A Partial Eruption of a Sigmoid Filament in the Small Dipole Active Region 12734
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsReview Report: universe-2721755
The manuscript is based on the observational data and overall very interesting in its outcomes/results, however I
have a few issues for the authors which they should take care of in the Revision.
1. What is the proper physical (or even chemical) cause behind `disobeying the hemispherical helicity rule’?
2. Whether the observed `local’ effect is responsible, in any reasonable way, for the `global effect’ of coronal
ejection as well as other side effects?
3. Is there any relationship between the 11 years Solar cycles and the presented phenomenon in the
manuscript?
4. I’m afraid of the quality of the manuscript which mainly consist of a few observational data plots without
much mathematical as well as physical presentation.
I think the updated manuscript based on the abovementioned issues may be acceptable for publication.
Author Response
Dear Editors and Reviewer:
Firstly, we thank you very much for your timely response, critical comments, and helpful suggestions on our manuscript entitled "A Small flare erupted in NOAA AR 12734 disobeying the hemispherical helicity rule" (universe-2721755). The comments are valuable and very helpful. We have read through the comments carefully and have made corresponding corrections. Responses to your comments are marked in blue and presented below.
Sincerely yours
Jihong liu.
Our responses to your Comments of universe-2721755 are listed in the following:
Comments of Reviewer:
The manuscript is based on the observational data and overall very interesting in its outcomes/results, however I have a few issues for the authors which they should take care of in the Revision.
- What is the proper physical (or even chemical) cause behind `disobeying the hemispherical helicity rule’?
Answer: AR 12734 is located near 8.9° north latitude during its solar disk passage at the end of Solar Cycle 24, with same signs of twist and writhe (both positive). Such AR tends to disobey the hemispheric preference. Zhang et al. (2010) studied the AR vector magnetograms for more than 20 years at observatories in Mees, Huairou and Mitaka, and found areas of the ’ wrong’ sign at the ends of the butterfly wings as well as at their very beginnings. Liu et al. (2014b) studied 82 bi-pole ARs and found that bipolar ARs having the same signs of twist and writhe do not have a strong hemispheric preference, which may suggest that the twist generated by the dynamo process has no hemispheric preference. See the sentences marked in blue in the second paragraph in section 3.2.2.
- Whether the observed `local’ effect is responsible, in any reasonable way, for the `global effect’ of coronal ejection as well as other side effects?
Answer: Yes. The magnetic reconnection triggers the partial eruption of the filament of the ARs associated with the C1.3 flare, then pushes the overlying magnetic field outward, results in the global EUV waves and CME. We add a description to mention the point, see the sentences marked in blue in the last paragraph of the text.
- Is there any relationship between the 11 years Solar cycles and the presented phenomenon in the manuscript?
Answer: ARs tend to disobey the HH rule at the beginning of the new solar cycle or the end of the old one. This is due to the phase relation between the toroidal and poloidal fields generated by Babcock–Leighton type dynamo models. See the sentences marked in blue in the last paragraph in section 3.2.2.
- I’m afraid of the quality of the manuscript which mainly consist of a few observational data plots without much mathematical as well as physical presentation.
Answer: We did a lot of calculations but did not provide them. We have added explanations for the calculation formula and specific parameters. See the sentences marked in purple in the second paragraph of section 2. (Another reviewer also pointed out the equation items should be explained in the text.)
I think the updated manuscript based on the above-mentioned issues may be acceptable for publication.
Answer: Thanks again.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript is entitled “A Small flare erupted in NOAA AR 12734 disobeying the hemispherical helicity rule”, but focuses on the evolution of a sigmoid structure and the magnetic field evolution of the AR. The results are not clearly presented, and the conclusions are not supported well. In addition, the English grammar and style need substantial improvements. Hence, I suggest that a major revision for the manuscript before it can be considered suitable for acceptance.
Major issues:
1. The title should be corrected as “A partial eruption of sigmoid filament in AR 12734”.
2. The authors did not capture the key structures of the eruption process, and were misled by some details of the eruptions. It resulted in the disorder of the results of the eruption. For example, it is likely that L3 is another branch of L1, and L2 just represents the large-scale overlying confinement field.
The authors are recommended to focus on the eruption of a sigmoid filament lying along the PIL of a dipole AR, and to discuss the role of peculiar AR on the mechanism of the eruption and following confinement.
3. Please add a figure of the evolution of the magnetic field to show clearly the emergence and cancellation that is important for the eruption onset.
