prikaz prve stranice dokumenta Određivanje parametara modela geomagnetske aktivnosti primjenom nelinearne metode najmanjih kvadrata
  Download
PDF 7.74 MB
master's thesis
Određivanje parametara modela geomagnetske aktivnosti primjenom nelinearne metode najmanjih kvadrata
Zagreb: University of Zagreb, Faculty of Science, 2023. urn:nbn:hr:217:856685
Ćorković, Martina
University of Zagreb
Faculty of Science
Department of Geophysics

Institutional repository: Repository of the Faculty of Science

Cite this document

Ćorković, M. (2023). Određivanje parametara modela geomagnetske aktivnosti primjenom nelinearne metode najmanjih kvadrata (Master's thesis). Zagreb: University of Zagreb, Faculty of Science. Retrieved from https://urn.nsk.hr/urn:nbn:hr:217:856685

Ćorković, Martina. "Određivanje parametara modela geomagnetske aktivnosti primjenom nelinearne metode najmanjih kvadrata." Master's thesis, University of Zagreb, Faculty of Science, 2023. https://urn.nsk.hr/urn:nbn:hr:217:856685

Ćorković, Martina. "Određivanje parametara modela geomagnetske aktivnosti primjenom nelinearne metode najmanjih kvadrata." Master's thesis, University of Zagreb, Faculty of Science, 2023. https://urn.nsk.hr/urn:nbn:hr:217:856685

Ćorković, M. (2023). 'Određivanje parametara modela geomagnetske aktivnosti primjenom nelinearne metode najmanjih kvadrata', Master's thesis, University of Zagreb, Faculty of Science, accessed 25 December 2024, https://urn.nsk.hr/urn:nbn:hr:217:856685

Ćorković M. Određivanje parametara modela geomagnetske aktivnosti primjenom nelinearne metode najmanjih kvadrata [Master's thesis]. Zagreb: University of Zagreb, Faculty of Science; 2023 [cited 2024 December 25] Available at: https://urn.nsk.hr/urn:nbn:hr:217:856685

M. Ćorković, "Određivanje parametara modela geomagnetske aktivnosti primjenom nelinearne metode najmanjih kvadrata", Master's thesis, University of Zagreb, Faculty of Science, Zagreb, 2023. Available at: https://urn.nsk.hr/urn:nbn:hr:217:856685

Metadata
TitleOdređivanje parametara modela geomagnetske aktivnosti primjenom nelinearne metode najmanjih kvadrata
Title (english)Parameter estimation of a geomagnetic activity model using non-linear least squares method
AuthorMartina Ćorković
MentorGiuliana Verbanac (mentor)
Committee memberGiuliana Verbanac (predsjednik povjerenstva)
Committee memberAntun Marki (član povjerenstva)
Committee memberIvica Sović (član povjerenstva)
Committee memberMirko Orlić (član povjerenstva)
Committee memberJosip Stipčević (član povjerenstva)
GranterUniversity of Zagreb
Faculty of Science
(Department of Geophysics)
Zagreb
Defense date and country2023-10-27, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Geophysics
Other Geographic Disciplines
Abstract
U ovom radu ispitujemo uspješnost O’Brien-McPherronovog modela za prognozu geomagnetskih oluja na temelju poremećaja Dst indeksa za geomagnetske oluje uzrokovane koroninim izbačajima mase u razdoblju od 1996. do 2020. godine. Koronini izbačaji mase su najsnažniji izbačaji plazme sa Sunca koji mogu doći do Zemlje i uzrokovati promjene magnetskog polja unutar magnetosfere koje se mogu detektirati magnetogramima na površini Zemlje. Također, nelinearnom metodom najmanjih kvadrata tražimo nove vrijednosti parametara tog modela α, b i Vq s obzirom na četiri razine solarne aktivnosti definirane preko broja Sunčevih pjega. Isti postupak primjenjujemo i za O’Brien-McPherronov model koji uključuje Svalgaardovu popravku za utjecaj elektičnog polja međuplanetarnog magnetskog polja na magnetosferu s obzirom na nagib dipola. Rezultati su pokazali da O’Brien-McPherronov model ne može u potpunosti prognozirati magnitude maksimuma i minimuma Dst indeksa te da su odstupanja najveća za nisku i visoku razinu aktivnosti. Pokazali smo da je parametar α umjereno linearno koreliran s brojem Sunčevih pjega, a Vq slabo, dok b ne ovisi o razini aktivnosti. Konačno, pokazali smo da Svalgaardova popravka ne unosi značajno poboljšanje za analizu pojedinačnih geomagnetskih oluja.
Abstract (english)
In this study, we investigate the effectiveness of the O’Brien-McPherron model for forecasting geomagnetic storms based on disturbances in the Dst index for geomagnetic storms caused by coronal mass ejections from 1996 to 2020. Coronal mass ejections are the most powerful plasma ejections from the Sun that can reach Earth and cause changes in the magnetic field within the magnetosphere, which can be detected by magnetograms on the Earth’s surface. Additionally, we seek new values for the parameters of this model α, b and Vq based on four levels of solar activity, defined by the number of sunspots, using nonlinear least squares. We apply the same precedure to the O’Brien-McPherron model which includes Svalgaard’s correction. Svalgaard’s correction describes the influence of the interplanetary magnetic field’s electric field on the magnetosphere with respect to the dipole tilt. The results have shown that the O’Brien-McPherron model cannot fully predict the magnitudes of the maximum and the minimum of the Dst index. The deviations in predicted magnitudes are greatest for low and high activity levels. We have demonstrated that the parameter α is moderately linearly correlated with the number of sunspots, while Vq is only weakly correlated. Parameter b does not depend on the activity level. Finally, we have shown that Svalgaard’s correction does not significantly improve the analysis of individual geomagnetic storms.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:217:856685
Study programmeTitle: Graduate university study pf Physics - Geophysics; specializations in: Seismology and Physics of the Earth's Interior, Meteorology and Physical Oceanography
Course: Meteorology and Physical Oceanography
Study programme type: university
Study level: graduate
Academic / professional title: magistar/magistra fizike – geofizike (magistar/magistra fizike – geofizike)
Type of resourceText
File originBorn digital
Access conditionsOpen access
Embargo expiration date: 2024-10-27
Terms of useLicence In copyright icon
Created on2023-11-06 12:28:08