Layers in the Equatorial Mesosphere (LEMMA)

Project: Research project

Description

Radars in the VHF frequency range (MST radars) frequently observe echoes originating in the mesosphere, i.e. 50 to 90 km altitude. The echoes can be either the result of perturbations in the electron density, or in the neutral atmosphere; the most powerful radar of this kind exists in Jicamarca, Peru. Perturbations, notably of the neutral atmosphere, are thought to be caused by turbulence and are therefore indicative of transport and redistribution of minor atmospheric constituents. Other causes for perturbations of the plasma densities are assumed to be large aerosols or "smoke" particles. In order to disentangle the two possible causes for these echoes, two instrumented sounding rockets will be launched into different types of these echoes. The payloads will carry instruments to establish plasma densites both absolute and in great fine structure detail (on the sub-percent and sub-metre scale), as well as detectors for charged and neutral heavy particles (aerosols) and for high resolution neutral densities. The proposed flights are part of a larger campaign organised by NASA and will be launched from the Peruvian rocket range Punta Lobos in March/April 2004. Previously these mesospheric echoes were only studied in detail at polar latitudes, measurements with corresponding details from equatorial latitudes do not yet exist. The Technical University Graz will provide instruments to establish plasma densities (electrons and ions), but will of course also participate in the eval
StatusFinished
Effective start/end date15/02/0331/01/05