4. Please delete the section of waves that deviated from the subject theme of the manuscript.
Comments on the Quality of English Language
The English grammar and style need substantial improvements. Please check carefully the full text of the manuscript.
1. The English grammar in some sentences of ‘Chinese-English’. For example, Line 2 in Abstract, ‘NOAA 12734 … which erupted a C1.3-class flare’ .
2. The usage of abbreviations. For example, Line 63 and Line 81, Page 2, ‘magnetic flux rope (MFR)’à ‘MFR’, ‘active region (AR)’à’AR’; Line 165, Page 8, ‘(FPIL)’à’PIL’.
3. The usage of ‘a’ and ‘an’. For example, Line 275, Page 12, ‘ a EUV’à’an EUV.’
4. The usage of reference citing. For example, Line 37, 39, 42, 45, 72, Page 2, ‘Liu et al 2021’à’Liu et al. (2021)’
Author Response
Dear Editors and Reviewer:
Firstly, we thank you very much for your timely response, critical comments, and helpful suggestions on our manuscript entitled "A Small flare erupted in NOAA AR 12734 disobeying the hemispherical helicity rule" (universe-2721755). The comments are valuable and very helpful. We have read through the comments carefully and have made corresponding corrections. Responses to your comments are marked in red and presented below.
Sincerely yours
Jihong liu.
Our responses to your Comments of universe-2721755 are listed in the following:
Comments of Reviewer:
The manuscript is entitled “A Small flare erupted in NOAA AR 12734 disobeying the hemispherical helicity rule”, but focuses on the evolution of a sigmoid structure and the magnetic field evolution of the AR. The results are not clearly presented, and the conclusions are not supported well. In addition, the English grammar and style need substantial improvements. Hence, I suggest that a major revision for the manuscript before it can be considered suitable for acceptance.
Major issues:
- The title should be corrected as “A partial eruption of sigmoid filament in AR 12734”.
Answer: The title has been corrected as “A Partial Eruption of Sigmoid Filament in a Small Dipole Active Region 12734”.
- The authors did not capture the key structures of the eruption process, and were misled by some details of the eruptions. It resulted in the disorder of the results of the eruption. For example, it is likely that L3 is another branch of L1, and L2 just represents the large-scale overlying confinement field. The authors are recommended to focus on the eruption of a sigmoid filament lying along the PIL of a dipole AR, and to discuss the role of peculiar AR on the mechanism of the eruption and following confinement.
Answer: This is a very important and useful recommend. We have rewritten the relevant contents. See the sentences marked in red in line 48 and 82 on Page 2, line 142 on Page 5, line 291, 299 and 318 on Page 11.
- Please add a figure of the evolution of the magnetic field to show clearly the emergence and cancellation that is important for the eruption onset.
Answer: The figure of the evolution of the magnetic field has been added, as shown in Figure 4 in the text (The original Figure 4 has been changed to Figure 5, and so on). See the figure on page 8.
- Please delete the section of waves that deviated from the subject theme of the manuscript.
Answer: We have deleted the section of waves, such as “EUV” and “QFP” etc. in the abstract and in the text. Just briefly mention them in the introduction of the AR.
Comments on the Quality of English Language
The English grammar and style need substantial improvements. Please check carefully the full text of the manuscript.
- The English grammar in some sentences of ‘Chinese-English’. For example, Line 2 in Abstract, ‘NOAA 12734 … which erupted a C1.3-class flare’ .
Answer: The word ‘which erupted’ has been replaced by ‘associated with’ and we have rewritten the sentence as ” NOAA 12734 … which associated with a partial eruption of sigmoid filament, a C1.3-class flare and large scale disturbances:…”. See the sentence marked in red in the second line of the abstract.
- The usage of abbreviations. For example, Line 63 and Line 81, Page 2, ‘magnetic flux rope (MFR)’à ‘MFR’, ‘active region (AR)’à’AR’; Line 165, Page 8, ‘(FPIL)’à’PIL’.
Answer: We have used abbreviations where needed. See the words marked in red in line 64 and 83 of page 2, line 186 of page 7, line 305 of page 11.
- The usage of ‘a’ and ‘an’. For example, Line 275, Page 12, ‘ a EUV’à’an EUV.’
Answer: We have checked the usage of “a” and “an” and corrected them.
- The usage of reference citing. For example, Line 37, 39, 42, 45, 72, Page 2, ‘Liu et al 2021’à’Liu et al. (2021)’
Answer: We have checked the usage of reference citing and corrected them with “()”. See the years marked in red in line 37, 39, 42, 45 and 74.
