Research And Application Of Hard Cosmic Ray Flux For Forecasting Meteorological Conditions ; Kietosios kosminės spinduliuotės tyrimas ir taikymas meteorologiniams procesams prognozuoti
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VILNIUS GEDIMINAS TECHNICAL UNIVERSITY Jovita DAMAUSKAITĖ RESEARCH AND APPLICATION OF HARD COSMIC RAY FLUX FOR FORECASTING METEOROLOGICAL CONDITIONS SUMMARY OF DOCTORAL DISSERTATION TECHNOLOGICAL SCIENCES, ENVIRONMENTAL ENGINEERING (04T) Vilnius 2010 Doctoral dissertation was prepared at Vilnius Gediminas Technical University in 2006–2010. Scientific Supervisor Prof Dr Habil Dmitrijus STYRO (Vilnius Gediminas Technical University, Technological Sciences, Environmental Engineering – 04T). Consultant Prof Dr Jonas KLEIZA (Vilnius Gediminas Technical University, Physical Sciences, Mathematics – 01P). The dissertation is being defended at the Council of Scientific Field of Environmental Engineering at Vilnius Gediminas Technical University: Chairman Prof Dr Habil Pranas BALTRĖNAS (Vilnius Gediminas Technical University, Technological Sciences, Environmental Engineering – 04T). Members: Prof Dr Arūnas BUKANTIS (Vilnius University, Physical sciences, Geography – 06P), Prof Dr Habil Donatas BUTKUS (Vilnius Gediminas Technical University, Technological Sciences, Environmental Engineering – 04T), Dr Vidmantas ULEVIČIUS (State research institute Center for Physical Sciences and Technology, Physical Sciences, Physics – 02P), Prof Dr Habil Petras VAITIEKŪNAS (Vilnius Gediminas Technical University, Technological Sciences, Environmental Engineering – 04T).
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| Publié par | vilnius_gediminas_technical_university |
| Publié le | 01 janvier 2010 |
| Nombre de lectures | 28 |
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VILNIUS GEDIMINAS TECHNICAL UNIVERSITY
Jovita DAMAUSKAIT
RESEARCH AND APPLICATION OF HARD COSMIC RAY FLUX FOR FORECASTING METEOROLOGICAL CONDITIONS
SUMMARY OF DOCTORAL DISSERTATION
TECHNOLOGICAL SCIENCES, ENVIRONMENTAL ENGINEERING (04T)
Vilnius
2010
Doctoral dissertation was prepared at Vilnius Gediminas Technical University in 2006–2010. Scientific Supervisor Prof Dr Habil Dmitrijus STYRO (Vilnius Gediminas Technical University, Technological Sciences, Environmental Engineering – 04T). Consultant Prof Dr Jonas KLEIZA(Vilnius Gediminas Technical University, Physical Sciences, Mathematics – 01P). The dissertation is being defended at the Council of Scientific Field of Environmental Engineering at Vilnius Gediminas Technical University: Chairman Prof Dr Habil Pranas BALTRNAS (Vilnius Gediminas Technical University, Technological Sciences, Environmental Engineering – 04T).Members: Prof Dr Arnas BUKANTIS University, Physical sciences, (Vilnius Geography – 06P), Prof Dr Habil Donatas BUTKUS (Vilnius Gediminas Technical University, Technological Sciences, Environmental Engineering – 04T), Dr Vidmantas ULEVIIUS(State research institute Center for Physical Sciences and Technology, Physical Sciences, Physics – 02P), Prof Dr Habil Petras VAITIEKNAS (Vilnius Gediminas Technical University, Technological Sciences, Environmental Engineering – 04T). Opponents: Assoc Prof Dr Rasel GIRGŽDIEN(Vilnius Gediminas Technical University, Technological Sciences, Environmental Engineering – 04T), Prof Dr Habil Jonas MAŽEIKA(Nature research center, Technological Sciences, Environmental Engineering – 04T). The dissertation will be defended at the public meeting of the Council of Scientific Field of Environmental Engineering in the Senate Hall of Vilnius Gediminas Technical University at 1 p. m. on 10 December 2010. Address: Saultekio al. 11, LT-10223 Vilnius, Lithuania. Tel.: +370 5 274 4952, +370 5 274 4956; fax +370 5 270 0112; e-mail: doktor@vgtu.lt The summary of the doctoral dissertation was distributed on 9 November 2010. A copy of the doctoral dissertation is available for review at the Library of Vilnius Gediminas Technical University (Saultekio al. 14, LT-10223 Vilnius, Lithuania). © Jovita Damauskait, 2010
