RU2689839C1 - Method for determining intensity and amount of rainfall - Google Patents

Abstract

FIELD: meteorology.SUBSTANCE: invention relates to meteorology and can be used to determine intensity and amount of rainfall in surface layer of atmosphere. In the period of rainfall precipitation, the beta-radiation flux density is continuously measured at a certain height from the earth's surface. Time of increase of beta radiation flux density to its maximum value is determined. Obtained values are used to calculate intensity and quantity of rainfall in the surface layer of the atmosphere.EFFECT: high accuracy and simplification of determining intensity and quantity of rainfall.1 cl, 1 dwg

Description

The invention relates to meteorology and can be used to determine the intensity of rainfall in the atmospheric surface layer from the measured beta-radiation flux density.

There is a method of determining the intensity and amount of rain [RU 2097798 C1, IPC 6 G01W 1/14, publ. 27.11.1997], which consists in radar sounding of the atmosphere to identify the type of clouds according to known criteria, and in determining the desired precipitation parameters using correlation functions and data of the radar reflectivity of clouds. At least one control zone is distinguished in the study area with an increased probability of precipitation and a precipitation station is placed on it. Using this station, various types of clouds moving over it are used to measure precipitation, while simultaneously conducting radar sounding of cloudiness over the station and finding the levels of radar reflectivity corresponding to the obtained precipitation. The obtained data is used to calibrate the radar station, and, after which radar measurements of precipitation are carried out in a controlled area. The intensity and amount of rainfall are determined respectively from the expressions:

where Z is the reflectivity, dB;

I - precipitation intensity, mm / h (m / s);

Q - the amount of precipitation, mm (m);

A, B, b, c are coefficients depending on the type of clouds and the type of precipitation (weak, strong, heavy rain, etc.).

In this method, for each case of precipitation, it is necessary to determine its coefficients, which depend on the spectrum of droplets, the type and microstructure of precipitation, as well as orographic features. The method is complicated, requires long-term observations in the control area, and also has a large measurement error.

There is a method of determining the intensity of rainfall [RU 2003142 C1, IPC 5 G01W 1/14, publ. 15.11.1993], including n-cycles of measurements, each of which consists in the accumulation of precipitation over time τ _i (i = 1, 2, 3, ..., n), determining the increment m _{i of} their mass and intensity value R _i , mm / h (m / s). Between the cycles of measurements withstand pauses, the duration of each of which is not less than the calming time of the mass meter. The increment value m _{i of the} accumulated mass of precipitation is measured during the corresponding pause. The value of the correction for the transition from the accumulation mode to the pause mode and back is found from the expression:

where S _o - the maximum value of the area of the measured flow of precipitation, m ² ;

t ₁ , t ₂ - time points corresponding to the minimum S (t ₁ ) = 0 and maximum

S (t ₂ ) = S _o values of the area of the inlet opening in the receiver during the transition from accumulation mode to pause mode and vice versa, s;

S (t) is the current value of the inlet area in the precipitation receiver at time t, where t ₁ ≤t≤t ₂ t, the accumulation time and

where δ is the relative error in determining the intensity of precipitation,% (relative units);

Δm is the measurement error of the increment of the mass of precipitation, g (kg);

ρ is the density of water, g / cm ³ (kg / m ³ ).

This way it is impossible to reliably determine the time of the beginning of rain, and the time of accumulation of precipitation in the first cycle is set based on a visual assessment of the meteorological situation. If it rains during non-working hours, visual assessment is not possible. If a small accumulation time is established in the event of high-intensity precipitation, excessive precipitation can flow out of the measuring chamber. And, on the contrary, when establishing a large accumulation time in the first cycle with low-intensity precipitation, it is impossible to reliably determine the time of the start of rain. All of these cases lead to a decrease in the reliability of the measurement result.

