Research Highlights

Research Highlights

A selection of highlights culled from publications by HAO staff.

Hanle diagrams

A unifying polarization formalism for electric- and magnetic-multipole interactions

R. Casini, R. Manso Sainz, A. Lopez Ariste, and N. Kaikati extend the spherical tensorial formalism for polarization to the treatment of eletric- and magnetic-multipole transitions of any order, to model the radiation anisotropy affecting the scattering of radiation in an electric-quadrupole transition, and the associated Hanle effect in the presence of a magnetic field.

Longitude-latitude distribution map

A Community Ionosphere-Thermosphere Observing System Simulation Experiment (OSSE) Tool

Chih-Ting Hsu, et al. in this study demonstrate the utility of DART/TIEGCM as an IT OSSE tool, using synthetic observations simulated using a currently planned NASA Geospace Dynamics Constellation (GDC) observing system design. Five sets of OSSEs are carried out to compare the effects of assimilating various combinations of prospective GDC observations (e.g., neutral temperature, neutral wind, neutral composition, atomic oxygen ion density, and ion and electron temperature) during a major geomagnetic storm period of the St Patrick's Day Storm on March 17, 2013. 

pre-reversal enhancement during geomagnetic quiet time period

MAGE Model Simulation of the Pre-reversal Enhancement and Comparison with ICON and Jicamarca ISR Observations

Qian Wu, Wenbin Wang, Dong Lin, Liying Qian, Chaosong Huang, and Yongliang Zhang use the latest coupled geospace model MAGE (Multiscale Atmosphere-Geospace Environment) and observations from Jicamarca ISR and ICON IVM instrument, we examine the pre-reversal enhancement during geomagnetic quiet time period.

Thermospheric wind observations from HIWIND

HIWIND Balloon and Antarctica Jang Bogo FPI High Latitude Conjugate Thermospheric Wind Observations and Simulations

Qian Wu, Dong Lin, Wenbing Wang, Liying Qian, Geonhwa Jee, Changsup Lee, and Jeong-han Kim use balloon instrument in the northern hemisphere and ground based instrument in the southern hemisphere to study the conjugacy of the thermospheric winds of high latitudes.

Intraseasonal variability regression patterns

Tropical and Subtropical South American Intraseasonal Variability: A Normal-Mode Approach

André SW Teruya, Víctor C Mayta, Breno Raphaldini, Pedro L Silva Dias, and Camila R Sapucci use a normal-mode decomposition method to analyze South American intraseasonal variability (ISV). This demonstrated that a realistic circulation can be reproduced, giving a powerful tool for diagnosing and studying the dynamics of waves and the interactions between them in terms of their ability to provide causal accounts of the features seen in observations.

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. 

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. 

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.

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.