On the correlation between cosmic ray intensity and cloud cover

TL;DR

This paper analyzes the complex relationship between cosmic ray intensity and cloud cover, suggesting no direct causal link and proposing alternative explanations involving solar activity effects.

Contribution

It provides a detailed analysis showing the lack of direct causality between cosmic rays and low cloud cover, and discusses the influence of solar activity on climate variables.

Findings

No direct causal link between CR and LCC

Anticorrelation between LCC and MCC

Parallel influence of solar activity on temperature and cloud cover

Abstract

Various aspects of the connection between cloud cover (CC) and cosmic rays (CR) are analysed. Many features of this connection indicate that there is no direct causal connection between low cloud cover (LCC) and CR in spite of the evident long-term correlation between them. However, most of these features are indirect. If only some part of the LCC is connected and varies with CR, then its value, obtained from the joint analysis of their 11-year variations, and averaged over the globe, should be most likely less than 20%. The most significant argument against a causal connection of CR and LCC is the anticorrelation between LCC and the medium cloud cover (MCC). The scenario of the parallel influence of the solar activity on the global temperature and CC on one side and CR on the other, which can lead to the observed correlations, is discussed and advocated.