Global Trends of Tropical Cyclone Intensity Change

Rapid intensification (RI) of tropical cyclones (TCs) has become a concerning trend in recent years and has made hurricane forecasting increasingly difficult as a result. Several studies have been conducted by Klotzbach et al. (2022), Bhatia et al. (2022), Manikanta et. al (2023) in recent years suggesting an overall increasing trend in rapidly intensifying TCs across different ocean basins. Studies also found an increasing rate of intensification from category 1 (CAT1) to major hurricanes (Kishtawal et al. 2012; Wang et al. 2020) during the past 35 years. Wang et al. (2020) also found that the probabilities of RI and rapid weakening (RW) have both risen in the period 2000-2018 compared to 1982-1999. However, both Klotzbach et al. (2022) and Bhatia et. al (2022) did not include tropical depressions (TDs), therefore missing many RI cases that initially began in the TD stage. Their studies had less samples. Similarly, both Kishtawal et al. (2012) and Wang et al. (2020) only studied CAT1-5 hurricanes with life-time maximum intensity of at least CAT2 or CAT3, excluding TDs and tropical storms (TSs).

Therefore, in this study, we plan to analyze 40 years of TC best track data (1982-2022) to determine the long-term trends of TC intensity change. We will include TCs from all initial intensity stages (e.g., TD, TS, and all hurricanes from CAT1 to CAT5) and all global TC-prone basins. We will classify TC intensity change into different categories including RI, slowly intensifying (SI), neutral (N), slowly weakening (SW), and RW. We will compare the trends of TC intensity changes for 6 TC-prone basins: Atlantic (ATL), East Pacific (EPA), Northwest Pacific (NWP), South Pacific (SPA), North Indian (NIO), South Indian (SIO).

References:

• Bhatia, K., Baker, A., Yang, W., Vecchi, G., Knutson, T., Murakami, H., Kossin, J., Hodges, K., Dixon, K., Bronselaer, B., & Whitlock, C. (2022): A potential explanation for the global increase in tropical cyclone rapid intensification. Nature communications. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9636401/

• Kishtawal, C. M., Jaiswal, N., Singh, R. & Niyogi 2012: D. Tropical cyclone intensification trends during satellite era (1986-2010). Geophys. Res. Lett. 39 https://doi.org/10.1029/2012GL051700.

• Klotzbach, P. J., Wood, K. M., Schreck, C. J., Bowen, S. G., Patricola, C. M., & Bell, M. M. (2022). Trends in global tropical cyclone activity: 1990–2021 - klotzbach - 2022 - geophysical research letters - wiley online library. doi/10.1029/2021GL095774

• Manikanta, N. D., Joseph, S., & Naidu, C. V. (2023). Recent global increase in multiple rapid intensification of tropical cyclones. Scientific reports. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10518314/

• Wang, S., Rashid, T., Throp, H. & Toumi, R. A, 2020: Shortening of the Life Cycle of Major Tropical Cyclones. Geophys. Res. Lett. 47, e2020GL088589 (2020).