Attribution Studies of North Atlantic Hurricane Activity (Invited Presentation)

In this talk I will give an overview of three different methods to examine the attribution of different aspects of North Atlantic hurricane activity to anthropogenic forcing. First, I will discuss the analysis of Trenary et al. (2019), which used discriminant analysis to determine if the observed changes in North Atlantic hurricane potential intensity (PI) can be attributed to greenhouse gases. Trenary et al. showed that currently we cannot yet attribute the changes in Atlantic PI to human-related forcing. However, as greenhouse (GHG) concentrations continue to increase, an unequivocal forced response of North Atlantic PI may emerge in the future. Second, the results of Ting et al. 2019 will be discussed, using a signal-to-noise maximizing analysis to separate the natural and forced component of the vertical wind shear (VWS) and sea-surface temperature (SST). Ting et al. showed that the VWS dipole pattern between the U.S. East Coast and the tropical Atlantic main development region is mostly driven by natural decadal variability. GHG forcing erodes this pattern and the protection of U.S. coast, which in the future could potentially allow hurricanes approaching the U.S. coast to intensify more rapidly. In the third part of the talk, I’ll discuss recent results using synthetic hurricane tracks generated by Columbia Hazard (CHAZ) model (Lee et al. 2018) in combination with observations to detect the climate change signal in hurricane Atlantic activity in the 20^th century.

References:

• Lee C.-Y.., M.K. Tippett, A.H. Sobel, and S.J. Camargo, 2018. An environmentally forced tropical cyclone hazard model. J. Adv. Model. Earth Sys., 10, 233-241, doi: 10.1002/2017MS001186.
• Ting, M., J.P. Kossin, S.J. Camargo, and C. Li, 2019. Past and future hurricane intensity change along the U.S. East coast. Sci. Rep., 9, 7795, doi: 10.1038/s41598-019-44252-w.
• Trenary, L., T. DelSole, S.J. Camargo, and M.K. Tippett, 2019. Are midtwentieth century forced changes in North Atlantic hurricane potential intensity detectable? Geophys. Res. Lett., 46, 3378-3386, doi: 10.1029/2018GL081725.