Research Highlights
Research Highlights
A selection of highlights culled from publications by HAO staff.
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A Study on the Nested Rings CME Structure Observed by the WISPR Imager Onboard Parker Solar Probe
Published: December 2024. Sarah Gibson, et al. present an analysis of a CME and its interior structure observed during the seventh solar encounter of the Parker Solar Probe, utilizing the data from its Wide-Field Imager for Solar PRobe (WISPR) heliospheric imager. They observe a complex CME structure consisting of non-concentric nested rings, which we argue is a signature of the embedded helical magnetic flux rope (MFR) of the CME.
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Evolution Of Amplitude And Longitude Phase Of Tachocline Rossby Waves Diffusing To The Photosphere
Published: 05 November 2024. Mausumi Dikpati, Peter A Gilman, Breno Raphaldini, Scott W McIntosh improve on the 2020 MHD Rossby wave model to include a hydrodynamic turbulent convection zone (CZ). This new approach enabled them to examine how MHD Rossby waves generated in the tachocline might diffuse upward through the CZ to the solar surface.
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SynCOM: An Empirical Model for High-Resolution Simulations of Transient Solar Wind Flows
Published: November 2024. Sarah Gibson, V. P. Moraes Filho, V. Uritsky, B. J. Thompson, and C. E. DeForest demonstrate how SynCOM can be employed to assess the precision and performance of two different flow tracking methods. By providing a ground-truth based on observational data, we highlight the importance of SynCOM in confirming observational standards for detecting coronal flows.
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The Formation Mechanism of Merged EIA During a Storm on 4 November 2021
Kun Wu, Liying Qian, Wenbin Wang, Xuguang Cai, and Joseph Mclnerney conduct an in-depth analysis of Whole Atmosphere Community Climate Model-eXtended (WACCM-X) simulations to examine physical mechanisms of the formation and evolution of an equatorial ionization anomaly (EIA) merging phenomenon during a storm on November 4th, 2021.
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Image instabilities and polarization cross-talk
In this publication, Roberto Casini and Alfred de Wijn expand on their previous study of the impact of atmospheric seeing on polarization cross-talk, and show how the formalism that was developed in that work can be applied to treat the case of spatial modulators of polarization.
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Transport of Nitric Oxide in the Winter Mesosphere and Lower Thermosphere
Han-Li Liu observes that nitric oxide (NO) is one of the most important cooling agent in the thermosphere and an important species for the energy balance of the upper atmosphere and the chemistry and dynamics of the middle atmosphere.
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Impact of Upward Propagating Migrating Diurnal and Semidiurnal Tides on the Ionosphere-Thermosphere Seasonal Variation
N. M. Pedatella, K. Wu, L. Qian, and Q. Gan use WACCM-X to investigate the impact of the upward propagating migrating diurnal (DW1) and semidiurnal (SW2) tides on the seasonal variability in the ionosphere and thermosphere. The results demonstrate that the upward propagating DW1 and SW2 both have significant effects on the ionosphere and thermosphere, including influencing the seasonal variability.
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Magnetohydrodynamic Instabilities of Double Magnetic Bands in a Shallow-water Tachocline Model: II Teleconnection Between High- and Low-latitude Bands and Across Equator
Mausumi Dikpati, Bernadett Belucz, Robertus Erdelyi, Peter A Gilman, Scott W McIntosh and Breno Raphaldini find that latitude-location, latitude-separation, and amplitude of the toroidal magnetic field bands strongly influence the latitudinal structure and growth rates of the unstable modes, of both symmetries about the equator. These properties can lead to 'teleconnections' between low- and high-latitudes in each hemisphere and across the equator.
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Magnetic Field Evolution of the Solar Active Region 13664
Robert Jarolim, Astrid M. Veronig, Stefan Purkhart, Peijin Zhang, and Matthias Rempel provide a detailed record of the magnetic field evolution of AR 13664, now publicly available for further research. Their results show that drops in free magnetic energy coincide with large solar flares, and that all modeled X-class flares were associated with a sudden decrease in magnetic energy.