Suppression of convective precipitation by elevated man-made aerosols is responsible for large-scale droughts in north China

It has been proposed that the summer “South Flood–North Drought” (SFND) pattern observed in China over recent decades is caused by the relative impacts of global warming, aerosol loading, and natural variability on regional rainfall (1⇓–3). This conclusion is supported by a recent study by Day et al. (4) in which the SFND is attributed to the changes in the frequency of frontal rain events. Using a technique called the Frontal Rain Event Detection Algorithm for the observations during 1951–2007, decadal changes in the amount and distribution of rainfall in eastern China were found to be overwhelmingly due to changes in frontal rainfall (4). Day et al. conclude that frontal rainfall was envisioned as the product of large-scale frontal convergence and the nonfrontal rainfall was because of local convection, orographic rainfall, and typhoon rainfall. The authors further imply that the shifts in frequency and latitude of frontal rainfall over the recent decades in eastern China reflect changes in large-scale atmospheric circulation