Empirical Decomposition of Low-Frequency Atmospheric Variability for Climate Dynamics Studies

University Of Washington, Seattle WA

Investigators

Abstract

This project will apply Empirical Mode Decomposition (EMD), a technique for analyzing time series recently developed by Huang et alia (1998), to the 45-year long NCEP reanalysis assimilation in order to study the spatial and temporal structure present in low frequency atmospheric variability. Such variability includes the global Quasi-Biennial Oscillation, a possible El Nino-Southern Oscillation mode, a possible 11-year solar cycle signal, a 22-year cycle (so far unidentified) and a warming trend in the troposphere believed to arise from cooling of the stratosphere. The principal objective of this work is to understand the nature of low frequency variability in the atmosphere, perhaps offering a facility to differentiate between the naturally-occurring and anthropogenically-induced components of this variability. The use of a new method (EMD) will broaden the scope of analysis techniques to probe long-term variability in the atmosphere. The results are expected to benefit the scientific community, and will be disseminated via international scientific journals and major conferences. One female post-doctoral student will receive support and training.