Heat balances and thermally driven lagoon-ocean exchangeson a tropical coral reef system (Moorea, French Polynesia)
Abstract
© 2015. American Geophysical Union. All Rights Reserved.The role of surface and advective
heat fluxes on buoyancy-driven circulation was examined within a tropical coral reef
system. Measurements of local meteorological conditions as well as water temperature
and velocity were made at six lagoon locations for 2 months during the austral summer.
We found that temperature rather than salinity dominated buoyancy in this system.
The data were used to calculate diurnally phase-averaged thermal balances. A one-dimensional
momentum balance developed for a portion of the lagoon indicates that the diurnal
heating pattern and consistent spatial gradients in surface heat fluxes create a baroclinic
pressure gradient that is dynamically important in driving the observed circulation.
The baroclinic and barotropic pressure gradients make up 90% of the momentum budget
in part of the system; thus, when the baroclinic pressure gradient decreases 20% during
the day due to changes in temperature gradient, this substantially changes the circulation,
with different flow patterns occurring during night and day. Thermal balances computed
across the entire lagoon show that the spatial heating patterns and resulting buoyancy-driven
circulation are important in maintaining a persistent advective export of heat from
the lagoon and for enhancing ocean-lagoon exchange.
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Journal articlePermalink
https://hdl.handle.net/10161/10763Published Version (Please cite this version)
10.1002/2014JC010145Publication Info
Herdman, LMM; Hench, JL; & Monismith, SG (2015). Heat balances and thermally driven lagoon-ocean exchangeson a tropical coral reef
system (Moorea, French Polynesia). Journal of Geophysical Research C: Oceans, 120(2). pp. 1233-1252. 10.1002/2014JC010145. Retrieved from https://hdl.handle.net/10161/10763.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
James Hench
Associate Professor of Oceanography
Research in my lab focuses on fluid dynamics in the coastal ocean and its effects
on transport processes. We use field measurements, computational models, and theoretical
analyses to understand fundamental physical processes in these systems. We also work
extensively on interdisciplinary problems that have a significant physical component
to better understand the effects of water motion on the geochemistry, biology, and
ecology of shallow marine systems. Much of our research is

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