Appendix 2. Seasonal distribution for solar UV-A intensity (mW/cm2) as measured in Beirut on horizontal (H) and vertical (V) surfaces under prevailing sky conditions.

Appendix 2. Seasonal distribution for solar UV-A intensity (mW/cm²) as measured in Beirut on horizontal (H) and vertical (V) surfaces under prevailing sky conditions.
Season^a	H			V			V/H

Spring (53)	1 329	+/-	547	348	+/-	167	0.308	+/-	0.160
Summer (52)	1 525	+/-	340	348	+/-	112	0.245	+/-	0.110
Autumn (59)	745	+/-	327	592	+/-	275	0.827	+/-	0.323
Winter (48)	690	+/-	370	627	+/-	360	0.870	+/-	0.263
Annual (212)	1 070	+/-	540	480	+/-	277	0.562	+/-	0.368
Note: Values are means +/- standard deviations. ^aSpring, 21 March to 20 June 1985; summer, 21 June to 22 September 1985; autumn, 23 September to 21 December 1985; winter, 22 December 1985 to 28 February 1986; annual, 21 March 1985 to 28 February 1986. The number of observations is given in parentheses.