HAO Research Highlights

Graphic image of active-regions' toroid patterns
February 23, 2021

Dikpati, et. al., derive magnetic toroids from surface magnetograms by employing a novel optimization method based on Trust Region Reflective algorithm. Toroids obtained are combinations of Fourier modes (amplitudes and phases) with low longitudinal wavenumbers.

Graphic depicting root-mean-square difference of the plasma drift
February 4, 2021

A Case Study During a Minor Storm Period Under Solar Minimum Conditions: The dayside equatorial ionospheric electrodynamics exhibits strong variability driven simultaneously by highly changeable external forcings that originate from the Sun, magnetosphere, and lower atmosphere.

Graphic image depicting spectro-polarimetric data
February 2, 2021

In 2014 HAO built a polarimetric modulator for the CRISP instrument on the Swedish 1-m Solar Telescope in La Palma, using the principles of polychromatic modulation previously developed by HAO scientists. This paper discusses the processes by which the modulator was designed, built, and tested.

Graphic image of the magnetic Bx component
January 28, 2021

Accurate models of the spatial structure of ionospheric magnetic fields in the daily variation (DV) band (periods of approximately a few hours to a day) would enable use of magneto-variational methods for three-dimensional imaging of upper mantle and transition zone electrical conductivity.

Graphic depicting migrating semidiurnal tide
January 28, 2021

Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere-ionosphere eXtension (SD-WACCMX) simulations are used to investigate the solar migrating semidiurnal tide (SW2) around September equinox at middle to high latitudes in the Northern Hemisphere.

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