Reviewer 3 Report
Comments and Suggestions for AuthorsReferee report on universe-2721755
The manuscript can not be recommended for publication in the present form. I will list my comments as they appear in the manuscript.
Preparation is utterly unsatisfactory. Authors did not take time to make sure that all style problems are fixed. Even affiliations are badly written: is it just China or People’s Republic of China? Some co-authors list emails, some don’t. Misspelling (line 69), bad grammar, improper citation (numbers or names? line 69), multiple definitions of abbreviations (MFR, FPIL), absence of definitions (QPD, CME, HMI), lack of proper referencing, bad formatting (empty page), repetitions, low image quality all of these produce a very bad impression about the quality of the manuscript as well as the research.
Line 26: references needed to clearly define the small scale eruptions. How do we distinguish between small-scale and the "normal" eruptions?
Lines 60-61: “kink instability occurs when q < 1. However, the real threshold for instability lies at 2.5*pi by analytical and numerical studies ([23]).” do authors mean when q<2.5*pi? it is a very big difference between q<1 and q<2.5*pi. What is the 2.5*pi?
Line 84: are flares causing filament eruptions? What caused the flares then?
Line 108: the EUV wave is a horizontal, surface structure. A CME is a 3d structure with a large vertical extent. How is the travel distance of the EUV wave related to the height of the CME?
Please, describe and explain all variables in all equations.
My understanding is that DAVE4VM produces flow maps. How was the helicity transport rate calculated? Is the helicity transport rate the same as the commonly used term helicity injection rate? What method has been used? How do authors calculate A_p? What is the A_p?
Fig 1. Why do authors show data taken 3 hours before the flare onset and not immediately before the flare?
Generally speaking, Section 3.1 full of speculations and baseless statements. Considering the very bad image quality in Fig 2, it is impossible to reliably identify which loop connects to which sunspot. The better resolution data available online tells a different story.
Lines 137-140: I do not see any evidence of loops L1 and L3 crossing, as a matter of fact, I can not really identify L3 in Fig 2. Authors also mention some “funnel-shaped field lines”, which they do not indicate and I can not find.
So, the Lf1 begins to erupt after the flare has started and first signs of post eruption arcade (PEA) are already evident in the data. What is then the role of Lf1 and Lf2 in the flare initiation process? According to the authors Lf1 failed and Lf2 erupted. Are those two separate loops? What is their role in producing the flare and a CME? Authors also do not present a coherent picture of the eruption. For example, they fully ignore the origin and evolution of flare ribbons and the PEA. “Se” is the PEA, please use the commonly accepted terminology
Line 145: it is not clear, a loop either erupts or it does not. Was it a partial eruption as in filament or something else?
Line 150-151: it looks like Lf2 is at the periphery of the AR and represents horizontal loops that are likely to be a part of the overlying fields. In any case, the presence of strong overlying fields is a pure speculation since no decay index was calculated for that location.
Line 154: a coronal hole formed in an AR? I don’t see any CH. Authors probably talk about a coronal dimming, which is not the same as a coronal hole.
Fig 3, top panel: the arrows are too small and are mostly unreadable.
Line 164: how is FPIL defined? What is it?
Line 166: I honestly don’t see an inverted delta structure. A delta structure is defined as two umbra of opposite polarities that are very close together and surrounded by one penumbra. This AR has only one sunspot.
Line 184: only less than 25% of the arrows in the SE part of the sunspot show slightly curved trajectories indicating that there might be a CCW rotation of the sunspot. Other areas of the sunspot, as well as other magnetic structures do not show any consistent and well pronounced vortices. As far as I can tell from the top panel in Fig 3, the horizontal magnetic fields do not show such rotation as well. Also, the direction of the EUV loops at that location and the direction of the flows differ and show opposite sense of twist. While I agree that it is an anti-hale AR, the magnetic field data does not show any convincing evidence for it.
Fig 4. The writhe abraptly changes its sign at t=20h. Authors ignore that fact. Why does it happen? I would understand a gradual change, but what is shown in Fig 4 indicates some problems with calculations. I do not see much sense of commenting on this figure until the plot is properly explained.
Line 236: the authors have made multiple statements without providing any references. For example, How do authors arrive at the conclusion on line 236-237? Is it common knowledge or is it an assumption?
Proper calculations of the decay index are done using potential field extrapolation. The threshold was determined based on potential field model. Authors did not indicate what kind of extrapolations they used, but my guess is that it was NLFFF, which is unacceptable.
