@article{PAR00001199,
  title = {{M}icroclimates of l'{A}ven d'{O}rgnac and other {F}rench limestone caves ({C}hauvet, {E}sparros, {M}arsoulas)},
  author = {{B}ourges, {F}. and {G}enthon, {P}ierre and {M}angin, {A}. and {D}'{H}ulst, {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e assess the aerodynamics of the atmosphere in some limestone caves using a 5-year monitoring of the {A}ven d'{O}rgnac system, shorter thermal vertical profiling experiments, and comparison with the time series from other {F}rench caves. {I}n the first rooms. located under the {A}ven opening, our records indicate, for each year, a succession of a summer regime characterized by stable parameters (except for the perturbations introduced by tourist visits) and a winter regime, in which the inner air temperature drops and is highly correlated with that outside. {A}tmospheric composition suggests that during the winter regime the cave is ventilated by the outside air. {W}e show that the onset of the winter regime is governed by a thermo-convective instability involving the inflow of the outside cold and dense air. {A}tmospheric temperature and composition allow us to follow the stepwise progression of the winter regime toward the adjacent rooms. {I}n the {S}alle {P}lane ({SP}), a far room of the {O}rgnac-{I}ssirac karstic system, in which the winter regime has never been observed, the air temperature is extremely homogeneous and steady, and is characterized by a half-daily signal of amplitude less than 0.03 degrees {C}, which is correlated with the derivative of pressure versus time. {T}his correlation, which is also observed in various other confined caves, may be explained by pressure-induced temperature changes relaxed in less than 1 h by thermal exchanges with a large volume of rock whose temperature is assumed to be constant. {T}he various microclimates of karstic cave systems should be taken into account for the conservation of the caves open to tourists and for the interpretation of growth laminae of speleothems. {C}opyright ({C}) 2006 {R}oyal {M}eteorological {S}ociety.},
  keywords = {cave ; cave management ; microclimate ; thermo convection ; confinement ; physical mechanism ; {F}rance},
  booktitle = {},
  journal = {{I}nternational {J}ournal of {C}limatology},
  volume = {26},
  numero = {12},
  pages = {1651--1670},
  ISSN = {0899-8418},
  year = {2006},
  DOI = {10.1002/joc.1327},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00001199},
}