а интенсивность дождевых осадков в приземном слое атмосферы определяют из выражения:There is a method of determining the intensity of rainfall in the atmospheric surface layer [RU 2656118 C1, IPC 51 G01W 1/14, publ. 31.05.2018], selected as a prototype, based on the fact that during the period of rainfall, continuous measurements of the gamma-radiation dose rate are made at a height of at least 1 m from the earth's surface with a beat of at least 1 measurement in 60 s, then the time is determined increase t _end dose rate of gamma radiation to its maximum value

and the intensity of rainfall in the surface layer of the atmosphere is determined from the expression:

where I is the intensity of rainfall, m / s;

- измеренное значение мощности дозы гамма-излучения в момент времени t_end, Зв/с;

- the measured value of the dose rate of gamma radiation at time t _end , Sv / s;

с;t _end is the rise time of the gamma radiation dose rate to its maximum value

with;

- измеренное фоновое значение мощности дозы гамма-излучения до начала дождевых осадков, Зв/с;

- the measured background value of the gamma radiation dose rate before the onset of rainfall, Sv / s;

k is the coefficient of absolute washing capacity of rain;

и

- мощности дозы гамма-излучения, создаваемые короткоживущими продуктами распада радона ²¹⁴Pb и ²¹⁴Bi, (Зв/с)/(Бк/м³);

and

- dose rates of gamma radiation generated by short-lived decay products of radon ²¹⁴ Pb and ²¹⁴ Bi, (Sv / s) / (Bq / m ³ );

и

- средние значения объемных активностей короткоживущих продуктов распада радона ²¹⁴Pb и ²¹⁴Bi в приземной атмосфере, Бк/м³.

and

- average values of the volume activities of short-lived decay products of radon ²¹⁴ Pb and ²¹⁴ Bi in the surface atmosphere, Bq / m ³ .

The amount of rainfall is determined by multiplying the intensity at the time of their precipitation.

This method has a limit on the height of measuring the gamma radiation dose rate - not less than 1 m from the earth's surface.

The proposed method for determining the intensity and amount of rainfall from the measured beta-radiation flux density in the surface layer of the atmosphere expands the arsenal of tools of similar purpose.

, а интенсивность и количество дождевых осадков в приземном слое атмосферы определяют из выражений:According to the invention, a method for determining the intensity and amount of rainfall is that, during the period of rainfall, beta-radiation flux density is measured at a height z from the earth's surface, then the rise time t _end beta-flux density is determined to its maximum value

, and the intensity and amount of rainfall in the atmospheric surface layer is determined from the expressions:

where: I - the intensity of rainfall, m / s;

Q - the amount of rainfall, m;

- измеренное на высоте z от земной поверхности значение плотности потока бета-излучения в момент времени t_end, 1/(м²⋅с);

- measured at height z from the earth's surface, the value of the flux density of beta radiation at time t _end , 1 / (m ² ⋅s);

с;t _end - the rise time of the beta-flux density to its maximum value

with;

- измеренное на высоте z от земной поверхности фоновое значение плотности потока бета-излучения до начала дождевых осадков, 1/(м²⋅с);

- measured at a height z from the earth's surface background value of the flux density of beta radiation before the start of rainfall, 1 / (m ² ⋅s);

k is the coefficient of the absolute washing capacity of rain, 1 / m;

и

- плотности потоков бета-излучения на высоте z, создаваемые осажденными на земную поверхность короткоживущими продуктами распада радона ²¹⁴Pb и ²¹⁴Bi, рассчитанные на единичную объемную активность радионуклидов, (1/(м²⋅с))/(Бк/м³);

and

- beta-radiation flux densities at height z created by short-lived radon decay products ²¹⁴ Pb and ²¹⁴ Bi deposited on the earth’s surface, calculated for a single volumetric activity of radionuclides, (1 / (m ² s)) / (Bq / m ³ );

и

- средние значения объемных активностей короткоживущих продуктов распада радона ²¹⁴Pb и ²¹⁴Bi в приземной атмосфере, Бк/м³.

and

- average values of the volume activities of short-lived decay products of radon ²¹⁴ Pb and ²¹⁴ Bi in the surface atmosphere, Bq / m ³ .

R., Chagnon, F., Hoffman, I., Korpach, E.P., Johnson, S., Ungar, R.K., 2009. Increased environmental gamma-ray dose rate during precipitation: a strong correlation with contributing air mass. J. Environ. Radioact. 100, 527-533. EURADOS Report, 1999. Radiation Protection 106, URL: 〈http://ec.europa.eu/energy/nuclear/radiation_protection/doc/publication/rp106.pdf〉]. Другие природные радионуклиды, например, бета-, гамма-излучающие продукты распада торона, практически не влияют на величину мощности дозы гамма-излучения, поскольку их активность намного меньше активности ²¹⁴Pb и ²¹⁴Bi.The beta-flux flux density reaction to precipitation, which manifests itself as anomalous bursts (Fig. 1), was studied theoretically and experimentally [Yakovleva VS, Nagorsky PM, Cherepnev MS, Kondratyeva AG, Ryabkina KS, 2016. the atmospheric β- and γ-radiation. Applied Radiation and Isotopes. 118, 190-195]. The explanation for the increase in beta-radiation flux density during periods of precipitation is leaching of beta, gamma-emitting short-lived decay products of radon ²¹⁴ Pb and ²¹⁴ Bi by rainfall on the earth's surface [Burnett, JL, Croudace, IW, Warwick, R.Е., 2010 Gamma-radiation dose. J. Radiol. Prot. 30, 525-532. Mercier, J.-F., Tracy, BL,