VILNIAUS GEDIMINO TECHNIKOS UNIVERSITETAS
Jovita DAMAUSKAIT
KIETOSIOS KOSMINS SPINDULIUOTS TYRIMAS IR TAIKYMAS METEOROLOGINIAMS PROCESAMS PROGNOZUOTI
DAKTARO DISERTACIJOS SANTRAUKA
TECHNOLOGIJOS MOKSLAI, APLINKOS INŽINERIJA IR KRAŠTOTVARKA (04T)
Vilnius
2010
Disertacija rengta 2006–2010 metais Vilniaus Gedimino technikos universitete. Mokslinis vadovas prof. habil. dr. Dmitrijus STYRO (Vilniaus Gedimino technikos universitetas, technologijos mokslai, aplinkos inžinerija ir kraštotvarka – 04T). Konsultantas prof. dr. Jonas KLEIZA(Vilniaus Gedimino technikos universitetas, fiziniai mokslai, matematika – 01P).Disertacija ginama Vilniaus Gedimino technikos universiteto Aplinkos inžinerijos ir kraštotvarkos mokslo krypties taryboje: Pirmininkas prof. habil. dr. Pranas BALTRNAS Gedimino technikos (Vilniaus universitetas, technologijos mokslai, aplinkos inžinerija ir kraštotvarka – 04T). Nariai: prof. dr. Arnas BUKANTIS(Vilniaus universitetas, fiziniai mokslai, geografija – 06P), prof. habil. dr. Donatas BUTKUS Gedimino technikos (Vilniaus universitetas, technologijos mokslai, aplinkos inžinerija ir kraštotvarka 04T), – dr. Vidmantas ULEVIIUS(Valstybinis mokslinityriminstitutas Fiziniir technologijos mokslcentras, fiziniai mokslai, fizika – 02P), prof. habil. dr. Petras VAITIEKNAS (Vilniaus Gedimino technikos universitetas, technologijos mokslai, aplinkos inžinerija ir kraštotvarka – 04T). Oponentai: doc. dr. Rasel GIRGŽDIEN(Vilniaus Gedimino technikos universitetas, technologijos mokslai, aplinkos inžinerija ir kraštotvarka – 04T), prof. habil. dr. Jonas MAŽEIKA (Gamtos tyrim technologijos centras, mokslai, aplinkos inžinerija ir kraštotvarka – 04T). Disertacija bus ginama viešame Aplinkos inžinerijos ir kraštotvarkos mokslo krypties tarybos posdyje 2010 m. gruodžio 10 d. 13 val. Vilniaus Gedimino technikos universiteto senato posdžisalje. Adresas: Saultekio al. 11, LT-10223 Vilnius, Lietuva. Tel.: (8 5) 274 4952, (8 5) 274 4956; faksas (8 5) 270 0112; el. paštas doktor@vgtu.lt Disertacijos santrauka išsiuntinta 2010 m. lapkriio 9 d. Disertacij perži galimarti Vilniaus Gedimino technikos universiteto bibliotekoje (Saultekio al. 14, LT-10223 Vilnius, Lietuva). VGTU leidyklos „Technika“ 1822-M mokslo literatros knyga. © Jovita Damauskait, 2010
Introduction Formulation of the problemAn important factor affecting the terrestrial environment is the flux of cosmic rays permanently impinging on the Earth. Due to inevitable interaction with atmospheric gas atoms, primary cosmic particles are not able to penetrate through the Earth’s atmosphere. Therefore, only secondary particles are detected near the Earth’s surface, and most of them consist of muons. The cosmic ray flux is modulated by several processes. Variations of the cosmic ray flux are caused not only by solar activity but also by the changes in the geomagnetic field and meteorological processes. Muon flux variations are caused by the instability of the geomagnetic field and they may be an indirect prognostic