Reviewer's Comments:

This is a review of the paper "On the existence of 
shear-current effect in magnetized burgulence" about 
dynamo effects in shear flows. The paper studies possible 
candidate dynamo mechanisms in driven shear flows using 
various "test-field methods" to compute the dynamo transport 
coefficients. They study full MHD and a simplified MHD, which 
removes the pressure force from the momentum equation to 
simplify the calculation of the transport coefficients. 
The main result is that in most cases the dynamo is driven 
by fluctuations in the transport coefficients, rather than 
a coherent shear-current effect. I have a few important 
concerns that should be addressed before publication.

- It is nice to be able to measure transport coefficients 
for dynamos directly, which make the TFM quite powerful. 
However in this paper it has come at the price of changing 
the equations. It is important for the reader/community 
to be able to clearly assess what this price is. With 
this in mind, it is important to provide a more detailed 
comparison with standard MHD (FMHD in the paper). First, 
although there is a lot of discussion about the structure 
of the butterfly diagram (and later transport coefficient 
fluctuations) for the FK cases, this is not shown. It is 
important for a reader to be able to see the difference, 
since a fair amount of weight is placed on this in comparing 
to magnetically forced ones. Second, although it is difficult 
to measure transport coefficients, it is important to see 
the difference with some magnetically forced FMHD runs, 
again in the butterfly diagrams (also the growth rates). 
This way we can assess the impact of SMHD and whether this 
is likely to significantly change the main conclusions of 
the paper (e.g., does the field wandering change), as well 
as better understanding the observed similarities/differences 
to Squire & Bhattacharjee 2015 and Brandenburg et al. 2008. 
It would be nice to see both standard and decimated forcing 
here (given uncertainties around the latter as well).

- A similar point applies to the zeroing out of the mean U. 
While I appreciate that the authors do not want to extensively 
explore this, a basic comparison of a case with and without 
zeroing U is important for readers to understand if this 
also affects B (and thus the main conclusions) significantly.

- The NLTFM is the important novelty of this work but 
I found its description quite confusing. A few points 
that would help:
- Mention at the start of 2.3 the basic purpose of the NLTFM 
and explain that it is tested in more detail in appendix. Those 
(like myself) who are not familiar with RB10 will not understand 
just how complicated the NLTFM has to be, and it will help to give them a warning.

- Explain the removal of U earlier in the discussion. It is finally 
introduced in 2.8, but it's been mentioned twice previously without 
forward reference (e.g., below equation (8) and in 2.5). This is quite 
important (see previous point) so needs to be very clear. Currently it 
comes across as being related to the NLTFM, not the equations themselves.

- I think there is maybe a typo in (1)-(2), (6) and (7)-(8), since 
F_K is magnetic and F_M is kinetic forcing. It is also a bit confusing 
to define both lower and upper case F, when F=f.

- Section 2.3, the discussion following "Normally taken to be a Reynolds 
average, in situations with shear..." is confusing and I didn't understand 
what it was saying. Please reword and make any definitions clearer.

- The sentence below (16) "Here we chose to use in Eqs. (14)-(16) and 
the corresponding versions of the fluctuating terms the first one," I 
believe this means that all of the left hand sides are being used. 
Following RB10 and the appendix, it would be much clearer to write 
(14)-(16) by introducing the ju, jb... notation, and explaining 
'in a bit more detail the different choices.

- Shouldn't section 2.7 go into 2.3 on the TFM? It's an 
important part of the method.

- Lu didn't seem to be used. The dimensionless number 
Brms/urms might be easier to understand.

- It would be helpful to define \lambda in 2.6 so 
that readers can easily find the important symbols.

- Given that they're key for the entire paper, it would 
be nice to introduce eta and alpha more than currently done in (11)-(12). 
A separate section explaining intuitively what each term 
(alpha_xx, eta_yx...) does would be helpful.

- In figures 1a and 1b, SMK1ad has different colors, which is 
confusing when one first looks at the figure.

- Just before 3.3, the authors discuss the results of Shi et al. 
(2016), and why they might be different, mentioning rotation. Much 
more important is probably that Shi et al. (2016)'s simulations were 
undriven (the MRI) which means the saturation amplitude is set 
self-consistently, perhaps in conjunction with other processes. 

- Figure 6 is interesting and useful at explaining the observed 
dynamo growth rates (with most cases well explained by the 0-D model). 
But it is not properly explained how it is computed. Please add more 
discussion of this, at least the equations solved and how they're used 
to construct the contour plots. 

- Also, f6's labels are too small to read clearly. 

- Which run in figure 8? And are the two snapshots just different 
times (if so when)?