Η πιθανή επίδραση της μεταβλητότητας της ροής της κοσμικής ακτινοβολίας στη νέφωση, στην ατμοσφαιρική κατακρήμνιση και συνεπώς στο πλανητικό ισοζύγιο ακτινοβολίας έχει εγείρει μια έντονη έρευνα τα τελευταία χρόνια. Επιχειρείται μια κριτική ανασκόπηση των εργασιών στις οποίες έχει μελετηθεί η σχέση μεταξύ γαλαξιακών κοσμικών ακτίνων και ατμοσφαιρικών διεργασιών και το ενδιαφέρον επικεντρώνεται σε αυτές που αφορούν στην επίδραση των βραχυχρόνιων μεταβολών της γαλαξιακής κοσμικής ροής στα νέφη και την ατμοσφαιρική κατακρήμνιση. Η συσχέτιση μεταξύ των επεισοδίων βροχόπτωσης και της κοσμικής ακτινοβολίας είναι πολύ μικρή για να αποδείξει άμεση επίδραση των κοσμικών ακτίνων στην ατμόσφαιρα. Συνεπώς, σκοπός αυτής της μελέτης είναι να ερευνήσει τη συσχέτιση μεταξύ των επεισοδίων βροχόπτωσης και των μειώσεων της γαλαξιακής κοσμικής ακτινοβολίας σε ημερήσια βάση. Η μεθοδολογία που υιοθετείται παρέχει έναν χρήσιμο τρόπο διαχωρισμού του σήματος της γαλαξιακής κοσμικής ακτινοβολίας από άλλες πιθανές εξωτερικές και εσωτερικές επιδράσεις στην ατμοσφαιρική κατακρήμνιση. Η βασικότερη μέριμνα αυτής της μελέτης είναι ο προσδιορισμός ενός προτύπου επιβεβαίωσης του ορίου μείωσης και της χρονικής περιόδου της κοσμικής ακτινοβολίας που θεωρείται ως μείωση Forbush, αφού και στη βιβλιογραφία η μείωση Forbush ορίζεται μάλλον αυθαίρετα. Η μείωση του ρυθμού ατμοσφαιρικής κατακρήμνισης κατά τη διάρκεια των μειώσεων Forbush είναι σύμφωνη με τα αποτελέσματα της ερευνητικής εργασίας και άλλων επιστημόνων. Τέλος, εκτιμάται ένας πιθανός μηχανισμός μικροφυσικής των νεφών που ερμηνεύει τη συμπεριφορά των μειώσεων Forbush για τα πολύ έντονα επεισόδια βροχόπτωσης. Η πειραματική μελέτη των θεμελιωδών μικροφυσικών αλληλεπιδράσεων μεταξύ της κοσμικής ακτινοβολίας και των νεφών και η ανάπτυξη νέας τεχνολογίας οργάνων θα βοηθήσει στην κατανόηση του φυσικού μηχανισμού κοσμικές ακτίνες - νέφη - κλίμα. / The possible influence of variability of the cosmic ray flux on cloud cover, on precipitation and thus on the radiation budget of the planet, has stimulated a lively investigation during the recent years. We attempt a critical review cites of those papers studying the relation between galactic cosmic rays and atmospheric processes and we focus on those which pertain the influence of short - term changes of galactic cosmic flux on clouds and precipitation. The correlation between precipitation events and cosmic rays is very low to prove the direct influence of cosmic rays in the atmosphere. Consequently, the scope of this study is to investigate the correlation between precipitation events and galactic cosmic ray decreases on a diurnal basis. The methodology adopted provides a useful way to dissociate the signal of galactic cosmic rays from other possible external and internal influences on precipitation. The basic concern of this study is the determination of a model to confirm the limit of cosmic ray decrease and the corresponding time of occurrence assumed as a Forbush decrease, since this decrease is arbitrarily defined in literature. The determined decrease of precipitation rate during the Forbush decreases is in accordance to the results of other scientists. Finally, we estimate a possible cloud microphysical mechanism which may interpret the impact of Forbush decreases for the heavy precipitation events. The experimental study of the fundamental microphysical interactions between cosmic rays and clouds and the development of new instrumentation will help to understand the physical mechanism cosmic rays – clouds – climate.

