Comprehensive Analysis of the Magnetic Signatures of Small‐Scale Traveling Ionospheric Disturbances,as Observed by Swarm
Abstract
Based on Swarm satellite data from 2015 through 2018, we present the mean characteristics of magnetic field fluctuations at midlatitudes and low latitudes. It is the first comprehensive study focusing on small‐scale variations (2 flow typically between the hemispheres. Return currents are distributed over larger scales and thus have smaller amplitudes. Peak current densities get larger toward lower latitudes. There are two groups of events, around morning‐noontime and evening‐night, which are separated by demarcation lines near 04 and 15 magnetic local time. The magnetic amplitudes of the small‐scale fluctuations are larger in sunlight than in darkness, indicating larger total currents in the loops. But the FAC peak current densities are larger in darkness, inferring a stronger squeezing of the current sheet under low‐conductivity conditions. We suggest that our SSTIDs are an evolutional state of medium‐scale traveling ionospheric disturbances.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 01, 2019
- Source ID
- 10.1029/2019ja027523
Entities
People
- Fan Yin
- H. Lühr
- Jaeheung Park
- Ling Wang
Organizations
- Air Force Office of Scientific Research
- GFZ Helmholtz Centre for Geosciences
- Korea Astronomy and Space Science Institute
- Korea University of Science and Technology
- National Natural Science Foundation of China
- Program 973
- Wuhan University