Short-term Effects of Gamma Ray Bursts on Earth

TL;DR

This paper investigates the short-term atmospheric and biospheric impacts of gamma ray bursts on Earth, focusing on ultraviolet flashes and considering different atmospheric oxygen levels across Earth's history.

Contribution

It introduces a model for assessing gamma ray burst effects on Earth's atmosphere and biosphere across various oxygen levels, highlighting potential ecological impacts.

Findings

Ultraviolet flashes from gamma ray bursts could significantly affect early Earth's biosphere.

The impact varies with atmospheric oxygen levels, being more severe in low-oxygen atmospheres.

Strategies for estimating ecological consequences are proposed.

Abstract

The aim of the present work is to study the potential short-term atmospheric and biospheric influence of Gamma Ray Bursts on the Earth. We focus in the ultraviolet flash at the planet's surface, which occurs as a result of the retransmission of the $\gamma$ radiation through the atmosphere. This would be the only important short-term effect on life. We mostly consider Archean and Proterozoic eons, and for completeness we also comment on the Phanerozoic. Therefore, in our study we consider atmospheres with oxygen levels ranging from $10^{-5}$ to 1% of the present atmospheric level, representing different moments in the oxygen rise history. Ecological consequences and some strategies to estimate their importance are outlined.