Empirical Orthogonal Function Spectra of Extreme Temperature Variability Decoded From Tree Rings of the Western Himalayas

Abstract

The ability to distinguish different natural frequency modes from a complex noisy temperature record is essential for a better understanding of the climate response to internal/external forcing. Here we investigate the empirical orthogonal function and spectra of a newly reconstructed tree ring temperature variability record decoded from the western Himalayas for a period spanning 1227 AD to 2000 AD, allowing frequency resolution of interdecadal and interannual oscillatory modes. The spectral analysis of first principal component (PC1) with similar to 61.46% variance reveals the dominance of significant solar cycles notably peaking around 81, 32, 22, and 8-14 years.