Research Highlights

Research Highlights

A selection of highlights culled from publications by HAO staff.

WACCM-X simulation, vertical ExB drift

Tidal control of equatorial vertical ExB drift under solar minimum conditions

Han-Li Liu and Astrid Maute use a whole atmosphere general circulation model, WACCM-X, to reproduce the pattern of the vertical ion motion similar to that observed during low activity solar cycle periods. 

Measurement of gravity wave activity

Assessment of gravity waves from tropopause to thermosphere and ionosphere in high-resolution WACCM-X simulations

H.-L. Liu, P. H. Lauritzen, F. Vitt, and S. Goldhaber have developed a high-resolution whole atmosphere model (WACCM-X), which extends from the Earth surface to the upper thermosphere, that can partially resolve the small scale wave quantification. 

Instead heating arises within primarily unipolar fields above the chromosphere.

Magnetic fields beneath active region coronal loops

Philip Judge, Lucia Kleint, and Christoph Kuckein use measurements of photospheric and chromospheric magnetic fields from the GREGOR GRIS instrument, to refute the idea that magnetic reconnection of network magnetic fields with granular fields drives coronal heating.

NVST and CHASE observations, Feb 14

Comprehensive analysis of a filament-embedding solar active region at different stages of evolution

Sarah Gibson, et al. present a comprehensive study for a filament-embedding active region as determined from observations from multiple facilities including the Chinese Hα Solar Explorer (CHASE). The spectral resolution of CHASE is as high as 0.024 ̊A pixel−1, which enables an accurate determination of the chromospheric Doppler velocity that is especially crucial for probing the relative stable structure investigated here. 

Scenario of the faculae distribution

Exploring Spatial and Temporal Patterns in the Debrecen Solar Faculae Database

Anett Elek, Marianna B. Korsós, Mausumi Dikpati, Norbert G. Gyenge, Bernadett Belucz, and Robertus Erdélyi, using data from the Debrecen Solar Faculae Database, investigated the spatiotemporal distribution of photospheric faculae between 2010 May 1 and 2014 December 31. Photospheric faculae are markers of the solar magnetic field, appearing as bright regions along the edges of granules on the Sun's surface.

GOLD Namx left and right panels

Investigation of the physical mechanism of the formation and evolution of equatorial plasma bubbles during a moderate storm on September 17, 2021

Kun Wu, Liying Qian, Wenbin Wang, Xuguang Cai, Joseph M. Mclnerney investigate in detail the occurrence and evolution of ionospheric equatorial plasma bubbles (EPBs) during a moderate storm on September 17th, 2021, using Global-scale Observation of the Limb and Disk (GOLD) observations and Whole Atmosphere Community Climate Model-eXtended (WACCM-X) simulations.

Erupting magnetic flux rope

Comprehensive Radiative MHD Simulations of Eruptive Flares above Collisional Polarity Inversion Lines

Matthias Rempel, Georgios Chintzoglou, Mark C. M. Cheung, Yuhong Fan, and Lucia Kleint present a new simulation setup using the MURaM radiative Magnetohydrodynamic (MHD) code that allows to study the formation of collisional polarity inversion lines (cPILs) in the photosphere and the coronal response including flares. In this scheme we start with a bipolar sunspot configuration and set the spots on collision course by imposing the appropriate velocity field at the footpoints in the subphotospheric boundary.

Cycling magnetic behavior

Inflows towards Bipolar Magnetic Active Regions and Their Nonlinear Impact on a Three-Dimensional Babcock-Leighton Solar Dynamo Model

Kinfe Teweldebirhan, Mark Miesch, and Sarah Gibson investigate the role and impact of converging flows toward Bipolar Magnetic Regions (BMR inflows) on the Sun’s global solar dynamo. These flows are large-scale physical phenomena that have been observed and so should be included in any comprehensive solar dynamo model.

R-T growth rate and vertical ion drift

New Expression of the Field-line Integrated Rayleigh-Taylor Instability Growth Rate

Chun-Yen Huang, Tzu-Wei Fang, Arthur Richmond, Timothy Fuller-Rowell, Jenn-Yenq Liu research expressions of newly established Rayleigh-Taylor (R-T) instability growth rates, then perform calculations using the thermospheric and ionospheric conditions based on the coupled Whole Atmosphere Model and Ionosphere Plasmasphere Electrodynamic model (WAM-IPE). The parameters used in this calculation include the field-line integrated conductivities and currents, which consider the Quasi-Dipole Coordinates and the modifications to the equations of electrodynamics.