@article{fdi:010040716,
  title = {{E}stimating downward long-wave radiation on the {A}ndean {A}ltiplano},
  author = {{L}homme, {J}ean-{P}aul and {V}acher, {J}ean-{J}oinville and {R}ocheteau, {A}lain},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {A}ndean {A}ltiplano is a vast plateau lying at an average altitude of 4000 m above sea level, between {B}olivia and {P}eru, and prone to radiative frost during the cropping season. {S}ince the occurrence of radiative frost is generated by a deficit in long-wave radiation, accurate estimation of downward long-wave radiation is essential in models of frost prediction. {H}owever, most simple formulas tend to significantly overestimate this radiation in clear-sky conditions. {F}rom measurements made during two cropping seasons on two different sites on the {B}olivian {A}ltiplano, it is shown that the downward long-wave radiation can be more accurately estimated by means of an adjusted form of {B}rutsaert's [{B}rutsaert, {W}., 1975. {O}n a derivable formula for long-wave radiation from clear skies. {W}ater {R}esour. {R}es. 11, 742-744] equation, with a modified leading coefficient (7.18 instead of 1.24) multiplied by a cloudiness correction. {T}he lower value of the leading coefficient apparently results from steeper vertical gradients of temperature and humidity in this high-altitude region. {T}he cloud correction takes the form of a linear function of the ratio (s) between the observed magnitude of solar radiation and its clear-sky estimate, expressed as {F}(s) = -0.34s + 1.37. {T}he formula was first calibrated on one measurement site ({C}ondoriri) and then tested on the other site ({I}rpani). {F}or daytime hours, the comparison between estimated and measured values is rather satisfactory. {D}uring nighttime hours the formula yields reasonably good estimates when the value of ratio s (not available at night) is replaced by its mean value calculated the previous day between 14 h and 16 h 30 min. {C}rawford and {D}uchon's [{C}rawford, {T}.{M}., {D}uchon, {C}.{E}., 1999. {A}n improved parameterization for estimating effective atmospheric emissivity for use in calculating daytime downwelling long-wave radiation. {J}. {A}ppl. {M}eteorol. 38, 474-480] cloud correction, based on the same ratio s, proves also to work fairly well under these particular conditions.},
  keywords = {long wave radiation ; {A}ndean {A}ltiplano ; clear sky ; cloud correction},
  booktitle = {},
  journal = {{A}gricultural and {F}orest {M}eteorology},
  volume = {145},
  numero = {3-4},
  pages = {139--148},
  ISSN = {0168-1923},
  year = {2007},
  DOI = {10.1016/j.agrformet.2007.04.007},
  URL = {https://www.documentation.ird.fr/hor/fdi:010040716},
}