Abstract
AbstractWe present a study of decameter scale ionospheric irregularities using in‐situ electron density data from the NorSat‐1 satellite. During the current period of low solar activity, NorSat‐1 frequently observes significant plasma irregularities from several 10 s km down to several decameter. These are often observed near the dayside cusp and dawnside auroral zone. The decameter‐scale irregularities are positively correlated with intermediate‐scale (10 km) density gradients, for both negative and positive gradients encountered by the satellite. The statistical distribution of electron density over two winter months in the northern hemisphere along NorSat‐1 orbits, shows significant density increases in the cusp ionosphere (75°–80° Magnetic LATitude) and in regions near the dawnside auroral oval. Intermediate scale density gradients and small‐scale irregularities are clearly associated with these density enhancements. We postulate that these density enhancements and irregularities are due to auroral particle precipitation/plasma dynamics.
Highlights
Plasma irregularities and turbulence are frequently observed in the polar ionosphere
We present a study of decameter scale ionospheric irregularities using in-situ electron density data from the NorSat-1 satellite
The image is presented in Magnetic LATitude (MLAT)/Magnetic Local Time (MLT) coordinates, where the Sun is toward the top and dawn in on the right
Summary
Plasma irregularities and turbulence are frequently observed in the polar ionosphere. Ionospheric irregularities span a wide range in spatial scales, from 10s of km down to meter scales (Tsunoda, 1988 and references therein). We define large-scale structures to have waveleEngths 100 km, intermediate scale E as 1 100 km, and small scaEle as 1 km. The small-scale irregularities at decameter scales have received much attention due to the backscatter of radio signals from high frequency (HF) radars (e.g., Baker et al, 1986). Though the HF backscatter has been observed very early, the first in-situ measurements of HF echoing targets were achieved by the ICI-2 sounding rocket (Moen et al, 2012). Though the HF backscatter has been observed very early, the first in-situ measurements of HF echoing targets were achieved by the ICI-2 sounding rocket (Moen et al, 2012). Moen et al (2012) presented a case study to test the role of Gradient Drift
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