I will not comment on the conclusions until the manuscript is properly modified.
Comments on the Quality of English LanguageWhile the English is good enough and allows to fully understand what authors intended to say, it must be improved. In particular, authors persistently use the present terms while describing the event. Also, there are some minor grammar problems, which must be corrected.
Author Response
Dear Editors and Reviewer:
Firstly, we thank you very much for your timely response, critical comments, and helpful suggestions on our manuscript entitled "A Small flare erupted in NOAA AR 12734 disobeying the hemispherical helicity rule" (universe-2721755). The comments are valuable and very helpful. We have read through the comments carefully and have made corresponding corrections. Responses to your comments are marked in green (some in other colors when other reviewer ) and presented below.
Sincerely yours
Jihong liu.
Our responses to your Comments of universe-2721755 are listed in the following:
Comments of Reviewer:
The manuscript can not be recommended for publication in the present form. I will list my comments as they appear in the manuscript.
Preparation is utterly unsatisfactory. Authors did not take time to make sure that all style problems are fixed. Even affiliations are badly written: is it just China or People’s Republic of China? Some co-authors list emails, some don’t. Misspelling (line 69), bad grammar, improper citation (numbers or names? line 69), multiple definitions of abbreviations (MFR, FPIL), absence of definitions (QPD, CME, HMI), lack of proper referencing, bad formatting (empty page), repetitions, low image quality all of these produce a very bad impression about the quality of the manuscript as well as the research.
Answer: We are very sorry for making you feel bad, and we’ve tried our best to improve the manuscript according to your comment. Particularly, I reinstalled LaTeX and the images of the compiled manuscript looks clearer.
The affiliations and emails have been rewritten.
The name has been rewritten as Régnier. See the word in green in line 69.
Unnecessary definitions of abbreviations (MFR, FPIL) have been removed.
See the words marked in red in line 64 and 83 of page 2, line 186 of page 7, line 305 of page 11.
Absence of definitions have been added. See the word marked in red/green
in line 92,93/109.
Line 26: references needed to clearly define the small scale eruptions. How do we distinguish between small-scale and the "normal" eruptions?
Answer: We have searched on ADS and found that the concept of “small-scale eruptions” is not applicable here. “The small-scale eruptions are omnipresent features in the quiet Sun, estimated with as many as 1400 events per day over the whole Sun” (The Astrophysical Journal Letters, 952:L29 (8pp), 2023 August 1, https://doi.org/10.3847/2041-8213/ace437). So we replace this phrase by “the rather weak ARs with very modest flare”, see the words marked in green in line 24.
Lines 60-61: “kink instability occurs when q < 1. However, the real threshold for instability lies at 2.5*pi by analytical and numerical studies ([23]).” do authors mean when q<2.5*pi? it is a very big difference between q<1 and q<2.5*pi. What is the 2.5*pi?
Answer: The safe factor is related to the twist angle through the equation . When q<1, we can get . The minimum twist is reported as 2.5*pi by analytical and numerical studies. See the words marked in green in line 62.
Line 84: are flares causing filament eruptions? What caused the flares then?
Answer: The magnetic reconnection of highly twisted helical flux ropes triggers the filament eruptions and the flare. See the words marked in red in line 82-83, and the sentences marked in blue in the last paragraph of the manuscript.
Line 108: the EUV wave is a horizontal, surface structure. A CME is a 3d structure with a large vertical extent. How is the travel distance of the EUV wave related to the height of the CME?
Answer: They are only relevant in terms of time, and it’s just an estimate. Another reviewer recommends deleting the section of waves. So, we delete the statement.
Please, describe and explain all variables in all equations.
Answer: We’ve described the variables in the equations. Please see the sentences marked in purple in the second paragraph on page3, and the sentences marked in green in the last paragraph of section 2 on Page 4.
My understanding is that DAVE4VM produces flow maps. How was the helicity transport rate calculated? Is the helicity transport rate the same as the commonly used term helicity injection rate? What method has been used? How do authors calculate A_p? What is the A_p?
Answer: Yes, the vector velocity field can be produced by the DAVE4VM method. The helicity flux can be calculated by using Eq. 1 and the derived velocity perpendicular to magnetic field lines. where Ap is the vector potential of the potential field Bp. A_p can be calculated conveniently based on observed light-of-sight magnetic field. Please see the sentence marked in green in line 113-114 on Page 3.
Fig 1. Why do authors show data taken 3 hours before the flare onset and not immediately before the flare?