R., Chagnon, F., Hoffman, I., Korpach, EP, Johnson, S., Ungar, RK, 2009. Increased environmental dose during precipitation: a. J. Environ. Radioact. 100, 527-533. EURADOS Report, 1999. Radiation Protection 106, URL: 〈http://ec.europa.eu/energy/nuclear/radiation_protection/doc/publication/rp106.pdf]. Other natural radionuclides, for example, beta, gamma-emitting decay products of toron, practically do not affect the magnitude of the dose rate of gamma radiation, since their activity is much less than the activity of ²¹⁴ Pb and ²¹⁴ Bi.

The rise time of beta-flux density t _end continues from the beginning to the end of precipitation. After the precipitation ends, the beta flux density decreases exponentially to the background value due to radioactive decay of ²¹⁴ Pb and ²¹⁴ Bi.

Thus, the proposed method for determining the intensity and amount of rainfall is: 1) simple and reliable, since it suffices to measure only the beta-radiation flux density, i.e. use only one measuring unit; 2) reliable, because the method is based on well-tested models of ionizing radiation transfer, radionuclides and physical laws, and since the error in determining the intensity of precipitation decreases due to the fact that the time of the beginning of rain is known, which corresponds to the beginning of the increase in beta-radiation flux density.

The method for determining the intensity and amount of rainfall in the atmospheric surface layer from the measured beta-radiation flux density is suitable for both one-time measurements and for long-term automated monitoring of the intensity and amount of rainfall if beta-radiation detection units are used that operate in monitoring mode.

FIG. 1 shows a) - the dynamics of the measured beta-radiation flux density at altitudes of 1 m (curve 1), 10 m (curve 2) and 35 m (curve 3) using the beta-radiation detection unit BDPB-01, b) - intensity dynamics precipitation according to the Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences, Tomsk, obtained using a shuttle precipitation gauge.

To determine the intensity and amount of rainfall, we chose a site located near the Institute for Monitoring Climate and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences in Tomsk.

Using the beta-radiation detection unit BDPB-01 (Atomtech, Belarus) at altitudes of 1 m (curve 1), 10 m (curve 2) and 35 m (curve 3) from the earth's surface, we continuously measured beta radiation flux density during 32 hours (and in Fig. 1). During this period there was a case of rainfall. According to the Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences in Tomsk, obtained using a shuttle precipitation gauge, the rainfall intensity during this time period was 52.1 mm / h (8.68⋅10 ^-4 m / s).

Measured at a height of 1 m from the earth's surface, the background value of the beta-radiation flux density before the start of rainfall was

максимальное значение плотности потока бета-излучения составило

(

Время нарастания t_end плотности потока бета-излучения от фонового до максимального значения составило 21 мин. (1260 с).(

The maximum value of the beta flux density is

(

The rise time t _end of the beta-radiation flux density from the background to the maximum value was 21 minutes. (1260 s).

и

на высоте z=1 м, создаваемые осажденными на земную поверхность короткоживущими продуктами распада радона ²¹⁴Pb и ²¹⁴Bi единичной объемной активности, с использованием программы PCLab [Компьютерная лаборатория (КЛ/PCLab). Свидетельство о государственной регистрации программы ЭВМ №2007615275 от 28.12.2007]. Геометрия и входные данные для моделирования описаны в [Яковлева B.C., Каратаев В.Д., Зукау В.В. Моделирование атмосферных полей γ- и β-излучений, формирующихся почвенными радионуклидами // Вестник КРАУНЦ. Физ.-мат. науки. - 2011. - №1 (2). - С. 64-73]. Рассчитанные значения плотности потоков бета-излучения ²¹⁴Pb и ²¹⁴Bi на высоте 1 м составили, соответственно:With the help of the Monte Carlo method, the values of beta-flux density were determined.

