Climatological Analysis of Rossby Wave Breaking and Tropcial Cyclone Activity on Seasonal, Intra-Seasonal, and Decadal Timescales

This analysis investigates the relationship between Rossby wave breaking (RWB) and tropical cyclone (TC) activity on a variety of timescales in the northern hemisphere (NH). This will be done through a time series analysis between wave breaking extent, TC activity, and climate modes of variability. The relationship between wave breaking and TC activity has previously been done on a case-by-case basis, but it has not yet been done on a climatological basis. This analysis will focus on the wave breaking events between 1960 and 2011 to determine if there is a relationship between wave breaking and TC activity. By focusing on the NH winter, the peak of the wave breaking season will be captured, and the second half of the TC season in the NH will be observed. This analysis examines the relationship between wave breaking and TC activity on the intra-annual and decadal timescales as well. Additionally, different climate modes of variability will be examined to see if they have any regulating influence on the relationship between TCs and wave breaking. This study focuses on determining if there is a relationship between RWB and TC activity. It was shown that there are significant relationships between wave breaking and TC activity on the seasonal, intra-seasonal, and decadal timescales, and some of the climate modes of variability can have a regulating influence on these relationships. Because of the techniques used, we can only speculate on the mechanisms that are controlling the relationships. Through this analysis, there is a relationship between RWB and TC activity in the NH, and different climate modes of variability can act as a regulating influence on their relationship. Additionally, there appears to be a long-term trend to RWB across the NH.