indicator of atmospheric pressure changes. It is important to discover the influence of meteorological phenomenon on the intensity of cosmic rays near the surface of the ground. However, the changes in the pattern of cosmic rays can be an indication of a change in atmospheric pressure. It follows that cosmic rays may supplement meteorological information for forecasting the weather. The topicality of the thesis Cosmic rays have long been an object of interest and investigation for scientists. Firstly, cosmic rays are the nuclei of atoms having high energy. Secondly, the origin of high energy cosmic rays is the Galaxy and they are the main source of primary cosmic rays. Data analysis of cosmic rays variations in the upper layers of the atmosphere and at the ground can be used for research a variety of topical issues of modern science. In some cases, cosmic rays directly affect some events, for example, navigation, radiation damage to people in open space, ozone depletion. In other cases, cosmic rays indirectly affect events, for example, weather and climatology, clinical pathology, level of geomagnetic field. Therefore, it is necessary to observe and evaluate hard cosmic ray flux variations while forecasting the changes in atmospheric pressure. The object of the research The object of the research is hard cosmic rays influence on atmospheric pressure changes. The aim of the work– to investigate the changes of hard cosmic rays in interval of energies 1.2–1.6 MeV and atmospheric pressure near the Earth’s
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surface and to estimate for predicting meteorological phenomena (cyclones and anticyclones) according to the variations of hard cosmic ray flux.The tasks of the work 1.cosmic ray changes in interval of energies 1.2–1.6 MeVTo analyze near the Earth’s surface. 2.To estimate the variations of hard cosmic ray flux. 3.To estimate the variations of atmospheric pressure. 4.To propose empirical criteria of cosmic ray change which will allow to predict the changes in atmospheric pressure. 5.To make numerical algorithms for simulation of muon scattering in the atmosphere.The research methodologyApplied research methods: gamma scintillation method, which records gamma quanta and the muons after Compton scattering in lead layers, descriptive statistics, correlation and linear regression methods. Forecasting atmospheric pressure changes according by variations of hard cosmic ray flux the empirical criteria is used. The muon scattering in the atmosphere using numerical algorithms is estimated. Scientific novelty of the researchComplex experimental and theoretical investigations of hard cosmic ray flux changes near the surface of the ground. Assessment and prognosis of connection between hard cosmic ray flux and atmospheric pressure changes. Numerical simulation of atmospheric effect of muon scattering. Practical value The results obtained allow to predict the changes of atmospheric processes which are related to forecasting meteorological situations. Research results will be useful to assess and predict changes in atmospheric pressure, whereas the applied method complements the synoptic method further information in predicting changes in atmospheric pressure. Thesis propositions1.Cosmic ray intensity in interval of energies 1.2–1.6 MeV near the surface of the ground varies due to the external geophysical processes. 2.A statistically close relationship exists between hard cosmic ray flux and atmospheric pressure – correlation dependence.
