Assessing the Ability of Climate Models to Simulate the Observed Sensitivity of Tropical Cyclone Intensity to Sea Surface Temperature

• Other Authors: Strazzo, Sarah E. (authoraut), Elsner, James B. (professor directing dissertation), Fuelberg, Henry E. (university representative), Uejio, Christopher K. (committee member), Zhao, Tingting (committee member), Florida State University (degree granting institution), College of Social Sciences and Public Policy (degree granting college), Department of Geography (degree granting department)
• Format: Text
• Language: English
• Published: Tallahassee, Florida: Florida State University 2015
• Subjects: Climatic changes; Atmospheric sciences; Geography; North Atlantic
• Online Access: https://diginole.lib.fsu.edu/islandora/object/fsu%3A253044/datastream/TN/view/Assessing%20the%20Ability%20of%20Climate%20Models%20to%20Simulate%20the%20Observed%20Sensitivity%20of%20Tropical%20Cyclone%20Intensity%20to%20Sea%20Surface%20Temperature.jpg

This series of studies evaluates the ability of global climate models (GCMs) to simulate the observed relationship between the upper limit of tropical cyclone (TC) intensity and sea surface temperature (SST). Previous studies addressed whether GCMs are capable of reproducing observed TC frequency and intensity distributions. This research builds upon these earlier studies by examining how well GCMs capture physically relevant relationships that are important for understanding the impacts of climate change on TC intensity. The research presented here aims to 1) quantify differences between the observed and simulated sensitivity of TC limiting intensity to SST, and 2) explore possible explanations for any differences that exist. Observed TC data are compared to simulated TCs from four different GCMs---the FSU-COAPS, GFDL-HiRAM, MRI-AGCM, and NCAR-CAM. Model horizontal grid spacing ranges from ~100 km for the FSU-COAPS to ~20 km for the MRI-AGCM. An additional comparison is made for TCs generated through a statistical-deterministic downscaling technique. This research uses a spatial tessellation approach that spatially bins North Atlantic TC and SST data into equal-area hexagon regions. For each region, the statistical upper limit of observed and simulated TC intensity (i.e., limiting intensity) is estimated using extreme value theory. For comparison with the statistical limiting intensity, reanalysis and model field data are employed to approximate observed and simulated potential intensity, respectively. Results reveal that the current suite of GCMs do not capture the observed sensitivity of TC limiting intensity to SST. While a 1° C increase in SST corresponds to a 7.9 +/- 1.19 m/s increase in observed limiting intensity, the same 1° C increase in SST is not associated with a statistically significant increase in simulated TC limiting intensity. This is found to be true both for relatively coarse resolution GCMs that do not generate TCs with intensities exceeding 50 m/s as well as for higher resolution GCMs that ...