Please join us for the next BPE Seminar this upcoming Monday, September 20th at 1 pm for a virtual talk by Dr. Georgy Falster from Washington University in St. Louis titled Multi-method, multi-proxy reconstructions of the Pacific Walker Circulation over the past 400 years.
The Pacific Walker circulation (PWC) affects weather and climate far beyond the tropical Pacific. The PWC is also an important component of the El Niño-Southern Oscillation (ENSO) and its global teleconnections. Understanding drivers of PWC variability—particularly beyond the interannual time scales typically associated with ENSO—is important for understanding impacts of future climate change, but neither the response of the PWC to external forcings nor its natural internal variability are well understood.
We recently demonstrated that there is a strong PWC imprint in the spatio-temporal variability of modern global precipitation δ18O (Falster et al., 2021). That imprint allows us to leverage proxy records for past meteoric water δ18O/δ2H to reconstruct PWC variability back beyond the instrumental era. In the work that I will share in this seminar, we applied several statistical methods to reconstruct the PWC at annual resolution from 1600-2000 CE, using records from the PAGES Iso2k database (Konecky et al. 2020). We use these reconstructions to assess the nature of PWC variability on various time scales, as well as comparing these findings with climate model simulations.