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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3351-3376 |
| Number of pages | 26 |
| Journal | Biogeosciences |
| Volume | 16 |
| Issue number | 17 |
| DOIs | |
| State | Published - Sep 5 2019 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Earth-Surface Processes
Cite this
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. / Manning, Cara C.; Stanley, Rachel H.R.; Nicholson, David P.; Loose, Brice; Lovely, Ann; Schlosser, Peter; Hatcher, Bruce G.
In: Biogeosciences, Vol. 16, No. 17, 05.09.2019, p. 3351-3376.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - 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
AU - Manning, Cara C.
AU - Stanley, Rachel H.R.
AU - Nicholson, David P.
AU - Loose, Brice
AU - Lovely, Ann
AU - Schlosser, Peter
AU - Hatcher, Bruce G.
PY - 2019/9/5
Y1 - 2019/9/5
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85072033469&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85072033469&partnerID=8YFLogxK
U2 - 10.5194/bg-16-3351-2019
DO - 10.5194/bg-16-3351-2019
M3 - Article
AN - SCOPUS:85072033469
VL - 16
SP - 3351
EP - 3376
JO - Biogeosciences
JF - Biogeosciences
SN - 1726-4170
IS - 17
ER -