Records of sunspot and aurora during CE 960-1279 in the Chinese chronicle of the Song dynasty

TL;DR

This study compiles and analyzes historical Chinese records of sunspots and auroras from the Song dynasty (960-1279 CE) to understand past solar activity and space weather events, providing valuable data for solar research.

Contribution

It presents the first comprehensive survey of sunspot and aurora records from the Songshi chronicle, linking historical observations with modern solar activity indicators.

Findings

Frequency of aurora observations correlates with solar activity periods.

Records of large sunspots and low-latitude auroras indicate extreme space weather events.

Comparison with radioisotope data supports the historical observations' relevance.

Abstract

Records of sunspots and aurora observations in pre-telescopic historical documents can provide useful information about solar activity in the past. This is also true for extreme space weather events, as they may have been recorded as large sunspots observed by the naked eye or as low-latitude auroras. In this paper, we present the results of a comprehensive survey of records of sunspots and auroras in the Songshi, a Chinese formal chronicle spanning the tenth to the thirteenth century. This chronicle contains a record of continuous observations with well-formatted reports conducted as a policy of the government. A brief comparison of the frequency of observations of sunspots and auroras and the observations of radioisotopes as an indicator of the solar activity during corresponding periods is provided. This paper is the first step of our project in which we survey and compile the records of sunspots and aurora in historical documents from various locations and languages, ultimately providing it to the science community as online data.