Presentation Title

Oscillations in Emerging Active Regions of the Sun (OEARS)

Faculty Mentor

[3] Karin Muglach

Start Date

18-11-2017 2:15 AM

End Date

18-11-2017 3:15 AM

Location

Ursa Minor 150

Session

Poster 3

Type of Presentation

Poster

Subject Area

physical_mathematical_sciences

Abstract

Oscillations in Emerging Active Regions on the Sun

Mathew Garcia1, Andrea Minot2, Karin Muglach3

1College of the Desert, 43-500 Monterey Ave, Palm Desert, CA 92260, United States

2Dickinson College, 28 N College St, Carlisle, PA 17013, United States

3Heliophysics, NASA Goddard Space Flight Center, Mail Code 674, Greenbelt, MD, 20771, United States

Active regions (AR) on the Sun are directly related to space weather phenomena like flares and coronal mass ejections (CMEs). It is well known that both can have impacts not only on Earth, but also on in nearby orbits and beyond. Predicting when and where active regions will emerge at the surface of the Sun would strengthen space weather forecasting abilities.

In this study, data from the Solar Dynamics Observatory (SDO) are used to produce images of the magnetic field and Doppler Velocity at the photosphere of the Sun. This data is used to study the emergence of ARs at the surface of the Sun. Since global oscillations that travel through the solar interior are modified by the magnetic field, the oscillation patterns in and around ARs should be different from the oscillation patterns in the quiet, non-active Sun. Thus, a change in oscillation patterns can be determined before an AR is visible at the Sun’s surface. Using Fast Fourier Transforms, the oscillation patterns can be calculated from the SDO Dopplergrams. Magnetograms provide the time when the magnetic field of the active region reaches the solar surface. Thus, both the calculated oscillation frequencies and power can be compared to the information of an AR’s emergence in the magnetograms. In particular, it can be determined if there is any time delay between the change of oscillation power and magnetic field emergence.

For this particular AR studied, it was found that the 5-min oscillation power starts to decrease at the time the AR emerges. The 3-min oscillation power also decreases first but increases again a few hours after the start of the emergence. This observation is probably due to 3-min oscillation power halos around the AR. This has been observed before. A few hours before the AR starts to emerge, an increase was found in both 5-min and 3-min oscillation power. This result is promising, however, this has not been observed before and must be verified with additional observations.

Summary of research results to be presented

Both oscillation power show an increase of power a few hours prior to the emergence time. This effect is promising but unexplained, this must be confirmed by additional observations. We are planning to analyze several other ARs to confirm these results and to investigate their possible use for the forecasting of AR emergence.

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Nov 18th, 2:15 AM Nov 18th, 3:15 AM

Oscillations in Emerging Active Regions of the Sun (OEARS)

Ursa Minor 150

Oscillations in Emerging Active Regions on the Sun

Mathew Garcia1, Andrea Minot2, Karin Muglach3

1College of the Desert, 43-500 Monterey Ave, Palm Desert, CA 92260, United States

2Dickinson College, 28 N College St, Carlisle, PA 17013, United States

3Heliophysics, NASA Goddard Space Flight Center, Mail Code 674, Greenbelt, MD, 20771, United States

Active regions (AR) on the Sun are directly related to space weather phenomena like flares and coronal mass ejections (CMEs). It is well known that both can have impacts not only on Earth, but also on in nearby orbits and beyond. Predicting when and where active regions will emerge at the surface of the Sun would strengthen space weather forecasting abilities.

In this study, data from the Solar Dynamics Observatory (SDO) are used to produce images of the magnetic field and Doppler Velocity at the photosphere of the Sun. This data is used to study the emergence of ARs at the surface of the Sun. Since global oscillations that travel through the solar interior are modified by the magnetic field, the oscillation patterns in and around ARs should be different from the oscillation patterns in the quiet, non-active Sun. Thus, a change in oscillation patterns can be determined before an AR is visible at the Sun’s surface. Using Fast Fourier Transforms, the oscillation patterns can be calculated from the SDO Dopplergrams. Magnetograms provide the time when the magnetic field of the active region reaches the solar surface. Thus, both the calculated oscillation frequencies and power can be compared to the information of an AR’s emergence in the magnetograms. In particular, it can be determined if there is any time delay between the change of oscillation power and magnetic field emergence.

For this particular AR studied, it was found that the 5-min oscillation power starts to decrease at the time the AR emerges. The 3-min oscillation power also decreases first but increases again a few hours after the start of the emergence. This observation is probably due to 3-min oscillation power halos around the AR. This has been observed before. A few hours before the AR starts to emerge, an increase was found in both 5-min and 3-min oscillation power. This result is promising, however, this has not been observed before and must be verified with additional observations.