“…The RB method has been widely studied by, for example, Grepl and Patera (2005);Hesthaven et al (2016);Prud'homme et al (2002); Quarteroni et al (2015) for mathematical benchmark examples, and for the first time by Degen et al (2020b) in a geoscientific context. In this study, we make use of the RB method to guide the construction of the surrogate model since it allows, in contrast to other statistical methods including Kriging and response surfaces (Baş and Boyacı, 2007;Bezerra et al, 2008;Frangos et al, 2010;Khuri and Mukhopadhyay, 2010;Miao et al, 2019;Mo et al, 2019;Myers et al, 2016;Navarro et al, 2018), the retrieval of the entire state variable (i.e. temperature).…”