Latitudinal and seasonal variability of the micrometeor input function: A study using model predictions and observations from Arecibo and PFISR |
| |
| Authors: | JT Fentzke D Janches JJ Sparks |
| |
| Institution: | 1. Department of Aerospace Engineering, University of Colorado, Boulder, CO 80301, USA;2. NorthWest Research Associates Inc., CoRA Division, 3380 Mitchell Lane, Boulder, CO 80301, USA;3. Department of Physics, University of Colorado, Boulder, CO 80301, USA;1. CoRA, NWRA, Boulder, CO 80301, USA;2. SRI International, Menlo Park, CA 94025, USA;3. SRI International, Menlo Park, CA 94025, USA;4. MIT Haystack Observatory, Westford MA 01886, USA;1. Saint-Petersburg State University of Aerospace Instrumentation, 67, Bolshaya Morskaya street, Saint-Petersburg 190000, Russia;2. Institute for Physics, Southern Federal University, Stachki, 194, Rostov-on-Don 344090, Russia;3. Physical Department, Southern Federal University, Sorge, 5 Rostov-on-Don 344090, Russia;4. SCiESMEX, Instituto de Geofisica, Unidad Michoacan, Universidad Nacional Autonoma de Mexico, Morelia, Michoacan, CP 58190, Mexico;5. Arctic and Antarctic Research Institute, 38 Bering street, Saint-Petersburg 199397, Russia;1. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Troitsk Region, Moscow 142190, Russia;2. Western Department of Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Kaliningrad, Russia;1. Università degli Studi di Padova, Dipartimento di Matematica “Tullio Levi-Civita”, Via Trieste, 63 - 35121 Padova, Italy;2. Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Blvd de l’Observatoire, CS 34229, 06304 Nice cedex 4, France |
| |
| Abstract: | In this work, we use a semi-empirical model of the micrometeor input function (MIF) together with meteor head-echo observations obtained with two high power and large aperture (HPLA) radars, the 430 MHz Arecibo Observatory (AO) radar in Puerto Rico (18°N, 67°W) and the 450 MHz Poker flat incoherent scatter radar (PFISR) in Alaska (65°N, 147°W), to study the seasonal and geographical dependence of the meteoric flux in the upper atmosphere. The model, recently developed by Janches et al. 2006a. Modeling the global micrometeor input function in the upper atmosphere observed by high power and large aperture radars. Journal of Geophysical Research 111] and Fentzke and Janches 2008. A semi-empirical model of the contribution from sporadic meteoroid sources on the meteor input function observed at arecibo. Journal of Geophysical Research (Space Physics) 113 (A03304)], includes an initial mass flux that is provided by the six known meteor sources (i.e. orbital families of dust) as well as detailed modeling of meteoroid atmospheric entry and ablation physics. In addition, we use a simple ionization model to treat radar sensitivity issues by defining minimum electron volume density production thresholds required in the meteor head-echo plasma for detection. This simplified approach works well because we use observations from two radars with similar frequencies, but different sensitivities and locations. This methodology allows us to explore the initial input of particles and how it manifests in different parts of the MLT as observed by these instruments without the need to invoke more sophisticated plasma models, which are under current development. The comparisons between model predictions and radar observations show excellent agreement between diurnal, seasonal, and latitudinal variability of the detected meteor rate and radial velocity distributions, allowing us to understand how individual meteoroid populations contribute to the overall flux at a particular location and season. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