Orientador: Anderson Campos Fauth / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-28T23:49:34Z (GMT). No. of bitstreams: 1 Vasconcelos_DeboraNunesBarrosde_M.pdf: 12164737 bytes, checksum: b673ae31e92a75895beeb827173604e6 (MD5) Previous issue date: 2015 / Resumo: Desde os lançamentos dos satélites científicos, o estudo do Sol e a influência dos seus eventos nà Terra tem sido aprofundado constantemente devido as possíveis consequências no clima da Terra e a danos nos sistemas de comunicações. Entretanto, os detectores embarcados nos satélites tem limitações que não permitem medições de energias das partículas energéticas solares superiores a algumas centenas de MeV. Neste trabalho é descrita a construção, instalação e montagem do telescópio de múons, em Campinas-SP, denominado Muonca, para detecção dessas partículas da radiação cósmica secundária, originadas na atmosfera principalmente por interações de prótons. O principal objetivo deste experimento é a detecção de eventos solares transientes numa faixa de energia superior àquela operada pelos satélites. O fato do telescópio estár dentro, e próximo da região central, da Anomalia Magnética do Atlântico Sul, permite uma melhor detecção de partículas carregadas provenientes do espaço externo, pois o fluxo de partículas nessa região é maior. Foram construídos quatro detectores de partículas utilizando placas de cintilador plástico e tubos fotomultiplicadores que em conjunto formam os telescópios de múons do Muonca. Esses telescópios detectam múons verticais e inclinados a 45 graus vindos da direção Leste e da direção Oeste. Após a montagem do telescópio, a sua caracterização de eficiência de contagem foi realizada o seu valor é de (96,8 ± 0,4)%. O coeficiente barométrico foi medido, sendo seu valor igual a ? =(0,22 ± 0,04)%/mbar, condizente com outros experimentos de múons. Dados de 01 de abril de 2014 até 31 de janeiro de 2015 foram analisados e o mês de setembro de 2014 foi estudado detalhadamente. Neste mês foram um evento de decréscimo de Forbush da ordem de 1%. Os resultados do Muonca foram comparados com os resultados do monitor de nêutrons McMurdo o qual detectou o mesmo evento. Uma análise utilizando os resultados do satélite GOES15 da NASA mostrou que este Forbush foi originada por três CMEs, sendo que duas dessas ejeções foram associadas a flares de classe M4.6 e X1.6. O experimento Muonca foi construído com sucesso e está operando continuamente, permitindo o estudo da física solar através da detecção de múons no solo terrestre / Abstract: Since the launch of scientific satellites to study the Sun and the influence of their events on Earth has been constantly deepened because of the possible consequences in Earth's climate and the damage to the communications systems. However embedded in the satellite detectors have limitations relating to measurements of energies of the solar energetic particles larger than a few hundred MeV. This work describes the construction, installation and assembling of the muon telescope in Campinas-SP, called Muonca, to detect these particles of secondary cosmic radiation, originated in the atmosphere mainly by proton interactions. The main objective of this experiment is the detection of solar transient events in a higher energy that operated by satellites. The fact that the telescope be within, and near the central region of the South Atlantic Magnetic Anomaly, allows better detection of charged particles coming from outer space because the flux of particles in this region is higher. Four particle detectors, using plastic scintillator and photomultiplier tubes, which together form the muon telescopes Muonca were constructed. These telescopes detect vertical and inclined at 45 degrees muons coming from the East and West direction. After mounting the telescope, its counting efficiency was measured and its value is (96,8 ± 0,4)%. The barometric coefficient was measured, and its value of ? =(0,22 ± 0,04)%/mbar was obtained, beeing consistent with other muon experiments. Data from April 1st 2014 to January 31th 2015 were analyzed and September 2014 has been studied in detail. In this month the Muonca detected a Forbush decrease of the order of 1%. The results of Muonca were compared with the results of McMurdo neutron monitor which detected the same event. An analysis using the results of GOES15 NASA satellite showed that this Forbush originated three CMEs, and two of those ejections were associated with flares of M4.6 and x1.6 class. The Muonca experiment was successfull constructed and is operating continuously, allowing the study of solar physics through the muon detection in terrestrial soil / Mestrado / Física / Mestra em Física / 2012/1139485 / 2011/50193-4 / CAPES / FAPESP