10/03/2022
By Lynne Schaufenbil
"BALBOA – Unveiling the Secret Covered by Sunlight" by Xiaoyan Zhou from the Earth, Planetary, and Space Sciences Department, University of California, Los Angeles, CA.
Abstract
BALBOA (BALloon-Based Observations for Sunlit Aurora), a pathfinder balloon mission, aims to image aurora under the Sun. The advantages of the NASA balloon altitude include obtaining higher SNR (signal over noise ratio), dayside/sunlit auroras with small-scale structures, little constraint of the atmosphere, and cost efficiency (reusable instruments, etc.) Given that solar wind‐magnetosphere‐ionosphere coupling is initiated on the dayside, the BALBOA science addresses the fundamental questions of the auroral dynamics in dayside and global coupling, such as dayside auroral north-south conjugacy and dayside-to-nightside auroral causality/correlation. Auroral remote sensing is one of the earliest space physics experiments, pioneered by the German physicist Martin Brendel, who took the first successful auroral photographs in 1892. Since then, auroral forms and their dynamics have been acquired only when the aurora is in darkness. The overwhelming daytime sky brightness severely compresses the SNR and challenges all attempts to reveal the secrets veiled by sunlight. The atmospheric MODTRAN model shows that the sky brightness decreases with increasing wavelength and altitude, indicating that the sky background noise can be substantially reduced toward longer wavelength aurora and higher altitude. Modern technologies, such as new semiconductor sensors and scientific ballooning, have provided an opportunity in that direction. We were very much encouraged when the N2+ Meinel band around ~1110 nm was recorded during twilight, which resembles the sky brightness at balloon altitude in Antarctica based on MODTRAN. This presentation briefly reviews auroral mechanisms, new sciences that can be enabled by BALBOA, the project status, and short- and long-term plans.
Xiaoyan Zhou Brief CV
Ph.D. in Space Physics in 1991, the Geophysical Institute of The Chinese Academy of Sciences, Beijing, China. Studied magnetic storm forecasting using neural networks.
1994 – 1995 Research visitor at the Institute of Geophysics and Planetary Physics, UCLA, studied geo-magnetotail
1996 – 1997 Researcher at the Geophysical Institute, The Chinese Academy of Sciences, Beijing, China, studied forecasting methods of geomagnetic activity
1998 – 2013 Research Scientist, Jet Propulsion Laboratory, California Institute of Technology, studied shock aurora, interplanetary shocks, and the solar wind-magnetosphere coupling
2014-present Associate Researcher, Department of Earth, Planetary and Space Sciences, UCLA, studying interplanetary shocks and dayside auroral imaging
If you are interested in attending, please email Lynne_Schaufenbil@uml.edu for the Zoom link.