Dear Drs. Liu, Tian and co-authors,

Thanks for the revised manuscript and response to the reviewers. The manuscript has much improved but it still needs some minor revision, see the referee's report. Additionally, my comments are listed below.

Please be consistent with all equation numbers. So do not use R1, R2 etc, but start with (1), (2) etc and do so for the whole manuscript.

L28 „because of its reactivity“ This should be something like “high reactivity with other substances”

L35 Shouldn’t one write 2 OH- instead of OH- + OH- ?

L36-38 “Mack and Bolton (1999) had reviewed the possible subsequent reaction like the produced NO and hydroxyl radical (OH) could react to produce HNO2 reversely (R2), and some reaction that consumed NO like R3 to R7” This sentence is not clear. Please modify.

L42 The way this reaction is given is not correct. Actually, these are two reactions. Please correct.

L45 Besides (with capital, start new sentence here)
L45 “could be a potential source” This is double and a style error. Either “could be” or “is a potential source”

L46 R8 is given but this does not contain the reaction that is mentioned.
L48 R8 to R12 (not R11)

L55 summarizes
L119 “with a simple linear regression in artificial seawater samples” This is not clear. Please modify.

L120 “a linear relationship was not found > 30 min for the natural seawater samples” This is not clear, in particular the “>30 min”. Please modify text.

L152 the data were fitted
L226 delete the first which

L260-261 “Zafiriou and McFarland (1981) also demonstrated that artificial seawater comprised with major and minor salts showed complex interactions.” This is very general and thus does not contain any useful info. Please modify.

L299 “The non–existing linear relationship” This is not correct wording. Change to something like: There was no linear relationship found between RNO and dissolved NO2– during our cruise, which is in contrast to the results of …

L324-325 “to be 52% (– 30%)” Is the minus correct, or should it be plus-minus (±)?
L329 delete lower

L419-420 “indicating a further NO loss process in the surface layer. This indicates a further NO loss process in 419 the surface layer of the WTNP.” Double info. Delete one.

L459 … 129, 10597-10601, 2007 (add page numbers)
L493 J. Geophys. Res., 109, C12003, doi:10.1029/2004JC002378. (complete ref)

L509-511 Please provide update (no discussion paper), if available)
L540 H 2 O 2 (change format)

Table 1 Please use date format like 5 October 2009
Table 1 According to your answer to referee #2, this table should contain a column Method. The table shown here does not contain such a column

Best wishes
Mario Hoppema