Indices of Pacific Walker Circulation Strength

The Pacific Walker circulation (PWC) significantly affects the global weather patterns, distribution of mean precipitation, and modulates rate warming. In this study, we review compare 10 different indices measuring strength PWC using data from ERA5 reanalyses for period 1951–2020. We propose a revised velocity potential index, while also discuss two streamfunction indices. show that normalized largely agree on annual-mean PWC, with highest correlations observed between measure closely linked physical processes. tend to disagree most during periods strong El Niño. Therefore, trends in vary depending chosen time frame. While 1981–2010 strengthening, 1951–2020 are mostly neutral, recent (2000–2020) (insignificant) weakening PWC. results hint at multidecadal variability approximately 35 years, which would result continued coming decade.