“…This kind of methods includes the single EOF reconstruction method (Carnes et al, 1990(Carnes et al, , 1994, the gravest empirical mode (Meinen & Watts, 2000) and the coupled pattern reconstruction (Buongiorno Nardelli & Santoleri, 2004), and the multivariate EOF reconstruction (mEOF-R) method (Buongiorno Nardelli & Santoleri, 2005;Buongiorno Nardelli et al, 2006;Wang et al, 2012). The mEOF-R method still presents a good performance in recent works to reconstruct the mixed layer depth (Buongiorno Nardelli et al, 2017) and ageostrophic motion (Buongiorno Nardelli et al, 2018) in the Southern Ocean. Occasionally, statistical modes could correspond to physical processes, for instance, the first mEOF of steric height could reflect the first baroclinic mode in Buongiorno Nardelli et al (2006).…”