How Small Scale E Region Irregularities Evolve and Local Implications for the Atmosphere
Abstract
On scales ranging from cm to 100 m in size, the presence of positive feedback mechanisms is able to greatly enhance the magnitude of initially small amplitude structures. The growth associated with these plasma instabilities is such as to accelerate the return to equilibrium conditions. If currents are the main driver, the main role of the short scale irregularities is to somehow reduce the currents. If density gradients are the main driver, the irregularities accelerate ordinary diffusive processes by introducing mixing. The structures also change the conductivity of the medium both directly through the introduction of anomalous diffusion and indirectly through enhancements in electron collision frequencies triggered via electron heating by plasma waves. The electron heating itself is a manifestation of an increase in the Joule heating rate. In this talk I will review the current state of the linear, quasilinear and intermittency theories, relate these theories to some of the numerical simulations, and connect the processes to the conductivity and Joule heating rate problems.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFMSA21C..02S
- Keywords:
-
- 0358 Thermosphere: energy deposition;
- 2407 Auroral ionosphere (2704);
- 2411 Electric fields (2712);
- 2427 Ionosphere/atmosphere interactions (0335);
- 3369 Thermospheric dynamics (0358)