Phase Shifts of the PDO and AMO Alter the Translation Distance of Global Tropical Cyclones

Abstract

Recent decadal changes in tropical cyclone (TC) frequency since the mid‐1990s have been widely reported; however, it is unclear whether there have also been any changes in TC translation distance. Here, we show that long‐term decrease in global TC translation distance during 1975–2020 is caused by an abrupt change point around the year 1997. This change point marks a switch between an increasing translation distance during 1975–1997 and decreasing translation distance during 1998–2020. The shift in TC translation distance is attributed to changes in the distance between the location of TC genesis and land, and the percentage of landfalling TCs to all TCs, which is driven by the Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO) phase switch in the mid‐1990s. In the last 20 years, the cool, La Niña‐like sea surface temperatures (SST) during the PDO negative phase and the warm SST pattern during the AMO positive phase have enhanced the genesis potential index and the potential intensity in offshore areas, resulting in greater TC genesis landward. Phase shifts of PDO and AMO modulate environmental conditions, regulating TC genesis location and landfall frequency, and their combined effects on the translation distance of Pacific TCs. The warm SST anomalies during the AMO positive phase enhance these circulation patterns in two possible ways: via the Indian Ocean and the subtropical eastern Pacific relaying effects at a multidecadal timescale. Our findings suggest that the PDO and AMO act as key pacemakers for decadal changes in global TC translation distance.

Global Projection of Flood Risk With a Bivariate Framework Under 1.5–3.0°C Warming Levels

“…Figures 3 and 4 illustrate the MME median relative change of flood peak and duration at the return period (RP) of 50‐year from the baseline period (1985–2014) to different future warming periods, presenting large regional heterogeneity at global scale. In most catchments in China, both flood peak and duration are predicted to surge strikingly, which aligns with previous work (Kang et al., 2023). With increasing temperature levels, the growing trend becomes more significant (from approximately 10% of flood peak relative change at 1.5°C warming period to greater than 30% at 3.0°C warming period, Figure 3), implying a potential threat to the existing infrastructure in China.…”

“…Following previous research (Brunner et al., 2019; Kang et al., 2023; Tosunoglu et al., 2020; Vittal et al., 2015), in the extraction of flood characteristics, the annual maximum peak is sampled, while the identification of flood duration is achieved through the utilization of the base flow curve (Figure S1 in Supporting Information S1). Flood magnitudes are often more strongly related to variations in antecedent base flow than short‐term (≤3‐day) extreme precipitation (W. R. Berghuijs & Slater, 2023).…”

“…Numerous studies have utilized bias‐corrected global climate models (GCMs) as inputs to force hydrological models (HMs) for projecting future floods changes (e.g., Kang et al., 2023; Tofiq & Güven, 2015; Yin et al., 2020). The spatial scales of studying flood risk under climate change range from the catchment scale (Ma et al., 2021; T. Wang et al., 2022; Wu et al., 2023) to the regional scale (Lin et al., 2018; Roudier et al., 2016; Sairam et al., 2021).…”

Attribution of the Record‐Breaking Extreme Precipitation Events in July 2021 Over Central and Eastern China to Anthropogenic Climate Change

“…These data in our study regions are available in Wang, Gu, Slater, et al. (2023). Daily precipitation and other meteorological parameters from the CMIP6 are available through https://esgf-node.llnl.gov/search/cmip6/.…”

“…The daily observed gridded precipitation data were obtained from the China Meteorological Data Service Center (http://www.nmic.cn/en) but are currently not available at this website. These data in our study regions are available in Wang, Gu, Slater, et al (2023). Daily precipitation and other meteorological parameters from the CMIP6 are available through https://esgf-node.llnl.gov/search/cmip6/.…”