Analysis of Radiative Observations in Cloudy Atmosphere - Short-Wave Solar Radiation in the Earth's Atmosphere - page 238

7.1.2
Analysis of the Results of Observations in the Middle Latitudes

The observations in the overcast sky were accomplished above the Black Sea
(experiment No. 3: 10th April 1971, the latitude was 44 ◦ N) and the Azov Sea
(experiment No. 4: 5th October 1971, the latitude was 47 ◦ N) within the range
of the CAENEX program. The altitudes of the cloud bottom and top were
0.4-0.85 km in experiment 3 and 0.3-0.85 km in experiment 4. The retrieved
results are presented in Fig. 7.1b and 7.2b and in Table A.12 of Appendix A.
The observations above the Azov Sea were conducted under the conditions of
strong industrial pollution of the atmosphere that is confirmed with the values
ofthevolumeabsorptioncoefficient( 0.12 km −1 ) that are higher than the

values of the observations above the Black Sea (

κ =

κ = 0.05 km −1 ).

Besides, the radiative experiment was accomplished above the ground sur-
face in the suburb of Rustavi city, Georgia (experiment No.5: 5th December
1972, latitude 42 ◦ N). The cloudbottomand topwere at altitudes 3.3-7.2 kmcor-
respondingly. The spectral optical parameters are also presented in Figs. 7.1b
and 7.2b and in Table A.12 of Appendix A. The studied region had a heavy steel
industry with significant air pollution. The cloud was generated just at the
observational site and contained a lot of absorbing black carbon particles. The
cloud volume scattering coefficient in the observations above the land turned
outtobelowerthaninthecaseoftheobservationsabovethesea.

7.1.3
Analysis of the Results of Observations Above Ladoga Lake

The observations were accomplished at latitude 60 ◦ N under overcast condi-
tions (experiment No. 6: 24th September 1972 and experiment No. 7: 20th April
1985). The two-layer cloudiness was observed in experiment 6 with the bot-
toms and tops at altitudes 0.3-2.5 km and 2.0-3.9 km correspondingly. These
results have been obtained by considering the cloud system as a whole. The
cloud bottom and top altitudes in experiment 7 were 0.9-1.4 km.Thespectral
dependence of optical thickness τ 0 and single scattering co-albedo (1 − ω 0 )

ω 0 ) obtained from the data
of experiment 7 shows the conservative scattering at wavelength 0.42

are presented in Figs. 7.1c and 7.2c. Value (1 −

µ .The

oscillations in the curve illustrating the optical thickness in Fig. 7.1c are ex-
plained with the high observational uncertainties, and the smoothed curve is
shown in the same figure. The observational accuracy of experiment 7 is better
than the accuracy of the other cloud experiments. It appeared just during the
data processing: every retrieved point was situated close to the neighbor points
in the spectral curve (Fig. 7.1c), and the uncertainty of the processing were
increasing (the oscillations of spectral curve of τ 0 )onlyinregionsofthemolec-

ular absorption bands due to the break of the applicability region. The values
of volume scattering and absorption coefficients are presented in Table A.12 of
Appendix A.