An Unknown Maximum Lag-Correlation Between Rainfall and Aerosols at 140–160 Minutes

Rainfall and aerosols play major roles in the Earth climate system and substantially influence our life. Here, the focus is on the local near-surface aerosol/rainfall correlations with time scales of minutes to days. We investigated 29 experiments including 14 specific rain events, with time resolutions of daily and 60, 30, and 10 min at 10 stations in Israel and California. The highest negative correlations were consistently at a positive lag of about 140–160 min where a positive lag means that the aerosol time series follows that of the rain. The highest negative value is suggested to be the probable outcome of immediate scavenging along with the rise in aerosol concentration after rain depending on aerosol sources, hygroscopic growth, and transport. The scavenging dominance is expressed by the mostly negative lag-correlation values in all experiments. In addition, the consistent lack of significant correlation found at negative lags suggests a weak aerosol effect on precipitation.