A study on UV emission from clouds with Mini-EUSO

TL;DR

This study investigates how clouds affect space-based UV observations of cosmic ray air showers using Mini-EUSO, analyzing pixel count rates during different cloud conditions to improve future atmospheric monitoring.

Contribution

It demonstrates the potential of Mini-EUSO's UV camera to detect cloud presence by analyzing pixel count rates, aiding atmospheric monitoring for space-based cosmic ray detection.

Findings

Pixel count rates vary with cloud cover and height.

Mini-EUSO can potentially identify clouds using UV data.

Results support integrating UV-based cloud detection in future missions.

Abstract

Mini-EUSO is the first mission of the JEM-EUSO program located on the International Space Station. One of the main goals of the mission is to provide valuable scientific data in view of future large missions devoted to study Ultra-High Energy Cosmic Rays (UHECRs) from space by exploiting the fluorescence emission generated by Extensive Air Showers (EAS) developing in the atmosphere. A space mission like Mini-EUSO experiences continuous changes in atmospheric conditions, including the cloud presence. The influence of clouds on space-based observation is, therefore, an important topic to investigate as it might alter the instantaneous exposure for EAS detection or deteriorate the quality of the EAS images with consequences on the reconstructed EAS parameters. For this purpose, JEM-EUSO is planning to have an IR camera and a lidar as part of its Atmospheric Monitoring System. At the same time, it would be extremely beneficial if the UV camera itself would be able to detect the presence of clouds, at least in some specific conditions. For this reason, we analyze a few case studies by comparing the pixel count rates from Mini-EUSO during orbits with the cloud cover (as cloud fraction). This quantity is retrieved from the Global Forecast System (GFS) model at different height levels over the Mini-EUSO trajectory. The results of this analysis are reported.