Weather persistence on sub-seasonal to seasonal timescales: a methodological review

Abstract

Abstract. Persistence is an important concept in meteorology. It refers to surface weather or the atmospheric circulation either remaining in approximately the same state (quasi-stationarity) or repeatedly occupying the same state (recurrence) over some prolonged period of time. Persistence can be found at many different timescales; however, sub-seasonal to seasonal (S2S) timescales are especially relevant in terms of impacts and atmospheric predictability. For these reasons, S2S persistence has been attracting increasing attention from the scientific community. The dynamics responsible for persistence and their potential evolution under climate change are a notable focus of active research. However, one important challenge facing the community is how to define persistence from both a qualitative and quantitative perspective. Despite a general agreement on the concept, many different definitions and perspectives have been proposed over the years, among which it is not always easy to find one's way. The purpose of this review is to present and discuss existing concepts of weather persistence, associated methodologies and physical interpretations. In particular, we call attention to the fact that persistence can be defined as a global or as a local property of a system, with important implications in terms of methods and impacts. We also highlight the importance of timescale and similarity metric selection and illustrate some of the concepts using the example of summertime atmospheric circulation over western Europe.

CMIP6 Models Overestimate the North Atlantic Eddy-Driven Jet Persistence

“…Understanding the dynamics governing persistent weather events is an area of intensive research. It is crucial to evaluate the accuracy of climate models in capturing this persistence for reliable long-term projections, especially regarding high-impact weather phenomena (e.g., Tuel and Martius, 2023). In particular, studies have consistently highlighted the strong association between latitudinal shifts in the jet stream and extreme weather occurrences over Europe (Galfi & Messori, 2023;Mahlstein et al, 2012;Cattiaux et al, 2010;Trigo et al, 2013).…”