Jiahao Zhong, a passion for mathematics & programming

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Monday, August 15, 2016

Jiahao Zhong is a graduate student visitor at HAO since March 2015. He works with Wenbin Wang and Alan Burns. He is currently a Ph.D. student at University of Science and Technology of China working with Jiuhou Lei. His current research goals are aimed at understanding the topside ionosphere and plasmasphere variability under different geophysical conditions using GNSS total electron content (TEC) data observed by low Earth orbit (LEO) satellites.

Jiahao Zhong image
Jiahao Zhong

Jiahao is from Guangzhou, the capital of Guangdong province in China (third largest Chinese city behind Shanghai and Beijing). Guangzhou is a sprawling port city northwest of Hong Kong on the Pearl River. As a boy he developed a strong love for mathematics and programming; later, he became interested in processing satellite remote sensing data.

As part of Jiahao's Ph.D. program, he researches the retrieval of the absolute LEO-based TEC data. He has assessed the LEO-based mapping function, which is used to convert slant TEC to vertical TEC. He has discovered that the long-term variations of the GPS differential code biases (DCB) are not associated with the ionospheric variability with the LEO-bases data. He has also proposed an improved LEO DCB estimated method and discussed the parameter setting in a least square LEO DCB method. These method improvements are helpful to process highly accurate and reliable LEO-based TEC data.

As a graduate student visitor at HAO, Jiahao has used LEO-based TEC observations from multiple LEO satellites to investigate the local time, altitudinal, and longitudinal dependence of the topside ionospheric storm effect during both the main and recovery phases of the March 2015 geomagnetic storm, and he found that there was a persistent topside TEC depletion that lasted for more than 3 days after the storm main phase at most longitudes. In addition, Jiahao has been working on the longitudinal and latitudinal structures of upward-looking TEC under various conditions of solar flux, altitude, local time and season using upward-looking TEC data observed by two Sun-synchronous-orbit satellites during 2008–2015. In the future, Jiahao will use electron densities, electric fields, neutral winds and neutral composition from the NCAR-TIEGCM simulations to explore the underlying physical processes that are responsible for the variability of the topside ionosphere. In the end of August, Jiahao will complete his program at HAO and return to his home institution. Jiahao will receive his Ph.D. in July 2017.