I would like to thank the reviewer for taking on the m/s for a second time, and for his thoughtful comments.  In response to the detailed comments:

1.  Title

I agree a change of title is required.  A possibility is "ENSO and the temperature of the North Equatorial Counter Current".

2.  Abstract

Yes, I agree.  I will revise the abstract taking into account the points raised.

3.  "The longitude structure of the Hadley Circulation".

I use the term Hadley Circulation here because the NECC is in a region where the atmosphere is responding to the Coriolis term - so it is not part of the walker Circulation.

While I am on the subject : I think the Hadley and Walker Cells to be names which oversimplify what is going on.  Deep convection occurs wherever the conditions are right and the surface air has enough energy to punch through the middle atmosphere to reach 300 hPa and less.  Air then sinks whenever it can radiate to space or can slip sideways and downwards along constant potential density surfaces.

Some of the convection occurs where the Coriolis term is small - some sinking also occurs at such latitudes - but I know of nothing, except convention, to think that convection and sinking near the Equator are connected by anything but luck.

4. Typos

Umm. Perhaps this is AI pretending not to be AI.

5.  Section 21. Heat Forcing

I hope that I understand correctly the point made by the reviewer, but my previous studies using high resolution NEMO and satellite data, indicated that most of the NECC temperature changes in the central and eastern Pacific were due to advection.  See for example the SST figure in my 2017 paper.  The comment shows that I need to say more about the previous study and the role of advection.

6.  Lines 175-190 - Section on Analysis

The earlier section is more about setting up the initial model run and the subsequent runs.  In the present form of the paper section 3.1.1 is self contained, with analysis theory and results.  Moving the analysis theory to an earlier position in the paper would break the connection.  It would also break the connection between the section describing setting up the tests and the description of the initial qualitative results.  My preference is not to change the text.

7.  Line 216.

Yes.

8.  Lines 270-274.  Definition of South-Eastern Pacific

I will be more specific and specific a line roughly between 230E, 15S and 280E, 35S.

9.  Section 5 Addition to the M/S

My problem here is that, at this stage in research, further analysis of the set of runs inevitably results in some changes in emphasis.  The effect of the forcing on the low surface pressure region in the SW Pacific may have been unusually large in the first run studied.  I will say something to this effect in the revised m/s but plan to say more when I write up the results from the full set of runs that has now been completed.

10.  Figure B1.  Direct heating of the NEMO 3.1 region from NECC latitudes

An interesting point that needs further thought.  Figure 8 shows heat being advected from the NECC to the Equator, but this may be an artifact of the forcing due to (a) the increased temperature of the NECC and (b) the tropical instability eddies/waves not having time to spin down.  One of my previous studies found that they were less active during the development of strong El Ninos.

I'll look at the ERA5 SST and velocity fields and see if there is anything worth adding to the revised m/s.

I would like to thank the reviewer for taking on the m/s and for his thoughtful comments.  In response to the detailed comments:

1.  Single Member Study

I agree with the comments on a single member study.  However some of the results were so striking that I thought an initial paper was justified.  I have now completed a set of ensemble runs and am planning how to report the results.

2.  Length of Paper

I am sorry if the paper seems lengthy.  The introduction maybe includes more history than is normal, but I think the supporting arguments may be needed before many people can accept the paper.  There is also the question "Given the evidence, why has it taken 50 years or more for the potential importance of the NECC to be realised?".

The analysis section may also appear long but, because of the contrast with other models of the ENSO process, I thought it was important to go through each stage of the apparent mechanism logically and carefully.

3.  Direct Dynamical responses

Yes I agree and there is evidence of a possible direct advective effect in the figure showing the SST response.  It is for this reason that I have not claimed the surface warming at the Equator to be part of an ENSO response.

I will make this clearer in the revised m/s.

4.  El Nino like changes

I need to be clearer on this issue.  The forcing produced El Nino (ENSO) like changes in the Pacific east of 200E (160W) - i.e. the reduction in the strength of the easterlies and the resulting reduced upwelling and warming at depth.  However the forcing did not produce the classic El Nino signals seen further west, i.e. the region of deep convection that develops around 180E and a region of westerly winds that develops on the Equator west of the deep convection.

There is also a question over the cold pool surface temperatures.  The forcing does increase the Nino 3.4 temperature by a significant amount, but I judged that this was partly due to the advection discussed above, so did not think the result could be used.

Thus for many people the results will not explain the 'El Nino'.

5.  Hadley Circulation

Yes, the increased deep convection above the ITCZ will change the longitudinal structure of the Hadley/Walker circulation.  Such changes are almost certainly responsible for the global impacts of ENSO.  This is quite a claim, so I thought it better to let readers make their own judgment.

I will think about what I can do to be more specific.

6.  Use of 240E, 120 etc.

I realise that the use of 'degrees east' or 'degrees west' can raise the same amount of passion as 'data is' or 'data are'.  I accept that seagoers have a convention of using degrees west in the western hemisphere and I am happy to use that convention for navigation and for the general public.  However when running and analysing models and data, I always have to work in degrees east, whatever the longitude.  So for a professional paper that involves such models and data, I believe that the use of degrees east everywhere is valid.

7.  Figure 1.

I'll add the difference figure.