Liying Qian

NASA Features Research by HAO Scientist Xuguang Cai

Satellite with spectrograph instrumentation hovering over the earth

Since 2017, HAO has provided scientific support and analysis for NASA's Global-scale Observations of the Limb and Disk (GOLD).

Climate Changes in the Upper Atmosphere: Contributions by the Changing Greenhouse Gas Concentrations and Earth's Magnetic Field From the 1960s to 2010s

Graph depicting Simulated thermosphere and ionosphere temperatures at 300 km in the 1960s
Wednesday, June 23, 2021

Previous studies have established the importance of the increasing greenhouse gas concentrations in causing trends in the thermosphere and ionosphere (T-I). Recent work indicates that the changing Earth’s magnetic field is also important.

Geospace response to an extreme solar flare

Solar flare effects on magnetospheric convection and ionospheric potential.
Friday, June 18, 2021

Solar flares—a sudden eruption of electromagnetic radiation at the Sun—are known to have significant impacts on Earth’s upper atmosphere and ionosphere, but their collective effects on geospace as an integrated system have never been examined.

Variations in thermosphere composition and ionosphere total electron content under ‘geomagnetically quiet’ conditions at solar-minimum

Tie-GCM Graphic
Friday, May 28, 2021

We conducted observational and modeling studies of thermospheric composition and ionospheric total electron content (TEC) variations during two geomagnetically quiet periods (maximum Kp=1.7) at solar minimum.

Investigation of a neutral ‘tongue’ observed by GOLD during the geomagnetic storm on May 11,2019

Latitude-longitude distribution of percentage difference
Tuesday, May 4, 2021

The National Aeronautics and Space Administration Global-scale observations of the Limb and Disk (GOLD) mission observed a unique structure of thermospheric column density ratio of O to N2 (∑O/N2) during a geomagnetic storm on day of year (DOY) 130 (May 10) to DOY 132 in 2019.

Responses of the Thermosphere and Ionosphere System to Concurrent Solar Flares and Geomagnetic Storms

Graphic depicting simulated vertical E x B drift velocity
Wednesday, July 1, 2020

We conducted numerical simulations to examine dayside thermosphere and ionosphere responses to concurrent solar flares and a geomagnetic storm during September 6th – September 11th, 2017, as well as the interplay of flare and storm effects.

Solar Flare and Geomagnetic Storm Effects on the Thermosphere and Ionosphere During 6–11 September 2017

Graphic plots depicting data from Swarm A and Swarm B satellites
Friday, March 29, 2019

The period of September 6 – 11, 2017 was an active period in which multiple solar flares and a major geomagnetic storm occurred. The two largest flares, an X9.3 and an X8.2 flares, were a disk flare and a limb flare, respectively.

Trends and Solar Irradiance Effects in the Mesosphere

Monthly mean global average temperatures graph
Friday, March 29, 2019

We investigate trends and solar irradiance effects in the mesosphere using the Whole Atmosphere Community Climate Model with eXtended thermosphere and ionosphere (WACCM‐X) and radar measurements of winds at Collm (51°N, 13°E), for the period of 1980–2014.

Ionospheric Electron Content during Solar Cycle 23

Comparison of measured to modeled global total electron content
Tuesday, March 13, 2018

Solomon & Qian show that solar minima are not all the same, and may have implications for understanding the Sun during the extended periods of very low activity known as “grand minima” that have sometimes occurred in the past, the best known of which was the Maunder Minimum during 1650–1700.

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