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The distance factor in the relationships between solar radiation and sunshine
Author(s) -
Baker Donald G.,
Skaggs R. H.
Publication year - 1984
Publication title -
journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0196-1748
DOI - 10.1002/joc.3370040203
Subject(s) - sunshine duration , linear regression , radiation , correlation coefficient , linear correlation , atmospheric sciences , constant (computer programming) , degree (music) , meteorology , regression analysis , value (mathematics) , negative correlation , positive correlation , environmental science , statistics , mathematics , geography , physics , optics , relative humidity , computer science , acoustics , programming language , medicine
The effect that distance ( d ) has upon the correlation coefficient ( r ) obtained between paired radiation ( R ) and sunshine ( S ) stations was determined for the North Central region of the United States. Distances between stations varied from 0 to 608 km. In the regression of r against d three features of interest were found. First, the slope of the annual r values with distance is essentially linear from about 60 to 550 km and equals about −0.12/100 km. Secondly, from d = 0 to 60 km, the value of r remains constant at about 0–88, creating a ‘zone of indifference’ due to inherent differences between radiation and sunshine recording instruments and the insensitivity of the latter. Thirdly, beyond about 550 km the slope appears to reach a constant value, which varies with season but is about r = 0–30 on an annual basis. Seasonal and geographical differences in the degree of correlation between r and d are noted and discussed briefly.