The present study describes the effect of clouds （macro-physical parameters） on global solar radia- tion （G）. Data from four years of hourly measurements of G on a horizontal surface were used. These data were col...The present study describes the effect of clouds （macro-physical parameters） on global solar radia- tion （G）. Data from four years of hourly measurements of G on a horizontal surface were used. These data were collected at the South Valley University （SVU） meteoro- logical research station （26.2~N, 32.7~E, 96 m above mean see level. In addition, the cloud modification factor for G （CMF~）was estimated in three cases： high-level, mid-level, and low-level clouds. For every level, the variation of hourly CMF~ as a function of cloud amount （CA） was illustrated. A third-order polynomial between hourly values of CMFc and CA was established. Fur- thermore, the effect of CA in the attenuation of G relative to its corresponding value in cloudless conditions is dis- cussed. For cloud cover 〉 88%, G was reduced by 54%, 34%, and 28% by low-, mid-, and high-level clouds, re- spectively.展开更多
基金supported by the Deanship of Scientific Research-King Saud University
文摘The present study describes the effect of clouds （macro-physical parameters） on global solar radia- tion （G）. Data from four years of hourly measurements of G on a horizontal surface were used. These data were collected at the South Valley University （SVU） meteoro- logical research station （26.2~N, 32.7~E, 96 m above mean see level. In addition, the cloud modification factor for G （CMF~）was estimated in three cases： high-level, mid-level, and low-level clouds. For every level, the variation of hourly CMF~ as a function of cloud amount （CA） was illustrated. A third-order polynomial between hourly values of CMFc and CA was established. Fur- thermore, the effect of CA in the attenuation of G relative to its corresponding value in cloudless conditions is dis- cussed. For cloud cover 〉 88%, G was reduced by 54%, 34%, and 28% by low-, mid-, and high-level clouds, re- spectively.
