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Direct observations of diel biological CO2 fixation on the Scotian Shelf, northwestern Atlantic Ocean
Citation
Thomas, H and Craig, SE and Greenan, BJW and Burt, W and Herndl, GJ and Higginson, S and Salt, L and Shadwick, EH and Urrego-Blanco, J, Direct observations of diel biological CO2 fixation on the Scotian Shelf, northwestern Atlantic Ocean, Biogeosciences, 9, (6) pp. 2301-2309. ISSN 1726-4170 (2012) [Refereed Article]
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Copyright Statement
Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0) http://creativecommons.org/licenses/by/3.0/
DOI: doi:10.5194/bg-9-2301-2012
Abstract
Much of the variability in the surface ocean’s carbon
cycle can be attributed to the availability of sunlight, triggering
surface heat flux and photosynthesis, which in turn
regulate the biogeochemical cycling of carbon over a wide
range of time scales. The critical processes of this carbon cycle
regulation, occurring at time scales of a day or less, however,
have undergone few investigations, most of which have
been limited to time spans of several days to months. Optical
methods have helped to infer short-term biological variability,
but complementing investigations of the oceanic CO2
system are lacking. We employ high-frequency CO2 and optical
observations covering the full seasonal cycle on the Scotian
Shelf, northwestern Atlantic Ocean, in order to unravel
diel periodicity of the surface ocean carbon cycle and its effects
on annual budgets. Significant diel periodicity in the
surface CO2 system occurs only if the water column is sufficiently
stable as observed during seasonal warming. During
that time biological CO2 drawdown, or net community production
(NCP), is delayed for several hours relative to the
onset of photosynthetically available radiation (PAR), due to
diel cycles in chlorophyll a concentration and to grazing. In
summer, NCP decreases by more than 90 %, coinciding with
the seasonal minimum of the mixed layer depth and resulting
in the disappearance of the diel CO2 periodicity in the
surface waters.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | CO2, diel cycles, coastal ocean |
| Research Division: | Earth Sciences |
| Research Group: | Oceanography |
| Research Field: | Chemical oceanography |
| Objective Division: | Environmental Management |
| Objective Group: | Coastal and estuarine systems and management |
| Objective Field: | Measurement and assessment of estuarine water quality |
| UTAS Author: | Shadwick, EH (Dr Elizabeth Shadwick) |
| ID Code: | 78643 |
| Year Published: | 2012 |
| Web of Science® Times Cited: | 8 |
| Deposited By: | Research Division |
| Deposited On: | 2012-07-13 |
| Last Modified: | 2017-10-31 |
| Downloads: | 412 View Download Statistics |
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