Recurrent Rossby Wave Packets Modulate the Persistence of Dry and Wet Spells Across the Globe

Persistent dry and wet spells can arise from stationary weather situations or recurrent flow patterns result in significant socio-economic impacts. Here, we study the effects of synoptic-scale transient Rossby wave packets (RRWPs) on persistence using ERA-Interim reanalysis data. RRWPs significantly alter (decrease increase) spell across globe. Spatial statistically links between durations superposition a zonally symmetric component wave-like that is modulated by local factors such as orography position relative to major moisture sources. The apparent during Northern Hemisphere winter dominates Southern signal summer. appears primarily Hemisphere, changes its wavenumber with season thus, conceivably related dynamics.