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3.Hard cosmic ray flux changes allow to forecast short-term the changes in atmospheric pressure. 4.There is a mathematical description of the connection between atmospheric effects and muon scattering. The scope of the scientific work. scientific work consists of the The introduction, four main chapters, general conclusions and recommendations, list of references, list of the author’s publications and four annexes. The total scope of the dissertation is 115 pages, 50 pictures, 18 tables. 146 sources of literature were cited in the thesis. The results of the thesis are published in 9 publications. The results were presented in 2 international and 7 national conferences. The introduction chapter considers the investigated problem and the importance of the thesis, formulates the purpose and tasks of the thesis, and describes the scientific novelty of the research and thesis statements. Finally, the author’s publications on the thesis topic as well as the scope of the thesis are presented. Chapter 1 is intended for the review of literature. The chapter presents the review of the physical nature of cosmic rays and their scattering in the atmosphere and discusses the influence of the solar activity and geomagnetic field on cosmic rays near the surface of the ground. In Chapter 2 the method and the device for measuring cosmic rays as well as the method of measuring atmospheric pressure are described. Also proposes a methodology for the prognosis of atmospheric pressure decreases and increases according to hard cosmic ray flux. Chapter 3 describes the results of the experimental investigation using descriptive statistics, correlation and regression analysis. This chapter presents a detailed discussion of the results obtained by the experimental investigation. In chapter 4 the mathematical model that allows to estimate the connection between muon flux and atmospheric pressure and temperature effects is described. 1. Cosmic rays and their scattering in the atmosphere Primary cosmic rays mainly consist of protons. When they are incident into the atmosphere they destroy the atmospheric nuclei by colliding with them to produce nucleons and various mesons. These particles produced in the atmosphere and called secondary cosmic rays contain many different components. Since the intensity of the primary cosmic rays decreases exponentially as a result of the interactions of the constituents of the atmosphere, most of the components arriving at ground level consist of the secondary cosmic rays. The secondary cosmic rays at the ground are the hard
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component, most of which are muons. Variations of the cosmic rays flux are caused not only by solar activity but also by the changes in the geomagnetic field and meteorological processes. The intensity of muon flux at the ground level varies under the impact of atmospheric conditions. Thus, muon flux variations carry information about atmospheric processes and the investigation of them demands the development of new experimental approaches. That is why hard cosmic ray flux can be an indirect indication of a change in atmospheric pressure. 2. The methodology of the hard cosmic ray and atmospheric pressure research Cosmic radiation consists of soft and hard component. The main aim of the experimental research is to investigate hard cosmic component flux and its variations near the surface of the ground. The hard cosmic component at ground level mainly consists of muons. All experimental tests were carried out with gamma spectrometer having a scintillation NaI(Tl) sensor. The gamma spectrometer used for measuring hard cosmic ray flux operates on a principle of a scintillation-photoelectric dosimeter. The main elements of a gamma spectrometer are a sensor and a photoelectric multiplier. They structure a sensitive element, which is placed in a lead protective chamber with 10–12 cm thick walls to absorb the soft component of cosmic radiation. The device records an amount of gamma quanta and muons after Compton scattering in the sensitive element. Hard cosmic ray flux measurements were carried out continuously every 15 min. The work analyses the data of HCRF observations for the period 2002–2008 in interval of energies 1.2–1.6 MeV. The data of atmospheric pressure was obtained from The Hydrometeorological Service of Lithuania. Atmospheric pressure amounts of data processing a database has been made. The prognosis of atmospheric pressure decrease by HCRF decrease is possible only from 8 to 13 h. in individual time intervals. Therefore in the present research the time interval was divided into four intervals: 8–9, 9–10, 11–12 and 12–13 h. The criteria of HCRF decrease between two consecutive days were proposed: –15 imp./h, –20 imp./h. The minimum decrease in atmospheric pressure of 4 hPa and more and also without criterion was chosen as an effect. However, the above mentioned time intervals do not forecast HCRF connection between its increase and the increase of atmospheric pressure in the interval of energies 1.2–1.6 MeV. Such connection was found in time intervals from 14 to 19 hours. This interval was divided into hourly intervals 14–15,
