Chao Xiong

ST Solar-Terrestrial Sciences

The 2019 Division Outstanding Early Career Scientist Award is awarded to Chao Xiong for outstanding research on space weather effects on the thermosphere and ionosphere.

Chao Xiong was the first to developed a technique for deriving electron density estimates from the K-band ranging system between the two GRACE (Gravity Recovery and Climate Experiment) satellites. This provided him with a unique and practically calibration-free data set from the topside ionosphere over the whole GRACE mission period (2002-2017). Together with CHAMP (Challenging Minisatellite Payload) data he employed it in many innovative studies, e.g. checking the validity of the IRI (International Reference Ionosphere) model shedding light on the causes for the Weddell Sea ionisation anomaly or for determining the tidal signature in the topside ionosphere. As recognition for his outstanding studies he was awarded Research Fellow of the Alexander von Humboldt Foundation. Later on he provided comprehensive studies of the tidal signatures of thermospheric mass density and winds and eluded the effect of disturbance winds during geomagnetic storms on the ionospheric dynamics. His profound knowledge and skills enabled him to develop a model for auroral oval boundaries, CH-Aurora-2014, based on field-aligned signatures. This model has great potential for space weather applications. More recently he has focused on disturbances of GPS signal. He is the first to determine clear conditions of ionospheric irregularities that lead to signal dropouts at ESA’s Swarm satellites. This publication, highlighted in the Eos magazine, has become the basis for further studies on specifying the risks of GPS signal disturbances. He is a worthy winner of the ST Division Outstanding Early Career Scientists Award.