Modeling the seasonal variability of the plasma environment in Saturn's magnetosphere between main rings and Mimas

W. L. Tseng*, R. E. Johnson, M. K. Elrod


研究成果: 雜誌貢獻期刊論文同行評審

16 引文 斯高帕斯(Scopus)


The detection of O2+ and O+ ions over Saturn's main rings by the Cassini INMS and CAPS instruments at Saturn orbit insertion (SOI) in 2004 confirmed the existence of the ring atmosphere and ionosphere. The source mechanism was suggested to be primarily photolytic decomposition of water ice producing neutral O2 and H2 (Johnson et al.; 2006). Therefore, we predicted that there would be seasonal variations in the ring atmosphere and ionosphere due to the orientation of the ring plane to the sun (Tseng et al.; 2010). The atoms and molecules scattered out of the ring atmosphere by ion-molecule collisions are an important source for the inner magnetosphere (Johnson et al.; 2006; Martens et al.; 2008; Tseng et al.; 2010, 2011). This source competes with water products from the Enceladus' plumes, which, although possibly variable, do not appear to have a seasonal variability (Smith et al.; 2010). Recently, we found that the plasma density, composition and temperature in the region from 2.5 to 3.5 RS exhibited significant seasonal variation between 2004 and 2010 (Elrod et al.; submitted for publication). Here we present a one-box ion chemistry model to explain the complex and highly variable plasma environment observed by the CAPS instrument on Cassini. We combine the water products from Enceladus with the molecules scattered from a corrected ring atmosphere, in order to describe the temporal changes in ion densities, composition and temperature detected by CAPS. We found that the observed temporal variations are primarily seasonal, due to the predicted seasonal variation in the ring atmosphere, and are consistent with a compressed magnetosphere at SOI.

頁(從 - 到)126-135
期刊Planetary and Space Science
出版狀態已發佈 - 2013 3月

ASJC Scopus subject areas

  • 天文和天體物理學
  • 空間與行星科學


深入研究「Modeling the seasonal variability of the plasma environment in Saturn's magnetosphere between main rings and Mimas」主題。共同形成了獨特的指紋。