and

at a height of z = 1 m, generated by short-lived decay products of radon ²¹⁴ Pb and ²¹⁴ Bi of unit volumetric activity deposited on the earth surface using the PCLab program [Computer Lab (CL / PCLab). Certificate of state registration of computer program number 20067615275 of December 28, 2007]. Geometry and input data for modeling are described in [Yakovleva VS, Karataev V.D., Zukau V.V. Modeling of atmospheric fields of γ- and β-radiation, formed by soil radionuclides // Vestnik KRAUNC. Phys.-mat. science. - 2011. - №1 (2). - p. 64-73]. The calculated flux densities of beta radiation of ²¹⁴ Pb and ²¹⁴ Bi at a height of 1 m were, respectively:

и

в приземной атмосфере были определены с использованием известной модели переноса радона и короткоживущих продуктов его распада в приземной атмосфере, включающей систему стационарных уравнений, в которых учтены процессы молекулярной диффузии, турбулентного переноса и радиоактивного распада [Яковлева B.C., Вуколов А.В., Нагорский П.М., Гвай И.А., Нейман Д.А. Исследование сдвига радиоактивного равновесия между изотопами радона и продуктами их распада // АНРИ. 2011. №3 (66). С. 43-51]. Для расчетов использовали измеренное с помощью радиометра «Альфарад плюс - РП» (Россия) по прилагаемой к радиометру методике значение плотности потока радона на участке, где производятся измерения плотности потока бета-излучения, равное 10,6 мБк/(м²с). Рассчитанные в программном пакете «Wolfram Mathematica 10.0» средние значения объемных активностей короткоживущих продуктов распада радона ²¹⁴Pb и ²¹⁴Bi в приземной атмосфере составили:Average values of the volumetric activities of short-lived radon decay products

and

in the surface atmosphere were determined using the well-known model of radon transfer and short-lived decay products in the surface atmosphere, including a system of stationary equations that take into account the processes of molecular diffusion, turbulent transfer and radioactive decay [Yakovlev BC, Vukolov AV, Nagorsky P. M., Guay I.A., Neyman D.A. Study of the shift of radioactive equilibrium between radon isotopes and their decay products // ANRI. 2011. № 3 (66). S. 43-51]. For calculations, the measured radon flux density measured at the site where beta-radiation flux densities of 10.6 mBq / (m ² s) are measured using the radiometer “Alfarad plus - RP” (Russia) was used according to the method applied to the radiometer. The average volumetric activities of short-lived decay products of radon ²¹⁴ Pb and ²¹⁴ Bi calculated in the Wolfram Mathematica 10.0 software package in the surface atmosphere were:

The coefficient of the absolute rain-washing capacity k is equal to 36.0, 1 / m (10 ^-5 h / (mm⋅s)) [E.B. Kutner, F. Gisina. Effective capture coefficient of aerosol particles by rain and cloud drops. Proceedings LGMI, vol. 15. - p. 103-117].

We determined the intensity and amount of rainfall in the atmospheric surface layer from expressions (1) and (2), which were, respectively:

The obtained value of the rainfall intensity is in good agreement with the data of the Institute for Monitoring Climate and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences, obtained using a shuttle precipitometer (b in Fig. 1), which indicates the reliability of the proposed method for determining the intensity and amount of rainfall in the atmospheric surface layer .

Claims (11)

The method of determining the intensity and amount of rainfall, including measurement of ionizing radiation, characterized in that during the period of rainfall, continuous measurements of beta-radiation flux density at height z from the earth's surface are made, then the rise time t _end of beta-radiation flux density is determined maximum value

and the intensity and amount of rainfall in the atmospheric surface layer is determined from the expressions:

where I is the intensity of rainfall, m / s; Q - the amount of rainfall, m;

- measured at height z from the earth's surface, the value of the flux density of beta radiation at time t _end , 1 / (m ² ⋅s); t _end - the rise time of the beta-flux density to its maximum value

with;

- measured at a height z from the earth's surface background value of the flux density of beta radiation before the start of rainfall, 1 / (m ² ⋅s); k is the coefficient of the absolute washing capacity of rain, 1 / m;

and

- beta-radiation flux densities at height z created by short-lived radon decay products ²¹⁴ Pb and ²¹⁴ Bi deposited on the earth’s surface, calculated for a single volumetric activity of radionuclides, (1 / (m ² s)) / (Bq / m ³ );

and

- average values of the volume activities of short-lived decay products of radon ²¹⁴ Pb and ²¹⁴ Bi in the surface atmosphere, Bq / m ³ .

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