Overview of Nighttime Ionospheric Instabilities at Low- and Mid-Latitudes: Coupling Aspects Resulting in Structuring at the Mesoscale

• Published in: Space science reviews Vol. 168; no. 1-4; pp. 419 - 440
• Main Authors: Makela, Jonathan J., Otsuka, Yuichi
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2012; Springer; Springer Nature B.V
• Subjects: Aerospace Technology and Astronautics; Astrophysics and Astroparticles; Earth, ocean, space; Exact sciences and technology; Geophysics; Ionosphere; Latitude; Meteorology; Physics; Physics and Astronomy; Planetology; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Mid-latitude ionosphere; Rayleigh-Taylor instability; Low-latitude ionosphere; Perkins instability; Ionospheric irregularities; Mid latitude; Plasma density depression; Growth rate; Seeding; Travelling ionospheric disturbance; Reviews; Mesoscale; Linear theory; Database; Instability; Low latitude; Coupling; Altitude
• ISSN: 0038-6308; 1572-9672
• DOI: 10.1007/s11214-011-9816-6

We present a review of the current state of understanding regarding two classes of irregularities causing mesoscale structuring (hundreds of kilometers) in the nighttime ionosphere at low- and mid-latitudes. Additionally, current state of understanding of equatorial plasma bubbles at low latitudes, and medium-scale traveling ionospheric disturbances at mid latitudes and their relationship to possible seeding from lower altitudes are described. In each case, well-developed linear theories exist to explain the general properties of the irregularities. However, these linear theories have growth rates too low to explain the actual observations, giving rise to the need to invoke seeding mechanisms. We describe the observational databases that have been compiled over the decades and discuss possible coupling and seeding mechanisms that would overcome the low growth rate and explain the observed structuring at the mesoscale. Future research directions are also briefly discussed.