Seasonal Variations in the Strength of Sporadic Meteor Sources Observed by Meteor Radar

Sporadic meteors are a significant source of metals in the Earth's atmosphere and ionosphere, and the understanding of the seasonal variations of their strengths can provide valuable insights into the origins and orbits of cosmic dust particles near Earth. This study analyzes meteor echo data collected by an all-sky interferometric meteor radar in Ledong (LD, 18.4°N, 109.0°E) to quantify the strengths of sporadic meteor sources and their seasonal variations. The results indicate that the helion, antihelion, and apex sources are stronger than the north toroidal source, highlighting a concentration of sporadic meteors near the ecliptic plane and fewer near the ecliptic poles. Distinct seasonal variations are observed, with meteor activity peaking in April and September, likely corresponding to periods of increased meteor and dust particle density in Earth's orbit. Moreover, eight meteor showers are identified as significantly influencing the apparent radiant distributions and have comparable strengths with sporadic meteor sources. To enhance the analysis, a monthly radiant weighting system in ecliptic coordinates is developed, enabling precise calculation of source strengths and improved characterization of seasonal variations in radiant distributions. This research advances our understanding of sporadic meteors and their role in Earth's atmospheric processes, providing a foundation for future investigations into cosmic dust dynamics.