@article{fdi:010062510,
  title = {{P}hysical controls on {CH}4 emissions from a newly flooded subtropical freshwater hydroelectric reservoir : {N}am {T}heun 2},
  author = {{D}eshmukh, {C}. and {S}erca, {D}. and {D}elon, {C}. and {T}ardif, {R}. and {D}emarty, {M}. and {J}arnot, {C}. and {M}eyerfeld, {Y}. and {C}hanudet, {V}. and {G}uedant, {P}. and {R}ode, {W}. and {D}escloux, {S}. and {G}u{\'e}rin, {F}r{\'e}d{\'e}ric},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n the present study, we measured independently {CH}4 ebullition and diffusion in the footprint of an eddy covariance system ({EC}) measuring {CH}4 emissions in the {N}am {T}heun 2 {R}eservoir, a recently impounded (2008) subtropical hydroelectric reservoir located in the {L}ao {P}eople's {D}emocratic {R}epublic ({PDR}), {S}outheast {A}sia. {T}he {EC} fluxes were very consistent with the sum of the two terms measured independently (diffusive fluxes + ebullition={EC} fluxes), indicating that the {EC} system picked up both diffusive fluxes and ebullition from the reservoir. {W}e showed a diurnal bimodal pattern of {CH}4 emissions anti-correlated with atmospheric pressure. {D}uring daytime, a large atmospheric pressure drop triggers {CH}4 ebullition (up to 100 mmol m(-2) d(-1)), whereas at night, a more moderate peak of {CH}4 emissions was recorded. {A}s a consequence, fluxes during daytime were twice as high as during nighttime. {A}dditionally, more than 4800 discrete measurements of {CH}4 ebullition were performed at a weekly/fortnightly frequency, covering water depths ranging from 0.4 to 16m and various types of flooded ecosystems. {M}ethane ebullition varies significantly seasonally and depends mostly on water level change during the warm dry season, whereas no relationship was observed during the cold dry season. {O}n average, ebullition was 8.5 +/- 10.5 mmol m(-2) d(-1) and ranged from 0 to 201.7 mmol m(-2) d(-1). {A}n artificial neural network ({ANN}) model could explain up to 46% of seasonal variability of ebullition by considering total static pressure (the sum of hydrostatic and atmospheric pressure), variations in the total static pressure, and bottom temperature as controlling factors. {T}his model allowed extrapolation of {CH}4 ebullition on the reservoir scale and performance of gap filling over four years. {O}ur results clearly showed a very high seasonality: 50% of the yearly {CH}4 ebullition occurs within four months of the warm dry season. {O}verall, ebullition contributed 60-80% of total emissions from the surface of the reservoir (disregarding downstream emissions), suggesting that ebullition is a major pathway in young hydroelectric reservoirs in the tropics.},
  keywords = {{LAOS}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {11},
  numero = {15},
  pages = {4251--4269},
  ISSN = {1726-4170},
  year = {2014},
  DOI = {10.5194/bg-11-4251-2014},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062510},
}