Reduction and enhancement of dust impact detections made by Wind during SIRs. Top panel: Scaled superposed epoch analysis of the daily number of dust impacts during SIRs as a moving average within a 30 min interval (grey) or a 4 h interval (red). Only the SIRs that are associated with CIRs were taken into account. The shaded red area indicates 95% confidence intervals for a Poissonian distribution. Bottom panel: Histogram of the enhancement or reduction factor of dust impacts for the SIRs that are associated with CIRs. The dashed blue line denotes the average reduction of 20.7%. The five SIRs that begin on 1 January 2005, 23 November 2006, 15 January 2007, 24 November 2008, and 30 August 2009 were excluded due to low number statistics.