A study was conducted on the relationship of the attenuation coefficient of optical radiation by midges with the meteorological parameters of the atmosphere for the summer conditions of 2018 in Western Siberia. It is shown that the maximum values of the coefficient of attenuation of radiation by the midges are observed at the values of vertical turbulent heat flow from 0 to 60 W/m2, air temperature more than 5-7 C and relative air humidity from 30 to 85%. Minimum values of the coefficient of attenuation of radiation by the midges are observed at values of vertical turbulent heat flow more than 100 W/m2, as well as at negative values of vertical turbulent heat flow, air temperature less than 20 С and relative air humidity more than 60-70%.
The second version of one-parameter model of spectral course of aerosol attenuation coefficient for surface atmosphere layer is proposed. The input parameter of the model is meteorological range of visibility (Sm). The model allows calculating aerosol attenuation coefficients in the spectrum region of 0.44-12 μm at Sm ≥15 km. It is shown that the difference between model calculations and average values of experimental data does not exceed 0.02 km-1.
Model of spectral course of aerosol attenuation coefficient is obtained on the basis of experimental data obtained in arid zone of Kazakhstan. The input parameter of the model is meteorological range of visibility. The model allows calculating aerosol attenuation coefficients for the surface layer of the atmosphere in the range of 0.4-12 μm at meteorological range of visibility more than 20 km.
Angstrom formula parameters for spring conditions of an arid zone of Kazakhstan are received. Values of the Angstrom indicator changes from 0.6 to 3.6, and its average equals 2. Hourly average values of the Angstrom indicator are in range of 1.7÷2.3. The value of the Angstrom indicator increases with growth of temperature. And the inclination coefficient in this dependence equals 0.073 on 1°C. It is shown that the Angstrom indicator decreases with growth of the aerosol extinction coefficient for submicron fraction of particles. The maximum hourly average values of the Angstrom indicator are observed in morning and day time, the minimum values - in evening and night time.
The research of radiation extinction coefficient due to midges (RECM) for background conditions of Western Siberia was conducted from August 19 to September 20, 2017. For this autumn period, assessment of average RECM value was 0.038 km-1. In the daily course of RECM two maxima are revealed: the first insignificant maximum falls on 9 o'clock in the morning, the second considerable day maximum - on 15-16 hours.
Midges contribution estimates to extinction of optical radiation for background conditions of summer of Western Siberia are received. The midges represent live organisms the sizes some millimeters, and include a gnat, a midge, a wood louse, a mosquito and a gadfly. From July 24 to August 13, 2014 the coefficient extinction of midges changed from 0 to 0.14 km-1, and its average value made 0.065 km-1. The daily course extinction coefficient of midges of has the pronounced morning maximum falling on 8 hours and an indistinct evening minimum - for 19 hours. For the received data file, probability of difference of their average values at 8 and 19 hours by t-criterion of Student made 96%.
Comparison of four aerosol models is carried out: two one-parameter models for a ground layer of the arid zone of Kazakhstan, two-parameter model for horizontal paths and two-parameter model for horizontal and slant paths. It is shown that the models obtained using the new methods for construction of linear regression and separation of the components allow physically correct retrieval of not only the values of the aerosol extinction coefficients, but also their root mean square deviations.
One-parameter models of spring, summer and autumn hazes are proposed for calculation of the aerosol extinction coefficients in the wavelength range of 0.4-12 μm in the near-ground layer of the atmosphere in arid zone. Input parameter of models is the value of the aerosol extinction coefficient at one wavelength in visible or IR spectral range.
A new method of separating the extinction coefficients into two components with regard to random errors of measured
characteristics is suggested. The method gives stable and physically correct regression coefficients irrespective of the
data array used.
Three improved methods for correction ofthe aerosol optical thickness of the atmosphere are presented. The first method
provides for obtaining the absolute values AOT or their relative spectral behavior in some wavelength ranges. The
method enables to find and exclude systematic errors in AOT. The second method requires knowing the absolute value
of AOT in the only wavelength range. The values AOT in other wavelength ranges are corrected. The third method is
used at complete absence of the absolute values or the relative spectral behavior of AOT. It is called "the method of zero
point". This method suggested equating with zero the minimum value of AOT in one of the wavelength ranges. In
contrast to the methods suggested earlier, where the orthogonal rms regression was used for determining the relation
between different ranges of the spectrum of AOT, new methods use the generalized formula of linear regression obtained
taking into account the random errors in the attracted data.
