~ ss _. ne C be will be made assuming the numerical median diameter to41.85, 1.0, 0.6 and 0.3 microns. The total number of particles re~ quired aloft to reduce solar radiation by 10% when the sun is at the senith is given by the following relations, where it is assumed that the mean solar radiation wave length is 0,57 microns: nxh = ans =—18 s 2-22 = = - - & Buation 9 nx = Number of dust particles of radius, r, in a vertical column of 1 cm“ cross section in the stmosphere, & = Surface area of the earth = 5.1 x 1017 cmé TABLE I PARTICLE DIAMETER IN NICRONS TOTAL NUMBER OF -PARTICLES REQUIRED ALOFT TO REDUCE SOLAR RADIATION BY 0% VALUE CF Ke USED VALUE OF X USED. 1.85. 6.7 x 1074 3 10 1.0 1.7 x 1029 4, 5.5 0.6 5.4 x 102 4 3.3 0.3 6.1 x 1076 1.25 1.65 If it is assumed that the density of dust particles 4s 3 gm/cm3, and that all particles are either spherical (a = b = c) or spheroids, where a = 2b = 3c, then the total number of particles in the atomic cloud from 10 megaton weapons exploded on the surface and subsurface is given in Table II below: ‘TABLE ii 10 Megaton Bomb Total number of Particles in the atomic cloud assuming spherical Subsurface particle distribution of the atomic cloud indicated: exploded on Surface or and spheroidal particles for the different numerical median SPHERICAL PARTICLES WHERE a*bec Surface 1.86 1.0 9.6% Gag Zs Detonation 4x10 2.6x10 1.2x10 9,6x10 Sub-Surface tal Mond "Co 3 aS CF} Cc Detonation 6,6x1024 4,.2x10° a 1.921076 1,6x1027 SPHEROINAL PARTICLE WHERE | a* 2b = 3¢ 1.85 1.0 “ 0,6 0,3 — , 25x10 1.6x10 72x10 58x10 gx1025 2.5x10° 6 1.2x1027 9,3x107?