Synergetic impacts of precursory climate drivers on interannual-decadal variations in haze pollution in North China: A review

North China suffers from severe haze pollution and has received widespread attentions since the winter of 2012. In addition to human activities, climate variability also plays an important role, particularly in the interannual-decadal variations in the number of haze days in North China (HDNC). Many previous studies separately explored numerous preceding climate drivers, including Arctic sea ice, Eurasia snow and soil moisture, sea surface temperature in Pacific and Atlantic and forcing of Tibetan Plateau, but lacked assessment and analysis of the joint effects. In this study, we reviewed their impacts on HDNC and associated physical mechanisms. Beyond that, the synergetic effects were newly revealed by the observations and numerical experiments with fixed emissions. The preceding signals explained approximately 66% of the interannual-decadal variations in HDNC by exciting teleconnection patterns in winter and influencing the local dispersion conditions in North China. Furthermore, some future research directions were identified, such as the subseasonal variations in HDNC, subseasonal-seasonal prediction of haze by numerical climate models, and changing relationships between HDNC and climate conditions. (C) 2020 The Author(s). Published by Elsevier B.V.