Title: Inferring directed climatic interactions with renormalized partial directed coherence and directed partial correlation,
Abstract: Inferring interactions between processes promises deeper insight into
mechanisms underlying network phenomena. Renormalised partial directed
coherence (rPDC) is a frequency-domain representation of the concept of Granger
causality while directed partial correlation (DPC) is an alternative approach
for quantifying Granger causality in the time domain. Both methodologies have
been successfully applied to neurophysiological signals for detecting directed
relationships. This paper introduces their application to climatological time
series. We first discuss the application to ENSO -- Monsoon interaction, and
then apply the methodologies to the more challenging air-sea interaction in the
South Atlantic Convergence Zone (SACZ). While in the first case the results
obtained are fully consistent with present knowledge in climate modeling, in
the second case the results are, as expected, less clear, and to fully
elucidate the SACZ air-sea interaction, further investigations on the
specificity and sensitivity of these methodologies are needed.