Remote Effects of IOD and ENSO on Motivating the Atmospheric Pattern Favorable for Snowfall Over the Tibetan Plateau in Early Winter

The interannual variation of snowfall over the Tibetan Plateau (TP) in early winter (November–December) and its related atmospheric attribution are clarified. Meanwhile, influence tropical sea surface temperatures (SSTs) on TP is investigated by diagnostic analyses Community Atmosphere Model (CAM5) simulations. leading mode features a spatially uniform pattern with remarkable variability. It found that Indian Ocean Dipole (IOD) El Niño Southern Oscillation (ENSO) main external forcing factors for snowfall. Positive IOD positive ENSO neutral cases both have remote impact motivating Eurasia (SEA) pattern, which can induce an anomalous cyclone around TP. corresponding ascending motion cold air mid-upper troposphere provide dynamical thermal conditions heavy low-level southwesterly winds enhanced Arabian Sea Bay Bengal, bringing abundant water vapor into excessive Furthermore, CAM5 simulation experiments forced IOD- ENSO-related SST anomalies performed to verify their combined independent effects winter. confirmed either or has certain impacts circulation favorable However, plays role producing snowfall-related conditions, there asymmetric