The generalized formula is presented allowing to obtain the regression coefficients of the linear equation Y=K0+K1X for the general case, when the scatter of points in the correlation diagram of the values X and Y has been caused by both their random errors of measurements and uncontrolled physical factors. All knows formulas for the regression coefficients are the partial cases of the obtained formula. The ways are proposed and the formulas for the regression coefficients are the partial cases of the obtained formula. The ways are proposed and the formulas are presented for estimating the rms errors of the measured values involving in the formula for calculating the regression coefficients from the experiments data. It is shown that the generalized formula makes it possible to obtain the stable, reliable and physically correct one-parameter models of the aerosol extinction. The obtained formula is interesting for the specialists in processing experimental data and can be used for their correct physical interpretation independently of the field of knowledge.
The paper analyzes the effect of clouds on the spectral dependence of the effective height of the aerosol atmosphere. It is shown that the presence of clouds can change the spectral dependence of the effective atmospheric height, namely, thin cloudiness leads to the increase of the effective atmospheric height in the 1-12 μm spectral region, while thicker one increases it in the 0.4-12 μm region.
Model estimates of the effective heights of the atmosphere for the aerosol extinction coefficients and their components in the range 1.07 to 12 μm, where there are no experimental data, are obtained on the basis of simultaneous measurements of the atmospheric trasparency on horizontal and slant paths [13]. It is shown that the mean value of the effective height of the atmosphere for the aerosol extinction coefficient in the wavelength range 0.44 to 12 μm decreases from 1km in visible range to 0.2-0.3km in the range of "transparency window" of the atmosphere 8-12 μm.
The results are compared of investigation of the continuous extinction of visible and IR radiation and the continuum absorption by water vapor in the wavelength range 10.6 micrometer obtained both in field experiment and laboratory chamber. The reliability is confirmed of the results of investigation of the continuous extinction of optical visible and IR radiation that non-linearly depends on absolute humidity of air. The possible reasons are considered leading to the increase of minimum values of the extinction coefficients as absolute humidity increases. One can conclude based on the analysis that the physical reason of the continuous absorption can be absorption by fine aerosol that does not scatter radiation in visible wavelength range.
In the paper we suggest an empirical model for calculation of aerosol extinction of 0.4 - 12 micrometers wavelength radiation in the near-ground atmospheric layer from measured values of extinction coefficient at two visible wavelengths. The performance of the model under different meteorological conditions is tested. This model is shown to satisfactorily describe the experimental and calculated models of aerosol extinction for different climatic zones and most optical weather types (hazes, fog hazes, haze with drizzle, haze with incessant rain, haze with snow or graupel, ice fog).
This paper deals with the problem of interaction between the optical and electrical parameters of atmosphere. At present the interaction not investigated experimental enough. The results of several series of experiments are presented. The experiments in the artificial media camera; the experiments with the nephelometery installation; the experiments on the measurement of spectral transparency of natural atmosphere by the base method is considered as well. The experimental results allowed us to note the existence of the electro optic ratio. The special conditions for observing the above ratio are discussed.
Based on field data on spectral atmospheric transmission along the extended near-ground paths in an arid zone and in a region of West Siberia, excess continuous absorption of radiation in the 0.44-11.5 micrometers wavelength region has been revealed, which nonlinearly depends on the absolute air humidity. Its value, under assumption of quadratic dependence on absolute air humidity, is about 1000-1450 g -2cm5, far in excess of the continuous absorption by water vapor. The character of its spectral dependence suggests that it is related to the finely dispersed soot aerosol. The absorption coefficients obtained on the near-ground and slant paths are compared. The comparison made shows quite satisfactory agreement between them. The presence of the finely dispersed aerosol in the atmosphere is considered one of the important factors causing the anomalous absorption of optical radiation by clouds.
In this paper we discuss statistical properties of aerosol properties of aerosol extinction of visible and IR radiation from field measurements of spectral transmission of the atmosphere along a horizontal path. The measurements have been carried out in winter under three different types of optical weather (haze, ice mist, and snowfall). We also compare in this paper the spectral behavior of the aerosol extinction coefficients measured in Tomsk and near Moscow.
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