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Seminars at MPS

ESPOS

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ESP Online Seminar: The association of RHESSI flares to the Hale Sector Boundary and Active Longitudes (K. Loumou)

Are some parts of the Interplanetary Magnetic Field’s (IMF) neutral line more flare energetic than others? What are Hale Sector Boundaries (HSBs) and are they connected with flares? Do they have anything to do with Active Longitudes? In this work, I will discuss how RHESSI flares are associated with structures in the solar magnetic field termed as HSBs. If you think of the large-scale domains of different polarity that the IMF is formed of, they the parts of the boundary between them, that have the same polarity change as the sunspots back at the Sun. As the polarity of sunspots follows Hale’s law, the HSB of a particular polarity change will only occur in one hemisphere per cycle, and then alternate in the next cycle. It has previously been shown that HSBs coincide with stronger magnetic fields and more frequent flare occurrence (Dittmer 1975, Svalgaard & Wilcox 1976, Svalgaard et al. 2011). I will explain how we extended this work through solar cycles 23 and 24 using RHESSI flare locations from2002 to 2016. We compared these flares to the HSBs determined using two different methods. One uses the polarity change at the Earth to estimate when the HSB was at solar central meridian and the other uses Potential Field Source Surface (PFSS) extrapolations to identify the HSB for all times. We found that for both Cycle 23 and 24 more than 40% of non-limb flares were located near a HSB, a correlation that varies with cycle phase and hemisphere. I will describe how this evolves with time and the potential of these approaches for assisting flare forecasting. We then used the locations of HSBs calculated with the first method,using Earth-based data, to a Carrington rotation system and comparedthem with the migration paths of Active Longitudes as show in Gyenge et al. (2016). We found that there are times where they overlap, but that is not happening in a consistent manner. They often move at different rates relative to each other (and the Carrington solar rotation rate) and these vary over each Cycle. [more]

15525 1537865884

S3 Seminar: Coronal loop heating

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15526 1537865898

S3 Seminar: Numerical Simulations of Solar Convection using a Local Box Model

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15383 1537865912

S3 Seminar: The effect of inclination on solar brightness variations

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15384 1537865929

S3 Seminar: Inversions of straylight-corrected slit spectra

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15385 1537865943

S3 Seminar: The distribution of volatiles in the lunar interior

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15389 1537865959

S3 Seminar: Layerings in cometary nuclei

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15390 1537865974

S3 Seminar: Long-time solar and stellar 3-D convection simulations

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15386 1537865987

S3 Seminar: Exploring the depth dependence of solar equatorial Rossby waves

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16508 1542975173

MPS Seminar: Priorities for ground based solar physics: the DKIST and SPRING eras (V. Martínez Pillet)

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