Estimating the Effects of Climate Change on Tropical Cyclone Activity

• Other Authors: Seitz, Chana (authoraut), Misra, Vasu (professor co-directing thesis), LaRow, Timothy (professor co-directing thesis), Hart, Robert (committee member), Sura, Philip (committee member), Department of Earth, Ocean and Atmospheric Sciences (degree granting department), Florida State University (degree granting institution)
• Format: Text
• Language: English
• Published: Florida State University
• Subjects: Earth sciences; Oceanography; Atmospheric sciences; Geophysics; Sura; North Atlantic
• Online Access: http://purl.flvc.org/fsu/fd/FSU_migr_etd-8885; http://fsu.digital.flvc.org/islandora/object/fsu%3A185317/datastream/TN/view/Estimating%20the%20Effects%20of%20Climate%20Change%20on%20Tropical%20Cyclone%20Activity.jpg

The effects of two different future warming climate scenarios on Global and North Atlantic named tropical cyclone (NTC) activity is examined using the Florida State University/Center for Ocean-Atmospheric Prediction Studies (FSU/COAPS) atmospheric general circulation model (AGCM). The two warming scenarios are based on the Representative Concentration Pathways (RCPs) 2.6 and 8.5 from the Coupled Model Intercomparison Project phase 5 (CMIP5). Previously published studies show that the FSU/COAPS AGCM has statistically significant skill at reproducing the observed interannual variability of NTC and hurricane counts in the North Atlantic basin given observed sea surface temperatures (SSTs). In this study, the FSU/COAPS model is forced with monthly varying annual climatological bias-corrected SSTs derived from the CCSM4 model's RCP2.6 and RCP8.5 simulations. In addition, the model's CO2 concentration is modified to reflect the average CO2 concentration over the 2006&ndash2100 time period. For each warming experiment, a 14 member ensemble is made to develop the NTC statistics. In addition, a 14 member control experiment is performed using observed climatological SSTs from the Hadley Centre. An objective detection/tracking algorithm is used to identify and track the NTCs from the model output. For the North Atlantic, a statistically significant increase (14.9%) in the NTC frequency for the RCP2.6 scenario compared to the control experiment is projected by the model. It is also found that with increasing SSTs and CO2 concentration, the North Atlantic NTC intensity (as determined by the NTC maximum 10-m wind speed) and daily storm-centered precipitation also increase. NTC genesis is found to move away from regions of increasing vertical wind shear and decreasing mid-level relative humidity for both future warming climate scenarios. Differences in the track densities between the warming experiments with the control experiment show an increase in landfall potential in the Southeast United States. A Thesis submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the requirements for the degree of Master of Science. Spring Semester, 2014. March 18, 2014. Climate Change, Tropical Cyclone Includes bibliographical references. Vasu Misra, Professor Co-Directing Thesis; Timothy LaRow, Professor Co-Directing Thesis; Robert Hart, Committee Member; Philip Sura, Committee Member.