Impacts of different El Niño events on winter snowfall over the Tibetan Plateau

The El Niño-Southern Oscillation (ENSO) and snowfall over the Tibetan Plateau (TP) are key factors influencing interannual climate variability, and the relationship between ENSO and TP snowfall exhibits interdecadal variability. However, the types of El Niño events have undergone changes around 2000s, and it remains unclear whether these changes in El Niño event types influence the relationship with snowfall. In this study, we examine the relationship between El Niño events and winter snowfall over the TP using HadISST, and ERA5 reanalysis datasets as well as numerical experiments. Our results show the eastern Pacific El Niño (EPE) events are typically linked to positive winter snowfall anomalies over the TP, while the mixed-type El Niño (MPE) events are associated with negative anomalies, whereas the response of winter snowfall during the central Pacific El Niño (CPE) events exhibits considerable uncertainty. EPE events are associated with an anomalous deepening of the East Asian winter trough, while MPE events typically induce an anomalous atmospheric circulation wave pattern from the North Pacific to the TP, thereby altering the winter temperature structure and winter snowfall over the TP. This study highlights the impact of EPE and MPE events on TP snowfall and provides insights into the underlying atmospheric processes, offering a foundation for future research on their broader climatic implications.