Meteor-Speed-Variations-analysis

Code and data for Wu JGR 2024: Diurnal and Seasonal Variations of Meteor Speed and Arrival Angle Observed by Mengcheng Meteor Radar.

Citation:

Wu, K., Yi, W., Xue, X., Reid, I., & Lu, M. (2024). Diurnal and Seasonal Variations of Meteor Speed and Arrival Angle Observed by Mengcheng Meteor Radar. Journal of Geophysical Research: Space Physics, 129, e2024JA032767. https://doi.org/10.1029/2024JA032767

Key Points:

• The meteor speed peaks northward in the local morning and shifts clockwise to southward by local evening

• Meteor speed distribution has two Gaussian peaks at ∼28 and ∼54 km/s, revealing semi-annual and annual variation cycles, respectively

• Major meteor showers occur with 45%–97% higher counts than the background, and are associated with increases in the peak speeds

Correspondence to:

W. Yi and X. Xue, yiwen@ustc.edu.cn; xuexh@ustc.edu.cn

Data

Data Availability Statement The Mengcheng meteor radar data presented in this work is available at Wu et al. (2023): Wu, K., Yi, W., Xue, X., Reid, I., & Lu, M. (2023). Data of Mengcheng meteor velocity (version 0) [Dataset]. Zenodo. https://doi.org/10.5281/zenodo.8002780

Keywords and subjects

meteor velocity, meteor radar, meteor shower

Code

The code is in this repository.

The code in this repository is established on and should be run together with nhindley/acp-2021-981: Analysis and Figure code for ACP publication acp-2021-981 Hindley et al., (2022) https://zenodo.org/records/6819061

Abstract

Meteor speed is crucial in identifying key astronomical aspects of the meteoroid environment, including the influx of meteoric material and the distribution of meteoric radiants. This study investigates diurnal and seasonal variations of meteor speed from April 2014 to December 2023 observed by the Mengcheng meteor radar (MCMR; 33.4°N, 116.3°E). In addition to the expected diurnal variation of meteor speed, azimuth peak, zenith peak, and the azimuthal direction of maximum meteor speed due to the Earth's rotation, where the meteor speed peaks northward in the local morning and shifts clockwise, we find that the meteor speed distribution resembles a superposition of two Gaussian distributions, with the lower (higher) distribution mainly ranging from 20 to 40 (45–65) km/s. The two speed peaks are estimated using a double-Gaussian fitting approach. In terms of seasonal variation, we find that (a) the low-speed peak indicates a semi-annual variation cycle, with maxima in June–July and December–January, and minima in February and August; (b) the high-speed peak indicates an annual variation cycle, with maxima in September–December and minima in March. There is also a correlation between the seasonal variations in the meteor speed peaks and the occurrence of meteor showers. Statistical analysis provides a map of seasonal variations in the intensity, duration, and timing of meteor shower activities, which is supplemental to previous shorter-duration studies using backscatter meteor radar observations. We also find notable shower events where the meteor counts exceed 45%–97% of the background count on corresponding event dates and speeds.

Plain Language Summary

Meteor speed plays a crucial role in understanding the quantity and distribution of meteoroids in our environment, yet there are limited observations and investigations conducted at mid-latitudes. In this study, we utilized a meteor radar located in Mengcheng (in the northern lower middle latitudes) to investigate diurnal and seasonal variations in meteor speed from April 2014 to June 2023. Our findings revealed that meteor speed is generally faster in the morning and slower in the afternoon and evening, and the angle of arrival of meteors varies with local time. Additionally, we discovered that meteor speed exhibits two peaks, with the lower one at about 28 km/s and the higher one at 54 km/s. Seasonal changes indicated a semi-annual variation cycle in the low-speed peak and an annual variation cycle in the high-speed peak. Furthermore, we observed several noteworthy meteor showers and their interannual variations.

Acknowledgments

This work is supported by the National Key Technologies R&D Program of China (Grant 2022YFF0503703); the Project of Stable Support for Youth Team in Basic Research Field, Chinese Academy of Sciences (CAS; YSBR‐018); the National Natural Science Foundation of China (Grant 42125402 and 42174183); the B‐ type Strategic Priority Program of CAS (Grant XDB41000000); the Chinese Meridian Project; the Fundamental Research Funds for the Central Universities; the Joint Open Fund of Mengcheng National Geophysical Observatory (MENGO‐202407); and the Open Research for Innovation Challenge (ORIC) Program of X‐Institute. This research was supported by the International Space Science Institute (ISSI) in Bern, through ISSI International Team project #23–580 “Meteors and phenomena at the boundary between Earth's atmosphere and outer space.” We acknowledge the technical support of our radar systems by Chris Adami. We also express our gratitude to Jingnan Guo and Shiyuan Wang at USTC; Quanshui Zheng, Shaohua Xiang, Luping Xu, Jianxun Ren, and Liwen Jing at X‐Institute for their valuable discussions.