Article ID Journal Published Year Pages File Type
1777459 Journal of Atmospheric and Solar-Terrestrial Physics 2011 6 Pages PDF
Abstract

We demonstrate evidence that past composite based studies centred around the onset of Forbush decrease (FD) events may have improperly isolated the maximal galactic cosmic ray (GCR) decrease associated with the FD events. After an adjustment of the composite to account for such shortcomings we find indications of anomalous cloud cover decreases (of around 3%) located in the upper levels of the troposphere at high southern latitudes. These cloud changes are detectable after latitudinal averaging, suggesting the possibility of a second order relationship between the rate of GCR flux and cloud cover in this region. The maximal cloud change is observed in advance of the maximal GCR decrease; this implies that if the observed cloud changes bear a causal relationship to the rate of GCR flux, then cloud properties may be sensitive to changes in GCR conditions rather than the maximal deviations themselves.

Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Geophysics
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