The Role of Nonlinear Energy Advection in Forming Asymmetric Structure of ENSO Teleconnections Over the North Pacific and North America

Abstract

In boreal winter, the El Niño/Southern Oscillation (ENSO)‐induced Pacific‐North American (PNA) teleconnection pattern is farther westward during La Niña relative to that in El Niño, causing discernible distinct climate implications. However, there has been a lack of consensus regarding the underlying mechanism driving this asymmetric structure. This study highlights the contribution of nonlinear kinetic energy advection (nKA) to this asymmetry. The zonally symmetric responses to ENSO, specifically the anomalies in zonal mean zonal flow, generate opposing nKA patterns by advecting anomalous eddy kinetic energy in the North Pacific, which leads to the shift of the PNA teleconnection pattern. In addition to nKA, transient eddy activities responded to changes of baroclinicity help maintain the asymmetry through a feedback effect. These findings underscore the importance of considering extratropical factors, such as nonlinear energy processes and synoptic‐scale transient eddies, in understanding the mechanism responsible for the asymmetric structure of the PNA teleconnection pattern.

A multivariate probabilistic framework for tracking the regional tropical edges: analysis of inter-annual variations and long-term trends

“…These modes are also recognized as drivers of RTE change, with their own distinct geographical contributions. Besides, the North Atlantic Oscillation (NAO) and the Pacific-North American teleconnection (PNA) have the potential contributions to RTE change, as that they have significant variability and are important to regional climate (Loon and Rogers 1978, Horel and Wallace 1981, Hoerling et al 1997, Wang et al 2021, 2023, Li et al 2023a. To better understand their complex interplay, the global RTE are divided into 12 regions with six regions in each hemisphere according to the regional feature of inter-annual variability and long-term trend in section 3.2, and their interaction with the seven climate modes and the significant results are summarized in figure 4 The partial correlation coefficients between the seven climate mode indices and RTE locations over the six regions in the NH and SH are summarized in supplemental tables S2 and S3, respectively.…”

Glo3DHydroClimEventSet(v1.0): A global‐scale event set of hydroclimatic extremes detected with the 3D DBSCAN‐based workflow (1951–2022)

“…On the global scale, compound weather and climate events, a spatial or temporal combination of multiscale natural hazards related to precipitation and temperature extremes, have posed notably non-negligible climate risks (Feng et al, 2022;Ridder et al, 2020;Zscheischler et al, 2018Zscheischler et al, , 2020Zscheischler & Seneviratne, 2017). In particular, a combination of meteorological droughts, extreme precipitations, heatwaves or cold surges has recently drawn much attention, with the increasingly terrible social-economic impacts of global warming (Chiang et al, 2021;Mazdiyasni & AghaKouchak, 2015;Mukherjee & Mishra, 2021;Vogel et al, 2020) and the modulation of multiscale El Niño/La Niña events (Wang et al, 2021(Wang et al, , 2023aZhong et al, 2023). Previous studies have investigated at least two specific categories as follows.…”