# Solar cycle variation in meteor rates

## TL;DR

This study analyzes 16 years of meteor radar data to reveal that meteor rates are negatively correlated with solar activity, with higher solar activity leading to fewer observable meteors due to atmospheric heating effects.

## Contribution

It provides the first long-term analysis linking meteor rates with solar and geomagnetic activity, highlighting the impact of atmospheric conditions on meteor observations.

## Key findings

- Meteor rates decrease by up to 30% during solar maximum.
- A strong negative correlation exists between solar activity and meteor rates.
- Geomagnetic activity has a smaller, less consistent effect on meteor rates.

## Abstract

Sixteen years of meteor radar data from the Canadian Meteor Orbit Radar (CMOR) were used to investigate the link between observed meteor rates and both solar and geomagnetic activity. Meteor rates were corrected for transmitter power and receiver noise, and seasonal effects were removed. A strong negative correlation is seen between solar activity, as measured with the 10.7 cm flux, and observed meteor rates. This lends support to the idea that heating in the atmosphere at times of elevated solar activity changes the scale height and therefore the length and maximum brightness of meteors; a larger scale height near solar maximum leads to longer, fainter meteors and therefore lower rates. A weaker negative correlation was observed with geomagnetic activity as measured with the $K$ index; this correlation was still present when solar activity effects were removed. Meteor activity at solar maximum is as much as 30\% lower than at solar minimum, strictly due to observing biases; geomagnetic activity usually affects meteor rates by less than 10 percent.