Author(s)

Indira Paudel^1,2*, Shabtai Cohen¹, Gerald Stanhill¹

¹Department of Environmental Physics and Irrigation, Institute of Soil, Water and Environmental Sciences, Rishon Le Zion, Israel.
²Department of Forestry and Natural Resources, Purdue University, IN, USA.

An analysis of global radiation measurements and fractional cloud cover observations made in the Israel Meteorological Service’s network of climate stations demonstrated a significant decrease in the transmittance of solar radiation through the atmosphere during the last 60 years. The major cause was the reduced transparency of clouds. Under completely overcast skies with complete cloud cover transmission in the industrialized central coastal region decreased from 0.41 in the mid-20^th century to 0.21 in the first decade of the 21^st century. Under cloudless skies the reduction in the transmission of global radiation was less, from 0.79 to 0.71, and not statistically significant. Similar but somewhat smaller changes were observed in the less industrialized central hill region. Multi-linear analysis showed that since 1970, 61% of the measured decline in global radiation was attributable to changes in fractional cloud cover but only 2% to the marked increase in local fuel combustion; there was no statistically significant interaction between the two parameters.

Cloud Transmission, Fractional Cloud Cover, Dimming and Brightening, Direct and Indirect Aerosol Effects, Fossil Fuel Combustion

Paudel, I. , Cohen, S. and Stanhill, G. (2019) The Role of Clouds in Global Radiation Changes Measured in Israel during the Last Sixty Years. American Journal of Climate Change, 8, 61-76. doi: 10.4236/ajcc.2019.81004.