@misc{10481/71966,
year = {2021},
month = {11},
url = {http://hdl.handle.net/10481/71966},
abstract = {Cooling the surface of freshwater bodies, whose temperatures are above the temperature
of maximum density, can generate differential cooling between shallow and deep regions.
When surface cooling occurs over a long enough period, the thermally induced cross-shore
pressure gradient may drive an overturning circulation, a phenomenon called ‘thermal
siphon’. However, the conditions under which this process begins are not yet fully
characterised. Here, we examine the development of thermal siphons driven by a uniform
loss of heat at the air–water interface in sloping, stratified basins. For a two-dimensional
framework, we derive theoretical time and velocity scales associated with the transition
from Rayleigh–Bénard type convection to a horizontal overturning circulation across
the shallower sloping basin. This transition is characterised by a three-way horizontal
momentum balance, in which the cross-shore pressure gradient balances the inertial terms
before reaching a quasi-steady regime. We performed numerical and field experiments to
test and show the robustness of the analytical scaling, describe the convective regimes and
quantify the cross-shore transport induced by thermal siphons. Our results are relevant
for understanding the nearshore fluid dynamics induced by nighttime or seasonal surface
cooling in lakes and reservoirs.},
organization = {Swiss National Science Foundation (SNSF)
European Commission	175919},
organization = {Physics of Aquatic Systems Laboratory (APHYS), EPFL},
publisher = {Cambridge University Press},
keywords = {Convection in cavities},
keywords = {Buoyancy-driven instability},
keywords = {Topographic effects},
title = {Development of overturning circulation in sloping waterbodies due to surface cooling},
doi = {10.1017/jfm.2021.883},
author = {Ulloa, Hugo N. and Ramón Casañas, Cintia Luz},
}