HAO Research Highlights

Graphic image of ionospheric behavior during the 2009 SSW event
October 23, 2020

Sudden stratospheric warmings (SSWs) are impressive fluid dynamical events in which large and rapid temperature increases in the winter polar stratosphere (∼10–50km) are associated with a complete reversal of the climatological wintertime westerly winds.

Graphic image showing the maps of the E-region horizontal and radial currents
October 2, 2020

The flow of ionospheric current can be probed by examining magnetic field measurements at the ground and at Low-Earth-Orbit (LEO) altitude.

Graphic image showing polar maps of the simulated electron density
October 2, 2020

During geomagnetic disturbances, enhanced high‐latitude convection transports ionospheric F2‐region plasma from the dayside midlatitude region into the polar cap, leading to structures such as tongues of ionization (TOIs) and patches.

Graphic image showing a portion of the inner penumbra in the MURaM sunspot simulation
October 2, 2020

Recently, there have been some reports of unusually strong photospheric magnetic fields (which can reach values of over 7 kG) inferred from Hinode SOT/SP sunspot observations within penumbral regions.

Graphic image 2D evolution of thermospheric ∑O/N2 response
September 16, 2020

We conduct observational and modeling studies of thermospheric composition responses to weak geomagnetic activity (non-geomagnetic storms). We found that the thermospheric O and N 2 column density ratio (∑O/N 2 ) in part of the Northern Hemisphere measured by

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