“…Hakami et al (2005) and Yumimoto et al (2007Yumimoto et al ( , 2008 attempted to apply a four-dimensional variational method (a so-called advanced data assimilation method) to inverse modeling of black carbon (BC) and dust aerosols with ground-based observations and regional models. To date, measurements obtained by various observation platforms, including MODIS (Dai et al, 2014;Huneeus et al, 2012;Wang et al, 2012;Zhang et al, 2008), CALIPSO (Sekiyama et al, 2010;Zhang et al, 2011Zhang et al, , 2014, Himawari 8 (Yumimoto et al, 2016), AERONET (Schutgens et al, 2010a), and surface PM 10 (particulate matter with diameters less than 10 µm) monitoring systems (Tombette et al, 2009;Lee et al, 2013;Jiang et al, 2013), have been used in assimilation studies adopting both variational (Benedetti et al, 2009;Dubovik et al, 2008;Hakami et al, 2007;Henze et al, 2007;Yumimoto and Takemura, 2013) and ensemble-based Schutgens et al, 2010b;Di Tomaso et al, 2017;Yumimoto and Takemura, 2011) methods.…”