Relationship between Na layer and CNA variations observed at Syowa, Antarctic

• Published in: Earth, Planets and Space
• Main Authors: Tsuda, T. T., Tanaka, Y. -M., Tozu, R., Takizawa, K., Ejiri, M. K., Nishiyama, T., Kawahara, T. D., Nakamura, T.
• Other Authors: Japan Society for the Promotion of Science, Inamori Foundation, JGC-S Scholarship Foundation, Research Grants from Casio Science Promotion Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: Space and Planetary Science; Geology; Antarctic; Antarc*
• Online Access: http://dx.doi.org/10.1186/s40623-020-01335-7; http://link.springer.com/content/pdf/10.1186/s40623-020-01335-7.pdf; http://link.springer.com/article/10.1186/s40623-020-01335-7/fulltext.html

Abstract We have performed a statistical data analysis on relationship between simultaneous Na density data and cosmic noise absorption (CNA) data, which is an indicator for energetic particle precipitation, obtained at Syowa, Antarctic in 2000–2002. It is found that the Na densities around the topside of Na layers (above $$\sim 95 \,\hbox {km}$$ ∼ 95 km height) tended to be smaller when the CNA was larger. The amounts of Na density responses, i.e., Na density decrease or Na loss, were increasing with magnetic local time (MLT) from dusk hours to dawn hours, and those of CNA responses, i.e., CNA increase, were also increasing with MLT. Thus, there were clear negative correlations between the Na density and CNA variations. These results indicate that the Na loss around the topside of Na layer would be induced by the energetic particle precipitation, and its effect would be more severe in dawn hours.