HAO Research Highlights

Graphic depicting Angstrom images of the cavity
December 11, 2019

Gibson et al. have analyzed a long-lived cavity observed from 17 March 2012 to 21 March 2012. For this cavity we applied a differential emission measure method to obtain both a temperature distribution and a value of the average temperature during all five observational days.

Figure of LTR simulation results of the ionospheric states
October 31, 2019

Subauroral polarization stream (SAPS) are latitudinally narrow flow channels of large westward plasma drifts in the subauroral ionosphere.

Figure of 150-km echoes and WACCM-X simulated electron densities during the solar flare
October 31, 2019

A puzzling feature of the Earth’s equatorial upper atmosphere is the occurrence of enhanced VHF radar echoes near 150-km altitude. These so-called 150-km echoes have been observed for over 50-years, and occur nearly every day, making them a persistent feature of the equatorial ionosphere.

Graph depicting the second Waldmeier effect-WE2
October 8, 2019

One of the most robust features of the solar magnetic cycle is that the stronger cycles rise faster than the weaker ones. This is popularly known as the Waldmeier Effect, which is known for more than 100 years.

Graphic depicting Linear polarization azimuth
October 3, 2019

The magnetic field in the corona is important for understanding solar activity. Linear polarization measurements inforbidden lines in the visible/IR provide information about coronal magnetic direction and topology.