Effects of ENSO on the major ion record of a Qomolangma (Mount Everest) ice core

Hao Xu,Shugui Hou,Hongxi Pang,Chaomin Wang

doi:10.3189/2016aog71a042

Abstract

AbstractCorrelations between a 1000 year record of the major ions in a 108.83 m ice core from East Rongbuk Glacier (28°01’N, 86°58’E; 6518ma.s.l.) on the northeast slope of Qomolangma (Mount Everest) and the Southern Oscillation Index (SOI) were examined to investigate possible links between the ice-core records of the southern Tibetan Plateau (TP) and El Niño Southern Oscillation (ENSO). The results show that years with the highest crustal ion concentrations and lowest marine ion concentrations corresponded with a low SOI, and vice versa. Cross wavelet and wavelet coherence analysis between major ion time series and the SOI indicated that there were significant sections with high common power between the major ion time series and the SOI, suggesting a correlation between the ion records of the Qomolangma ice core and ENSO. Further investigation indicated that the higher SOI years corresponded with weaker continental air masses and stronger south Asian monsoons over the southern TP, leading to increased marine ions and decreased continental ions transported to the southern TP. The in-phase surface pressure anomalies of the southern TP and Darwin, Australia, link ENSO and ion transport over the southern TP, and thus suggest a link between aerosol transport over the southern TP and ENSO.

Highlights

Ice cores drilled from carefully selected sites are often used to provide palaeoenvironmental records with seasonal, annual, decadal and centennial resolutions (Thompson and others, 2000)
EOF2 accounts for 27.9% of the total variance in the major ion time series, with Cl– and Na+ highly loaded on EOF2
A study of the Dunde ice core showed that the accumulation was positively correlated with the Southern Oscillation Index (SOI) (Davis and others, 2005). These findings suggest that during the warm phase of El Niño Southern Oscillation (ENSO) (El Niño), the pressure above Asia increases; lower temperature, decreased precipitation and increased dust will be prevalent over the Tibetan Plateau (TP), and the south Asian monsoon weakens over the southern TP

Summary

Introduction

Ice cores drilled from carefully selected sites are often used to provide palaeoenvironmental records with seasonal, annual, decadal and centennial resolutions (Thompson and others, 2000). Wang and others (2003) suggested that the d18O time series of the Malan ice core is related to Southern Oscillation indices, possibly driven by the influence of ENSO on the temperature of the TP, via the strength of westerlies and the Indian monsoon.

Results

Conclusion