@article{PAR00028732,
  title = {{D}iurnal changes in cloud cover in eastern {G}abon and their impacts on energy balance, light availability, and water demand : a case study of the 2022 dry season},
  author = {{M}agnan, {M}. and {P}hilippon, {N}. and {M}oron, {V}. and {M}ariscal, {A}rmand and {L}iandrat, {O}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}estern central {A}frica is atypical of the equatorial domain as the main dry season is cloudier than the rainy seasons. {T}o understand this cloud cover's diurnal evolution, we set up an infrared camera and acquired measurements of the total cloud cover fraction ({TCF}) and cloud optical depth at {B}ambidie, {G}abon (0 degrees 44'30.5'{S}, 12 degrees 58'12.4'{E}), from {M}ay to {O}ctober 2022. {D}iurnal variations in {TCF} can be summarized into four types, mostly discretized through the timing and duration of clouds clearing in the afternoon [early afternoon clearing ({E}a{C}), late afternoon clearing ({L}a{C}), and clear night ({CN}i)], while one type [no clearing ({N}o{C})] shows overcast conditions all day long. {M}eteorological measurements show that {N}o{C} days record 50 {W} m 22 less shortwave incoming surface radiation, resulting in daytime temperatures 1 degrees {C} lower than the seasonal norm, but 20% more diffuse light and 0.5 mm day21 less {ET}o. {C}onversely, {E}a{C} days record 50 {W} m 22 more shortwave incoming surface radiation, leading to temperatures 1.5 degrees {C} higher than the seasonal norm, but 40% more direct light. {T}he larger water demand (0.5 mm day21 more {ET}o) is partly compensated by more frequent rainfall at nighttime. {T}he satellite estimates of {S}atellite {A}pplication {F}acilities for supporting {N}owcasting and very short-range {F}orecasting ({SAFNWC}) capture the {TCF} variations for most of the four types well. {T}hey confirm that {TCF} is dominated by very low and low clouds whose dissipation in the afternoon and evolution into fractional and cumuliform convective clouds explains the clearings on {E}a{C} and {L}a{C} days. {S}atellite estimates also show that the four types of days extracted at {B}ambidie are representative of a larger-scale cloud cover evolution in western central {A}frica, with a west-east gradient in the timing of afternoon cloud dissipation.},
  keywords = {{C}loud cover ; {R}adiation budgets ; {C}loud retrieval ; {GABON}},
  booktitle = {},
  journal = {{J}ournal of {A}pplied {M}eteorology and {C}limatology},
  volume = {63},
  numero = {12},
  pages = {1445--1461},
  ISSN = {1558-8424},
  year = {2024},
  DOI = {10.1175/jamc-d-23-0225.1},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00028732},
}