SPA-GRL Issue Highlights

Espinosa and Dougherty identify periodic perturbations seen in data on Saturn's magnetic field that have hitherto been overlooked. They compare observations from three spacecraft and find the perturbations (a few nanoteslas) in the inbound data from Pioneer 11 and Voyager 2. The authors rule out dipole tilt and current sheet crossings as causes for the perturbation. The period of the perturbation, which is close to Saturn's rotation period, implies a large-scale restructuring of the accepted model of Saturn's magnetosphere as, for example, a ballooning of the magnetic field and plasma.

Litvin et al. analyze St. Santin F-region Incoherent Scatter data for low solar activity and report that nighttime ion temperature is slightly higher than electron temperature due mainly to the neglect of H+ ions in radar spectral analysis. The authors perform a simplified modeling of the ion and electron temperatures with the assumption that the only heat source for both electrons and ions is hot oxygen, and find that just a small amount of hot oxygen is enough to raise both temperatures above the neutral temperature during nighttime. They find good agreement between modeled and data ion temperatures up to 500 km.