Interdecadal Pacific Oscillation reconstructed from trans-Pacific tree rings: 1350–2004 CE

Abstract

The interdecadal Pacific Oscillation (IPO) represents the decadal mode of the El Niño-Southern Oscillation phenomenon. As such the IPO is one of the dominant modes of decadal climate variability on both sides of the Pacific Ocean basin. For this paper we utilized a newly developed tree-ring data network comprised of five multi-centennial Vietnamese cypress ring-width chronologies that range from around 11°N-23°N latitude. We combined these data with an average of tree-ring derived drought indices from the North American Drought Atlas over the south central USA, from a box that spans from 27.5°N-35.0°N, 85.0°-110.0°W and contains 55 gridpoints and more than 100 tree ring site chronologies, these 2 locations exhibit rainfall variations that are strongly, negatively correlated with each other and are representative of the influence of the IPO on terrestrial rainfall. The final reconstruction model, weighted most heavily on the three most southerly of the five Vietnamese cypress records, spans from 1350 to 2004, and explains nearly 57% of the variance in the original IPO data for the 5-month season of October-February. The reconstruction model passes all standard statistical tests using a split calibrationverification scheme. We reveal 15 positive and 15 negative phase shifts of the IPO prior to the period of instrumentation, suggesting that the IPO has been active for at least the past seven centuries with varying degrees of intensity. We compare our reconstruction with two related millennial records: the MacDonald and Case (Geophys Res Lett 32(8):L08703, 2005) tree ring-derived reconstruction of the Pacific Decadal Oscillation, and an ice core-derived reconstruction of the IPO from the Law Dome Ice core in Antarctica by Vance et al. (Geophys Res Lett 33(6):L06712, 2015). While there is good general agreement with the latter record, there are three key periods of the past where the two records are out of phase, and we explore the reasons for this disparity. Direct comparison with the related Tripole Index (TPI) shows weaker correlation, likely owing to the stronger relationship between our tree ring data and the equatorial Pacific region relative to the north and south regions of the Pacific that combine to comprise the TPI calculation.

Increased Variability of Thailand's Chao Phraya River Peak Season Flow and Its Association With ENSO Variability: Evidence From Tree Ring δ18O

“…These results further support the changing ENSO pattern and the increase of ENSO variances as shown in Figure d. We should note that while the spatial correlations (Figure ) also seems to depict the Interdecadal Pacific Oscillation (IPO) pattern (Dong & Dai, ; Meehl et al, ), a comparison of our CPRPF reconstruction with a new IPO reconstruction (Buckley et al, ) reveals that the present CPRPF reconstruction is not significantly correlated with the IPO.…”

Three hundred years of snowpack variability in southwestern British Columbia reconstructed from tree‐rings

“…These events typically coincide with cooler and wetter winters in southwestern BC that tend to promote higher-than-average winter snowpack (Rodenhuis et al, 2009) and higher streamflow discharge totals in western Canada (Whitfield et al, 2010). The reconstructed record is weakly associated with PDO during winter (DJF) and spring (MAM; Table 5), and demonstrates interdecadal spectral variability similar to fluctuations observed in the PDO over the last 300 years (Figure 6a; Mac-Donald & Case, 2006;Buckley et al, 2019). While the PDO is typically associated with multidecadal climate variability in the study region, its influence is less pronounced than that of ENSO (Rodenhuis et al, 2009).…”

On the recent hiatus of tropical cyclones landfalling in NSW, Australia

“…Palaeo-reconstruction is not restricted to just tempest events. Studies by Vance et al (2015) and Buckley et al (2019) demonstrated the potential of extending the instrumental record of large-scale climate indices such as the IPO from proxies to predate 1400. Other studies (Verdon and Franks 2006;Heinrich et al 2009) have used coral and tree-ring records to investigate the relationship of ENSO, IPO and precipitation in Australia.…”