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15–16, 16–17, 17–18, 18–19 h. The criteria of proposed HCRF values in all time intervals must exceed 40 or 50 imp./h. 3. The results and their analysis of hard cosmic ray flux and atmospheric pressure research The review of literature shows that geomagnetic field fluctuation and the atmospheric processes leads to the instability of secondary cosmic ray flux at ground level. Thus, it is important to use statistical analysis of hard cosmic ray flux and atmospheric pressure values. The research used the data of hard cosmic ray flux (HCRF) for the period 2002–2008. The descriptive statistical analysis was carried out using SPSS v.17.0 mathematical program. The main statistical parameters of hard cosmic ray flux and atmospheric pressure values were calculated for the period 2002–2008. It is important to know how widely spread the values and what is their deviation from the mean. For this purpose, the average standard deviation was calculated. The skewness and kurtosis of HCRF and atmospheric pressure values are distributed normally. It means that the measured HCRF and atmospheric pressure values are spread around the average value, as a Gauss curve. Hard cosmic ray flux and atmospheric pressure values in individual seasons were statistically analyzed too. The analysis of the data shows that hard cosmic ray flux and atmospheric pressure values in different seasons of the year are similar to normal distribution. Descriptive statistics does not allow to carry out a more detailed analysis of the experimental data. Therefore, correlation and regression methods were applied. Correlation and regression analysis were carried out using Maple v.11.0 mathematical program. Correlation method of analysis reveals links between the values of the cause. It is only a quantitative measure of the connection strength. The HCRF and atmospheric pressure course for the period 2002–2008 was studied by Pearson’s correlation coefficientr with confidence interval (Table 1). These parameters are presented by formulas: n n n nxiyi xiyi ri12i1i1, n sxsy
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(1)
1212 rrtpnr,rtpnr, (2) wherex – hard cosmic ray flux (HCRF);y – atmospheric pressure values; x,y – standard deviations;xi,yi observations of variable thex,y; x,y average values of variable thex,y; n – data of observations; F– standard distribution function of normal distribution;p– probability value, tpF112p. Table 1.Correlation coefficients between HCRF and atmospheric pressure and their confidence intervals in 1.2–1.6 MeV interval of energies Year Pirson correlation Confidence intervals of Pirson coefficient correlation coefficient (p0.95) 2002 –0.470.55…–0.39 2003 –0.43 –0.51…–0.34 2004 –0.46 –0.54...–0.36 2005 –0.53 0.61…–0.45 – 2006 –0.560.63…–0.48 2007 –0.57 –0.63…–0.49 2008 –0.57 –0.65…–0.49 Analysis of the data of Table 1 shows an obvious relation between HCRF and atmospheric pressure values. They are negative, but high enough and statistically significant. It means that HCRF and atmospheric pressure course have an inverse relationship. Inverse correlation between HCRF and atmospheric pressure monthly values can be represented graphically. An example of inverse correlation is shown in Fig. 1. In the next stage of the research regression analysis was applied. Regression analysis is a statistical tool for the investigation of the relationship between variables. A simple linear regression model attempts to explain the relationship between two or more variables using a straight line. 10
HCRF Atmosferic pressure
185 1040 180 1030 1020 175 1010 170 1000 165990 160 980 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 Days Fig. 1.Inverse correlation between HCRF and atmospheric pressure values in March 2007 A simple linear regression between hard cosmic ray flux and atmospheric pressure values was calculated for the time period 2002–2008 and each season of the year. Linear regression analysis results showed that for each individual season the line inclination angles were different. Maximum line inclination angle refers to winter and summer seasons. Minimum line inclination angle refers to spring and autumn seasons. It means that the connection between hard cosmic ray flux and atmospheric pressure values depends on the season in general. In the next stage of the research hard cosmic ray flux was researched in certain energy spectrum sections. It was determined that changes in atmospheric pressure were related to the changes in the value of HCRF only in hourly intervals. It was noticed that energy spectrum sections of HCRF are constantly changing. There are hourly, daily and monthly changes of HCRF values. An example of HCRF values in monthly average values for the time period 2002–2008 in interval of energies 1.2–1.6 MeV is given in Fig. 2. It was noticed that in different months the absolute values of HCRF varied. The maximum of HCRF values was registered in winter–autumn season, the minimum in summer–spring season. It is well known that the weather in middle latitudes strongly depends on the baric systems (cyclones and anticyclones) arising and developing over oceans. Therefore, studies of the influence of cosmic rays and related phenomena on cyclonic and anticyclonic activities are of great importance in forecasting the weather anomalies.
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