Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.766518
Title: Leap forward in Space Weather forecast : novel prediction of flares
Author: Korsos, Marianna
ISNI:       0000 0004 7655 2995
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Access from Institution:
Abstract:
In this thesis, our aim was to further test and develop our WG_M flare prediction method. First, we extended the number and GOES flare intensity range of the previously applied data sample to reinforce the two diagnostic properties of the WG_M method. This extended statistical sample confirmed that the characteristic preflare behaviour of the WG_M and distance (Dpn) parameters both need to appear concurrently for a follow-up flaring to take place in a d-spot. Furthermore, we verified the relationship between the value of highest flare class intensity (from B- to X-class) of a flaring AR and the maximum value of WG_M. Also, the new sample reaffirmed the linear connection between the duration of the converging and diverging motions of the barycenters of opposite polarities up to flare onset. Next, we further probed the WG_M method, by applying it to magneto-hydrodynamic simulations modelling solar-like flares. The pre-flare evolution of WG_M and the behavior of Dpn at various heights identified in the simulated sample d-type AR were investigated as a case study. We identified the optimum heights where Dpn yielded the earliest sign of pre-flare behaviour, compared its to photospheric counterpart. These loci in height, found for being most beneficial for predicting flares, agree reasonably well with the heights of the occurrence of flares themselves. We also estimated the expected time of flare onsets from the durations of the convergingdiverging motion of the barycenters of opposite polarities before each flare. The estimated onset time and the actual time of occurrence of each flare were in good agreement at the corresponding optimum heights. Finally, based on the analyses of the simulated flaring AR cases, we proposed to extend our studies into 3D embracing a solar atmospheric region from the photosphere into low corona. To make advances, over a dozen of ARs were analysed. We showed that if the optimum height is between 1000-1800 km in the solar atmosphere then this would allow us to increase the flare prediction with 3.2 hrs ±2.5 hours lead time.
Supervisor: Ruderman, Michael Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.766518  DOI: Not available
Share: