@article{fdi:010067619,
  title = {{R}adiative properties of clouds over a tropical {B}olivian glacier : seasonal variations and relationship with regional atmospheric circulation},
  author = {{S}icart, {J}ean-{E}mmanuel and {E}spinoza, {J}. {C}. and {Q}ueno, {L}. and {M}edina, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}t low latitudes, strong seasonal changes in cloud cover and precipitation largely control the mass balance of glaciers. {M}easurements of shortwave and longwave radiation fluxes reaching {Z}ongo glacier, {B}olivia (16 degrees {S}, 5060m asl), were analysed from 2005 to 2013 to investigate cloud radiative properties. {C}loud shortwave attenuation and longwave emission were greater in the wet summer season ({DJF}) than in the dry winter season ({JJA}) probably because most {DJF} clouds were low warm cumulus associated with local convection, whereas {JJA} clouds were frequently altostratus associated with extra-tropical perturbations. {S}olar irradiance was high all year round and cloud radiative forcing on down-welling fluxes was strongly negative, with monthly averages ranging from -60 to -110{W}m(-2) from the dry to the wet season, respectively. {I}n the wet season, high extraterrestrial solar irradiance and low shortwave transmissivity caused very negative cloud forcing despite the high longwave emissivity of convective clouds. {R}eanalysis of wind and geopotential height anomalies and outgoing longwave radiation satellite data were used to characterize the regional atmospheric circulation causing thick cloud covers (10% thickest clouds) during the dry ({JJA}), transition ({SON}), and wet ({DJF}) seasons. {A}round 87% (80%) of cloud events in {JJA} ({SON}) occurred during the incursion of low-level southern wind from southern {S}outh {A}merica to the {B}olivian {A}ndes, which caused 2-3 days of cold surge episodes in the {C}ordillera {R}eal. {A}round 13% of cloudy days in {JJA} were associated with high-level low-pressure conditions over the {C}hilean coast around 45 degrees {S}, including cut-off lows. {I}n {SON}, 20% of cloudy days were associated with summer conditions, characterized by an active {B}olivian {H}igh and moist air advection from the {A}mazon basin. {I}n the wet season, only 46% of thick cloud events were associated with low-level southern wind incursions, the other events being associated with the {S}outh {A}merican {M}onsoon.},
  keywords = {tropics ; cloud ; radiation ; glacier ; atmospheric circulation ; cold surge ; {A}ndes ; {B}olivia ; {BOLIVIE} ; {ANDES}},
  booktitle = {},
  journal = {{I}nternational {J}ournal of {C}limatology},
  volume = {36},
  numero = {8},
  pages = {3116--3128},
  ISSN = {0899-8418},
  year = {2016},
  DOI = {10.1002/joc.4540},
  URL = {https://www.documentation.ird.fr/hor/fdi:010067619},
}