“…A key purpose of model sensitivity analysis is to inform model calibration or model uncertainty analysis so as to focus either of these analyses on only the model inputs/model structural choices the model outputs are most sensitive to. While the literature on sensitivity analysis for model parameters is rich (Morris, 1991;Sobol', 1993;Demaria et al, 2007;Foglia et al, 2009;Campolongo et al, 2011;Rakovec et al, 2014;Pianosi and Wagener, 2015;Cuntz et al, 2015Cuntz et al, , 2016Razavi and Gupta, 2016a, b;Borgonovo et al, 2017;Haghnegahdar et al, 2017), and there has likewise been a good deal of research into the influence of model input uncertainty (Baroni and Tarantola, 2014;Abily et al, 2016;Schürz et al, 2019), sensitivity to model structural choice has received far less attention (McMillan et al, 2010;Clark et al, 2011). With model structure we refer to various process conceptualizations within a model rather than, for example, model discretization.…”