Attribution and Causality Analyses of Regional Climate Variability

A two-step attribution and causality diagnostic is designed by employing singular spectrum analysis to unfold the attributed climate time series into a trajectory matrix then subjected an empirical orthogonal function identify evolving driving forces, which can finally be related major modes through their independent frequencies wavelet analysis. Application results from arid drought-prone southern Intermountain region of North America are compared with or larger scale forcing diagnosed slow feature using sources water energy flux balance. The following noted: (i) changes between subsequent four 20-year periods 1930 2010 suggest predominantly climate-induced Pacific Decadal Oscillation Atlantic Multidecadal Oscillation. (ii) Land cover influences on changing land considerably smaller magnitude (in terms area percentage cover) whose evolution well documented forestation documents. (iii) drivers forcings within last 20 years identified as quasi-biennial oscillation El Niño–Southern both inter-annual diagnostics monthly scale-based