Function: noun
Date: 1869
: the quantity of radiant solar energy received at the outer layer of the earth's atmosphere that has a mean value of 1370 watts per square meter
Function: noun
Date: 1869
: the quantity of radiant solar energy received at the outer layer of the earth's atmosphere that has a mean value of 1370 watts per square meter
Merriam Webster Collegiate English Dictionary. Merriam Webster - Энциклопедический словарь английского языка. 2012