This paper describes a supermodelling framework that combines the effects of the physics parameterization suites from two versions of the Community Atmosphere Model.  The physics suites are combined by nudging each version (model component) to the averaged state on a periodic time interval, as in data assimilation.  

Supermodelling is an interesting idea with interesting potential applications, but I think that the manuscript is not ready for publication for three reasons.  First, the method is not described in enough detail to allow a reader to reproduce the results.  For instance, I couldn’t find a tag of the code listed in the manuscript that would allow me to recreate the figures in the manuscript.  Furthermore, the scripts have hardwired paths (not variables) with little instruction given as to what lines in the scripts need to be modified.  Second, the main application cited is improvement of supermodeled climatologies over the individual components, but only one or two improved fields are shown in the manuscript.  The authors argue that improvement will come with tuning, but one might expect to see improvement even with simple equal weighting of the components.  It might interest readers to see more discussion of which fields are improved and which are degraded, along with any insights that the authors have regarding the reasons that some fields are improved and others are not.  Third, there are many typos in the manuscript, some of which impede understanding of the meaning.  I list just a sample of them below.  My recommendation is that the authors invest more time in the manuscript and deliver a more polished version.

Minor comments:

This part of the caption of Fig. 2 seems to have typos: “SUMO5 (teal); supermodel which uses CAM5-physics (SUMO5); supermodel supermodel which uses CAM6-physics (SUMO6) (purple) at location”

Lines 32–33:  “Additionally, biases which are shared across the individual models in an NIE cannot be corrected due to the linear nature of post-process averaging.”  But does the supermodel succeed in correcting such shared biases?  Can the authors offer any insight into when and why shared biases can be corrected?

Line 80: “the adaptation of the existing nudging toolbox (reference)”.  Typo.  Please include whatever reference you’re referring to here.

Lines 178–180:  “We show results for four experiments: CAM5, CAM6, the supermodel which uses CAM5-physics, but is nudged to the combined state, SUMO5, and the supermodel which uses CAM6-physics, SUMO6.”  Does SUMO6 nudge to the combined state?  If not, how is it different from CAM6?  The sentence ends before the SUMO6 configuration is clearly described.

Line 195: “(Fig. ??, right column)”.  Typo.

Lines 195–196: “Correlations between the SUMO5 and SUMO6 experiments are much higher (3, left column)”  How can a correlation be as high as 3?  Correlations must lie between -1 and 1.

Fig. 4: I’m surprised that CAM5 and CAM6 have such similar distributions of wind speed.  Is there a computational or physical constraint on this distribution?

Line 258: “One reason to develop supermodels lies in their potential to have smaller mean-field biases.”  In the example of surface precipitation shown in Fig. 7, the spatial pattern of errors looks similar (shared) in CAM5 and CAM6.  The hope implied in lines 32–33 was that such error could be reduced below both components by supermodelling.  But Fig. 7 shows that this doesn’t happen for surface precipitation.  Do the authors have an explanation for this failure?  

Line 258: “The work presented her”  Typo.

Lines 278–279: “Positive values (grey) indicate that the SUPERense is outperforming the NIEnse and vise-versa.”  Are positive values grey or green?

Lines 289–290: “This circumvents the in CESM costly initialization stage and introduces effectively PAUSE/RESUME capability (Fig. 1).”  Typos?

Lines 300-301: “To test our implementation we linked the CAM5/CAM6 atmosphere and confirmed that synchronization across various temporal scales and variables Even though the supermodels only exchange limited information . . .”  What did you confirm?

Lines 317–319: “To create all model runs and build your own supermodel, refer to Chapman et al. (2024). This second repository contains the setup for the SuperModel and its constituent models, including source modifications, model build scripts, and namelists for running the described CAM versions.”  Is a tag of the CESM repository listed somewhere so that readers can reproduce the figures in the paper identically?