“Beyond Weather Regimes”: Descriptors Monitoring Atmospheric Centers of Action. A case study for Aotearoa New Zealand

Abstract This paper introduces a set of descriptors applied to weather regimes, that allow for detailed monitoring the location and intensity their atmospheric centers action (e.g. troughs ridges) gradients between them, when applicable. Descriptors are designed document effect climate variability change in modulating character daily rather than merely occurrence statistics. As case study, methodology is Aotearoa New Zealand (ANZ), using ERA5 ensemble reanalysis data period 1979-2019. Here, we analyze teleconnections regimes descriptors, large-scale variability. Results show significant modulation by phase Southern Annular Mode, with strong relationship identified latitude ridges. Significant associations El Niño Oscillation also identified. Modes have stronger influence on regimes’ intrinsic features occurrence. demonstrates usefulness such which help understand mid-latitude transient perturbations modes In future research, this methodological framework will be (i) low-frequency changes under change, line southward shift storm tracks, (ii) regional-scale effects ANZ, resulting from interaction its topography.