The investigators will develop a prototype of next generation meteor radars with improved ability for deriving neutral winds, temperatures and individual meteor properties. The data will be used to determine a more accurate characterization of the global meteor flux and its effect on upper atmospheric physics. The radar will be operated at a site in Pennsylvania and will be capable of observing at least two of three primary types of meteor reflection: 1) the commonly used specular meteor trails; 2) the recently understood non-specular trails, which result from plasma instability and turbulence generated field aligned irregularities (FAI); and 3) meteor head-echoes, which are a radar target moving at the speed of the meteoroid. Since the system can detect and resolve in time and space at least two mechanisms, we can study the observation biases introduced by each technique. These biases plague our current characterization of the meteor input function into the upper atmosphere, introducing uncertainties in the estimates of atmospheric parameters. Additionally, the detailed radio signature produced by both head echoes and non-specular trails are far more complex than specular echoes. The system will be designed using the latest digital technology, improving the available data for the study of both meteors, and the dynamics and energetics of themesosphere and lower thermosphere (MLT) atmospheric region. The investigators have built strong domestic and international collaborations that will be crucial in achieving the scientific and educational goals of the program. The research will provide undergraduate and graduate students exposure to a wide variety of fields including aeronomy, meteor science, design and construction of radar systems, radio frequency engineering, and software radar.

Project Report

Billions of dust and sand sized meteors strike the Earth's upper atmosphere every day. Yet, information on the basic properties of the global meteor flux, such as average mass, velocity, and chemical composition remain poorly constratined and understood. One of the most reliable and effective means to acquire such global information is by radar remote sensing. This work is an effort to provide new and improved meteor radar sensing capabilities. The goal of this effort was to develop a next generation advanced radar instruments and technologies, with primary objectives of making such instruments more capable and more cost effective. This is the first meteor radar designed to observe all three types of radio scatter form meteor trails, 24-7, 365 days a year. Each type of radio scatter, when combined with modeling and simulation teaches about a different aspect of meteor properties. Key outcomes and discoveries include the education of several undergraduate, graduate students and post-doctoral researchers. The modeling and observation efforts also resulted in several key discoveries: 1. Explaining a long standing mystery on the source of long duration radar meteor trails, lasting several minutes 2. Development and demonstration that meteor trail reflection duration is directly tied to wind velocity. 3. Discovery and demonstration that models can be used to interpret the reflection profile of meteor trails to discern their chemical composition. 4. The suggestion and initial evidence that he meteor iron mediates the carbon cycle in the Southern Ocean These results were widely distributed in journals, conference presentations and news articles.

Agency
National Science Foundation (NSF)
Institute
Division of Atmospheric and Geospace Sciences (AGS)
Application #
1032334
Program Officer
Therese Moretto Jorgensen
Project Start
Project End
Budget Start
2009-07-31
Budget End
2013-05-31
Support Year
Fiscal Year
2010
Total Cost
$66,678
Indirect Cost
Name
Johns Hopkins University
Department
Type
DUNS #
City
Baltimore
State
MD
Country
United States
Zip Code
21218