Molecular and aerosol scattering

The scatter coefficient kr(A) of Rayleigh scattering in dry air is reproduced well by an equation presented by R.E. Bird and C. Riordan [5.38]. This gives the following for the spectral transmissivity with A in /j,m 

Dust and small suspended water droplets form aerosols. They scatter and absorb solar radiant energy, whereby the scattered proportion predominates. The scattering and absorption 

11 John William Strutt, Third Baron of Rayleigh (1842-1919) set up his own physical laboratory at his family seat, Terling Place in Essex, England. In 430 scientific publications he dealt with problems from all areas of classical physics, in particular acoustics, for which he wrote his famous work, The Theory of Sound (1877/78). Together with W. Ramsey he discovered the element Argon (1892-95), for which he was awarded the Nobel prize for Physics in 1904. The chemist W. Ramsey was awarded the Nobel prize for Chemistry in the same year. 

Values between 0.8 and 1.8 are used for the exponent a / varies from /3 = 0 (pure atmosphere) via 0.1 (clear) and 0.2 (cloudy) to 0.3 (very murky atmosphere), see for this [5.34]. The relative optical aerosol mass mfia is generally unknown because of the large fluctuations in the size, distribution and composition of aerosol particles. This is why mrjL from (5.114) is often 

The amount of ozone in the atmosphere is frequently indicated by the height hos of a vertical column of gaseous ozone under standard conditions (tn = 0 °C, pa = 1.01325 bar). This quantity varies seasonally and with latitude it has an average value of around 2.5 mm at the equator, 3.5mm at medium latitudes and up to 4.5 mm at the poles. The amount of ozone has fallen over several years as a result of the discharge of CFCs. At the beginning of spring a reduction up to 20 % of the average value occurs over northern Europe. The hole in the ozone layer over the south pole, which appears in October, leads to a reduction at times of up to 75 %. 

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The two important atmospheric processes are molecular absorption and molecular and aerosol scattering. Absorption by aerosols, both liquid and particulate, is not thought to be important. 

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