APL Colloquium

October 30, 2020

Colloquium Topic: The Persistent Impacts of the 2011 Tohoku Earthquake/Tsunami on Ionospheric Space Weather

On 11 March 2011, a magnitude 9.0 earthquake occurred near the east coast of Honshu, Japan, unleashing a savage tsunami as well as unprecedented plasma ripples at the space‐atmosphere interaction region, i.e., ionosphere. Although the earthquake was a transient local event, the tsunami ocean waves backscattered by seafloor topography in the Pacific Ocean continuously excited gravity waves and planar traveling ionospheric disturbances (TIDs) propagating toward Japan for more than 10 hr. Unusual ionospheric band structures referred to the mid-latitude nighttime medium‐scale TIDs (MSTIDs) and plasma irregularities developed following the planar TIDs over Japan. It is common to observe the nighttime MSTIDs traveling along the Japanese islands during the summer; however, they are rarely seen in March. What drove the appearance of MSTIDs and ionospheric irregularities in March was likely the reflected tsunami wave‐induced gravity waves. Such space weather phenomena have an adverse impact on Global Navigation Satellite System navigation and applications. Therefore, understanding how natural hazards impact our upper atmosphere and cause variations in the space environment around Earth is crucial.

Colloquium Speaker: Min-Yang Chou

Min-Yang Chou is a Postdoctoral Fellow at the University Corporation for Atmospheric Research, COSMIC Program Office, since 2019. He received his Ph.D. from the National Cheng Kung University in Taiwan in 2018. His research interest is understanding how the atmospheric waves affect the ionosphere. His research is conducted using a variety of ground-based and satellite observations and numerical models, such as ground-based GNSS networks, HF Doppler Sounders, FORMOSAT-3/COSMIC, FORMOSAT-7/COSMIC2, GOLD, and SAMI3. He has also developed the ionospheric processing systems for ground-based GNSS receivers and FORMOSAT-3/7 satellite missions for Taiwan National Space Organization. His research currently focuses on understanding the impacts of atmospheric waves on the formation of equatorial ionospheric plasma bubbles.