Journal o/GlacioloD, Vol. 13.- No. 67,1974 THE INFLUENCE OF CLOUDINESS ON THE NET RADIATION BALANCE OF

ABSTRACT. The short-wave and long-wave radiant fluxes measured in the accumulation area of the Greenland ice sheet during a mid-summer period are discussed with respect to their dependence on cloudi-ness. At a cloudiness of 10/10, a mean value of 270 J /cm2 d is obtained for the daily totals of net...

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Main Authors: A Snow Surface, High Albedo, W. Ambach
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
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Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.477.925
http://www.igsoc.org:8080/journal/13/67/igs_journal_vol13_issue067_pg73-84.pdf
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Summary:ABSTRACT. The short-wave and long-wave radiant fluxes measured in the accumulation area of the Greenland ice sheet during a mid-summer period are discussed with respect to their dependence on cloudi-ness. At a cloudiness of 10/10, a mean value of 270 J /cm2 d is obtained for the daily totals of net radiation balance, whereas a mean value of only 75 J /cm2 d is observed at 0 / 10. The energy excess of the net radiation balance with overcast sky is due to the significant influence of the incoming long-wave radiation and the high albedo of the surface (average of84 %). High values of net radiation balance a re therefore correlated with high values of long-wave radiation balance and low values of short-wave radiation balance. RESUME. L'injluence de la nebulositi SlIr le bilan radialif net d'une slIrface de neige a jort albedo. Le flux de rayonnement en ondes courtes et longues, mesure dans la zone d'accumulation de la calotte glaciaire du Groenland pendant une demi-periode estivale est discute dans sa dependance par rapport a la nebulosit<'. Par une couverture nuageuse de 10/10 on obtient une valeur moyenne de 270 J /cm2 d pour le totaljournalier du bilan radiatifnet, alors qu'on observe une valeur moyenne de seulement 75 J /cm2 d a 0/10 de nebulosite. L'excedent energetique du bilan radia tif net sous ciel couvert est dil a I'influence significative du rayonnement incident de grande longueur d'onde et au fort albedo de la surface (en moyenne 84 %). Les valeurs elevees du bilan radiatif net sont done liees aux fortes valeurs du bilan radiatif de gran de longueur d 'onde et aux faibles