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Abstract This study quantifies the contributions of tropical sea surface temperature (SST) variations during the boreal warm season to the interannual-to-decadal variability in tropical cyclone genesis frequency (TCGF) over the Northern Hemisphere ocean basins. The first seven leading modes of tropical SST variability are found to affect basinwide TCGF in one or more basins, and are related to canonical El Niño–Southern Oscillation (ENSO), global warming (GW), the Pacific meridional mode (PMM), Atlantic multidecadal oscillation (AMO), Pacific decadal oscillation (PDO), and the Atlantic meridional mode (AMM). These modes account for approximately 58%, 50%, and 56% of the variance in basinwide TCGF during 1969–2018 over the North Atlantic (NA), northeast Pacific (NEP), and northwest Pacific (NWP) Oceans, respectively. The SST effect is weak on TCGF variability in the north Indian Ocean. The SST modes dominating TCGF variability differ among the basins: ENSO, the AMO, AMM, and GW are dominant for the NA; ENSO and the AMO for the NEP; and the PMM, interannual AMO, and GW for the NWP. A specific mode may have opposite effects on TCGF in different basins, particularly between the NA and NEP. Sliding-window multiple linear regression analyses show that the SST effects on basinwide TCGF are stable in time in the NA and NWP, but have strengthened since the 1990s in the NEP. The SST effects on local TC genesis and occurrence frequency are also explored, and the underlying physical mechanisms are examined by diagnosing a genesis potential index and its components.
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This content will become publicly available on October 28, 2026
Assessment of Tropical Cyclone Activity From a Statistical‐Dynamical Downscaling Model in the Northern Pacific and Atlantic Oceans
Abstract This study investigates the interannual variability of tropical cyclones (TCs) from 1951 to 2019 using observational data sets and synthetic TCs generated by the Columbia HAZard (CHAZ) model, a hybrid TC risk model. Analysis of TC genesis and landfall indicates that CHAZ reasonably captures the spatial distribution of TC activity during the Northern Hemisphere TC season in the tropical western Pacific, eastern Pacific, and Atlantic Ocean basins. The CHAZ simulation of TC genesis, track distribution, and landfall latitude is most accurate in the North Atlantic, where interannual variability is also best represented. Observed interannual correlation coefficients between TC genesis and landfall generally exceed 0.5 in the western Pacific and North Atlantic, but are lower in the eastern Pacific; CHAZ simulates higher correlations across all three basins than observations. Further analysis examines the influence of seven climate modes: El Niño‐Southern Oscillation, Pacific Meridional Mode (PMM), Atlantic Meridional Mode (AMM), Tropical Upper‐Tropospheric Trough in the Pacific (TUTT_Pac) and Atlantic (TUTT_Atl), Western Pacific Subtropical High, and North Atlantic Subtropical High. In the western and eastern North Pacific Ocean basins, heightened TC activity is observed during positive PMM and negative TUTT_Pac phases. In the Atlantic, La Niña, positive AMM, and negative TUTT_Atl phases enhance TC activity. Interactions between modes can amplify or dampen their individual effects; notably, the combination of negative TUTT_Atl and positive AMM phases increases TC landfall occurrence in the Atlantic by over 50% relative to climatological norms in both observations and CHAZ.
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- PAR ID:
- 10664844
- Publisher / Repository:
- American Geophysical Union
- Date Published:
- Journal Name:
- Journal of Geophysical Research: Atmospheres
- Volume:
- 130
- Issue:
- 20
- ISSN:
- 2169-897X
- Page Range / eLocation ID:
- e2025JD043947
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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