University) for field and laboratory assistance. We also thank the staff of the Little Narrows Ferry Terminal for providing facilities. Rachel H. R. Stanley and Brice Loose received funding from the WHOI Arctic Research Initiative, and Cara C. Manning received graduate scholarships from NSERC and CMOS. Figure 1b–c were modified from an image created by Hanhil (https://commons.wikimedia.org/wiki/File:Canada_ Nova_Scotia_location_map_2.svg, last access: 27 August 2019); “Canada Nova Scotia location map 2” as permitted under the CC-BY-SA 3.0 license, https://creativecommons.org/licenses/by-sa/3.0/ legalcode, last access: 27 August 2019. Publisher Copyright: {\textcopyright} Author(s) 2019.",
year = "2019",
month = sep,
day = "5",
doi = "10.5194/bg-16-3351-2019",
language = "English (US)",
volume = "16",
pages = "3351--3376",
journal = "Biogeosciences",
issn = "1726-4170",
publisher = "European Geosciences Union",
number = "17",
}