Effect of Rossby Waves and Climatic Cycles on Extreme Precipitation in Texas

Abstract

The relationship between extreme precipitation and climatic cycles has been investigated in several regions of the globe. However, the link between extreme precipitation and Rossby wave breaking has received little attention, especially in Texas, which experiences significant floods every year. This study therefore investigated the following questions: How often does Rossby wave (RW) breaking occur in Texas and how severe is it? What is the relationship between RWs and extreme precipitation? What is the effect of El-Niño and La-Niña on extreme precipitation, while RWs are occurring? What is the combined impact of climatic cycles and RWs on extreme precipitation in terms of the number of events and depth of precipitation? To answer these questions, precipitation characteristics (number of rainy days, and duration, depth, and intensity of precipitation) were grouped under different RW frequency zones; it was found that extreme precipitation was primarily affected by the El-Niño–Southern oscillation precipitation index (ESPI) and the southern oscillation index (SOI). The frequency of RW evidently affected precipitation characteristics in Texas. These findings help understand the cause of occurrence of extreme precipitation events with the joint effect of climatic cycles and RW.