Research Highlights

Research Highlights

A selection of highlights culled from publications by HAO staff.

Coronal hole centroid latitude vs. Carrington Rotation

Study of Coronal Hole Lifetimes

Ian Hewins, Sarah Gibson, David Webb, Bob McFadden, Thomas Kuchar, and Barbara Emery-Geiger use the McIntosh Archive of solar features to analyze the evolution of coronal holes over more than three solar cycles. They demonstrate that coronal hole positions and lifetimes change dramatically on time scales from months to yrs, and that the pattern of these changes is clearly linked to the solar activity cycle.

Locations of Solar Parker Probe described as data points

Critical Science Plan for the Daniel K. Inouye Solar Telescope (DKIST)

Sarah Gibson, Philip Judge, Mark Rast, Nazaret Bello Gonzalez, Luis Bellot Rubio, and others assert that the Daniel K. Inouye Solar Telescope (DKIST) will revolutionize our ability to measure, understand and model the basic physical processes that control the structure and dynamics of the Sun and its 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.

Two stacked graphs comparing proton flux against solar flux

Gleissberg Cycle Dependence of Inner Zone Proton Flux

Authors E. J. Bregou, M. K. Hudson, B. T. Kress, M. Qin, and R. S. Selesnick find a long-term increase in measured proton flux over four ~11 year cycles of solar activity. The inner zone proton radiation belt consisting of 10’s to >100 MeV protons trapped in the Earth’s magnetic field is examined from 1980 to mid-2021 using measurements from four NOAA POES satellites.

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.

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.

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.