Crystal A. Yelverton

Years participated in RESESS: 2011


An Overview

Academic Affiliation: Elizabeth City State University


Born in Baltimore, Maryland and raised in Petersburg, Virginia, Crystal attends Elizabeth City State University in Elizabeth City, North Carolina. She has always been interested in Geology and decided as early as 6th grade to major in geosciences. When not studying, she is working, volunteering, or having fun with friends.


Is climate change affecting tropical cyclone activity?

Determining the consequences of a warmer climate is a highly important issue in today’s society. This study attempted to determine whether tropical cyclone activity has increased in frequency and intensity due to a warming climate. We developed the null hypothesis that there would not be a detectable increase in tropical cyclone activity due to an increase in sea surface temperature. To test our null hypothesis, we examined sea surface temperatures (SST), storm count (HURdat) data, sediment core grain size data from a tropical lagoon, andcategory 2, 3, 4, and 5 hurricanes, covering time periods over the past 30 to 150y ears. A t-test was used to identify significant trends in the regression lines of the five data sets. The SST data and Category 4 and 5 hurricane data exhibited significant increases over time at the 95% confidence level. In the category 2 and 3 storms, HURdat, and grain size data, we could not reject the null hypothesis of no significant change. We examined a direct correlation between annual SST and annual number of storms per year in the North Atlantic, over more than 100 years. Although this correlation suggested a positive trend, a t-test showed that the correlation coefficient r2 was low, less than 0.2. Our analysis confirmed that tropical Atlantic SST only increased by 0.4oC over a100-year period, perhaps not enough warming to cause a clear increase in tropical cyclone activity.