Lunar semimonthly signal in cloud amount

TL;DR

This study analyzes satellite data from 1994-2007 to identify lunar influences on cloud cover in Central Russia, confirming that lunar declination and phase significantly affect cloud amount.

Contribution

It provides a detailed separation of lunar phase and declination effects on cloudiness using an extensive satellite dataset, expanding previous research.

Findings

Lunar declination has a stronger effect on cloud amount than lunar phase.

Cloudiness increases near New and Full Moons as lunar phase changes from quadrature.

Both lunar declination and phase effects are statistically significant.

Abstract

Based on NASA satellite infrared and visible range measurements, cloud amount ISCCP_D1 summer nighttime data, representing the tropospheric cloud activity at Central Russia are examined over 1994-2007, and the lunar signal in the cloud amount was extracted. The ISCCP_D1 database was used to confirm previous results of Pertsev, Dalin and Romejko (2007) on the large importance of lunar declination effect compared to the lunar phase effect. Since this database provides much more information than it was used in that previous investigation, it has become possible to separate the lunar phase effect and the lunar declination effect in cloudiness. The relative cloud amount tends to grow with a change of lunar phase from a quadrature to the New Moon or Full Moon and with increasing of the lunar declination by absolute value. The both effects are statistically significant, the second one is a little stronger.