@article{fdi:010061925,
  title = {{E}nergy fluxes and surface characteristics over a cultivated area in {B}enin : daily and seasonal dynamics},
  author = {{M}amadou, {O}. and {C}ohard, {J}. {M}. and {G}alle, {S}ylvie and {A}wanou, {C}. {N}. and {D}iedhiou, {A}rona and {K}ounouhewa, {B}. and {P}eugeot, {C}hristophe},
  editor = {},
  language = {{ENG}},
  abstract = {{L}atent and sensible heat surface fluxes are key factors of the western {A}frican monsoon dynamics. {H}owever, few long-term observations of these land surface fluxes are available; these are needed to increase understanding of the underlying processes and assess their impacts on the energy and water cycles at the surface-atmosphere interface. {T}his study analyzes turbulent fluxes of one full year, measured with the eddy covariance technique, over a cultivated area in northern {B}enin (western {A}frica). {T}he study site is part of the long-term {AMMA}-{CATCH} ({A}frican {M}onsoon {M}ultidisciplinary {A}nalysis-{C}oupling of the {T}ropical {A}tmosphere and {H}ydrological {C}ycle) hydrological observatory. {T}he flux partitioning was investigated through the evaporative fraction ({EF}) and the {B}owen ratio (beta) at both seasonal and daily scales. {F}inally, the surface conductance ({G}(s)) and the decoupling coefficient ({O}mega) were calculated and compared with specific bare soil or canopy models. {F}our contrasting seasons were identified and characterized by their typical daily energy cycles. {T}he results pointed out the contrasting seasonal variations of sensible and latent heat fluxes due to changing atmospheric and surface conditions. {I}n the dry season, the sensible heat fluxes were largely dominant (beta similar to 10) and a low but significant evapotranspiration was measured ({EF} = 0.08); this was attributed to a few neighboring bushes, possibly fed by the water table. {D}uring the wet season, after the monsoon onset, surface conditions barely affected the evaporative fraction ({EF}), which remained steady ({EF} = 0.75); the latent heat flux was dominant and the {B}owen ration (beta) was about 0.4. {D}uring the dry-to-wet and wet-to-dry transition seasons, both {EF} and beta were highly variable, as they depended on the atmospheric forcing or the response to isolated rains. {A} complete surface-atmosphere decoupling was never observed in 2008 (0 < {O}mega < 0.6), which suggests a systematic mixing of the air within the canopy with the atmospheric surface layer, irrespective of the atmospheric conditions and the vegetation height. {M}odeling approaches showed a good agreement of soil resistance with the {S}akaguchi bare soil model. {C}anopy conductance was also well reproduced with the {B}all-{B}erry stomata model. {W}e showed that the skin surface temperature had a large seasonal and daily amplitude, and played a major role in all the surface processes. {C}onsequently, an accurate modeling of the surface temperature is crucial to represent correctly the energy and water budgets for this region.},
  keywords = {{BENIN}},
  booktitle = {},
  journal = {{H}ydrology and {E}arth {S}ystem {S}ciences},
  volume = {18},
  numero = {3},
  pages = {893--914},
  ISSN = {1027-5606},
  year = {2014},
  DOI = {10.5194/hess-18-893-2014},
  URL = {https://www.documentation.ird.fr/hor/fdi:010061925},
}