Research Highlights

Research Highlights

A selection of highlights culled from publications by HAO staff.

A series of 6 very colorful graphs showing daily tidal amplitudes

Planetary wave (PW) generation in the thermosphere driven by the PW-modulated tidal spectrum

J. M. Forbes, X. Zhang, and A. Maute, (2020) use the NCAR thermosphere-ionosphere-electrodynamics general circulation model (TIE-GCM) to conduct numerical experiments that isolate and elucidate a substantial modification of the quasi-6-day wave (Q6DW) above 110 km due to presence of the planetary wave (PW) modulated tidal spectrum.

Flow chart showing requirements from 3 science questions

Solar Transition Region UltraViolet Explorer (STRUVE) requirements flow down to design

In this paper, Johnathan Gamaunt, Angelica Berner, Alfred de Wijn, Paul Scowen, and Robert Woodruff, aim to illustrate the flow down of requirements from the mission science objectives to design requirements while also giving an overview of the design developed from the concept study. This mission, funded by NASA, uses the Solar Transition Region UltraViolet Explorer (STRUVE) miniature satellite conceived to study the magnetic field in the solar atmosphere.

A graph showing colored dots representing: True Negative; False Positive; True Positive, False Negative

Predicting the Geoeffectiveness of CMEs Using Machine Learning

Andreea-Clara Pricopi, Alin Razvan Paraschiv, Diana Besliu-Ionescu, and Anca-Nicoleta Marginean state, in the Astrophysical Journal, that coronal mass ejections are the most important space weather phenomena, being associated with large geomagnetic storms, and having the potential to cause disturbances to telecommunications, satellite network disruptions, and power grid damage and failures.

Very colorful graphics

Origin of Dawnside Subauroral Polarization Streams during Major Geomagnetic Storms

Dong Lin, Wenbin Wang, Viacheslav Merkin, and Chaosong Huang show that solar eruptions of mass and magnetic field can trigger geospace storms. The most well-known storm phenomenon is the aurorae in the Earth's high latitude upper atmosphere. They emphasize how extremely high storm activity levels may have severe adverse effects on human society and infrastructure.

Fe XIII 1074.68 nm emission over atmospheric absorption (normalized) in the He I Cryo-NIRSP wavelength range with all labeled candidate lines.

A Spectroscopic Survey of Infrared 1–4 μm Spectra in Regions of Prominent Solar Coronal Emission Lines of Fe XIII, Si X, and Si IX

Authors Aatiya Ali, Alin Razvan Paraschiv, Kevin Reardon, and Philip Judge, assert that the infrared solar spectrum contains a wealth of physical data about the Sun and is being explored using modern detectors and technology with new ground-based solar telescopes. One such instrument will be the ground-based Cryogenic Near-IR Spectro-Polarimeter of the Daniel K. Inouye Solar Telescope.

CLEDB 2-line magnetic inversion algorithm flowchart. An important aspect is the delivery of multiple possible solutions for each observation at the last step. Note that the x-coordinate of the point in space, as well as nearest electron density, are returned along with B. The figure uses the notation Vobs and Vdb for observed and computed values of the amplitudes of the Stokes parameters corresponding to O3 and S3 (B = 1) in the text.

Efficient and Automated Inversions of Magnetically-Sensitive Forbidden Coronal Lines: CLEDB - The Coronal Line Emission DataBase Magnetic Field Inversion Algorithm

Alin Paraschiv and Philip Judge present CLEDB, a single point inversion algorithm for determining magnetic parameters using spectro-polarimetric measurements of emission lines formed in the solar corona.

The solar spectrum seen at low resolution, below the atmospheric cutoff at 3100 Angstrom

Optimal spectral lines for measuring chromospheric magnetic fields

This paper identifies spectral lines from EUV to infrared wavelengths which are optimally suited to measuring vector magnetic fields as high as possible in the solar atmosphere.

3D view of the simulated corona; bottom panel: magnetogram; back panel: synthetic AIA 211A coronal image; middle vertical plane: volumetric emissivity. Field lines are included for reference.

The Coronal Veil

Coronal loops, seen in solar coronal images, are believed to represent emission from magnetic flux tubes with compact cross sections. Anna Malanushenko, Matthias Rempel and others, examine the 3D structure of plasma above an active region in a radiative magnetohydrodynamic simulation to locate volume counterparts for coronal loops.

3 Scatter density plots of the retrieved value of Blos

Effects of spectral resolution on simple magnetic field diagnostics of the Mg II h & k lines

Rebecca Centeno, Matthias Rempel, Roberto Casini, and Tanausu del Pino Aleman study the effects of finite spectral resolution on the magnetic field values retrieved through the weak field approximation (WFA) from the cores of the Mg II h&k lines.