Infrared and Ionization Structure of the Polar Mesosphere
Abstract
The primary objective of this project was the investigation of the spatial and temporal structuring and photochemistry of the infrared airglow and the dynamic processes that modify the physical and radiative properties of the polar mesosphere. The approach was to conduct ground-based mesospheric/ stratospheric/tropospheric (MST) radar measurements and rocket-borne probes. Rockets containing dec probes were launched to measure electron density irregularities with high spatial resolution. They were launched at times when the MST radar showed regions of intense backscatter in the mesosphere. Large changes and strong gradients in the electron density were observed in the region of most intense backscatter. Several results from the spectra which are in agreement with present theories are as follows: (1) The electron fluctuation spectrum displayed both a Kolmogorov inertial subrange and a viscous subrange characterized by an inner scale for turbulence. (2) The inner scale size for the electron gas varies with the energy dissipation rate in a manner predicted by classical turbulence theory. (3) The 50 MHz scattering signal is in qualitative agreement with the in situ measurements. Some of the more controversial results we have found are: (1) The microscale for turbulence in the electron gas is much smaller than expected. (2) The electrons seem to behave as a passive scalar but one with a large Schmidt number. (3) The fact that strong high latitude mesospheric scatter occurs at all for a 50 MHz radar is due to the unusual character of the electron spectrum. (4) For weak electron density gradients the electron spectrum has a Kolmogorov form, but for the case of strong gradients, the spectrum is steepened.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1988
- Accession Number
- ADA201266
Entities
People
- Allan J. Steed
- James C. Ulwick
- Kay D. Baker
Organizations
- Utah State University