Answer: We firstly try to show more images and avoid duplication. On the other hand, the image of 304 has the best sigmoid shape at 00:00UT, and the filament has a noticeable increase in brightness immediately before the flare. Anyway, we show images by data taken right before the flare in Fig 1, with the 171 image by using data 5 minutes prior the other three to avoid duplication. See Fig. 1 and the caption marked in green
Generally speaking, Section 3.1 full of speculations and baseless statements. Considering the very bad image quality in Fig 2, it is impossible to reliably identify which loop connects to which sunspot. The better resolution data available online tells a different story.
Answer: After reinstalling the LaTeX, the images of the compiled manuscript looks a little better now. Fig. 1(d) is relatively larger than Fig. 2(a), which can provide a clearer view of the direction of the loop.
Combining animation and magnetic field extrapolation, we propose that both L1 and L3 connect the sunspots P1 and N1, and they twisted together. In other words, L3 is another branch of L1. L2 just represents the large-scale overlying confinement field which connect the sunspot P3 and N1 (See the figure right). See the sentences marked in red in the second paragraph of section 3.2.3 on page 11. A small 171 image is placed on the bottom left corner in Fig.1 panel (d), with the red/blue cross symbols mark the loop L1/L3. See Fig.1 and the caption marked in green.
Lines 137-140: I do not see any evidence of loops L1 and L3 crossing, as a matter of fact, I can not really identify L3 in Fig 2. Authors also mention some “funnel-shaped field lines”, which they do not indicate and I can not find.
Answer: Answer: To recognize the loops in Fig.2, please refer to the cross symbols
in Fig.1 (d) .
The funnel-shaped field lines can reference the Fig.1(a) of Miao et al. (2021):’The white dotted lines indicate the borders of coronal funnel FL1 and FL2’ (https://doi.org/10.3847/2041-8213/abdfce). See the sentences marked in green in line 153 on page 5.
So, the Lf1 begins to erupt after the flare has started and first signs of post eruption arcade (PEA) are already evident in the data. What is then the role of Lf1 and Lf2 in the flare initiation process? According to the authors Lf1 failed and Lf2 erupted. Are those two separate loops? What is their role in producing the flare and a CME? Authors also do not present a coherent picture of the eruption. For example, they fully ignore the origin and evolution of flare ribbons and the PEA. “Se” is the PEA, please use the commonly accepted terminology
Answer: Both Lf1 and Lf2 failed to erupt. They represent the parts falling back. The C1.3 flare has two X-ray radiation peak, at the fist/second peak time, Lf1/Lf2 appeared. the sustained emergence and cancellation make the magnetic reconnection between L1 and L2 on the X point happens, and the reconnection triggers the partial eruption of the filament of the ARs associated with the C1.3 flare, accompanied by the open and relax of the nearby magnetic line-of-force and clockwise rotation of the main spot. The raised MFR pushes the large-scale overlying confinement field outward, simultaneously transporting helicity and energy to the upper atmosphere, and subsequently resulted in the global EUV waves and CME.
See the sentences marked in red in the abstract and in the second paragraph
of section 3.2.3 on Page 11, and see the sentence marked in blue in the last
paragraph of the manuscript.
The “Se” is refer to the filament channel, not the “PEA”. See the figure right. If I
mark it by a curve line, the real dark filament will be hidden. See the word in the caption of Fig.2 and the last sentences marked in green in line 179-183 on Page 5.
Line 145: it is not clear, a loop either erupts or it does not. Was it a partial eruption as in filament or something else?
Answer: Yes, it is a partial eruption. Also see the sentence marked in blue in the last paragraph of the manuscript, and so on.
Line 150-151: it looks like Lf2 is at the periphery of the AR and represents horizontal loops that are likely to be a part of the overlying fields. In any case, the presence of strong overlying fields is a pure speculation since no decay index was calculated for that location.
Answer: The decay index n is about 1.74 (this value is the recalculated result according to your suggestion, please refer to our answer to the last comment) at the height of 27.2 Mm at the ‘C’ point " in Figure 6. Due to observation limitations, the decay index of the large-scale overlying magnetic field cannot be accurately calculated, but one can still speculate the presence of strong overlying fields. See line 166-170 on page 5, and line 313-320 on page 11.
Line 154: a coronal hole formed in an AR? I don’t see any CH. Authors probably talk about a coronal dimming, which is not the same as a coronal hole.
Answer: All the “coronal hole” has been replaced by “coronal dimming” , see the words marked in green in line 172,175,176 and 349.
Fig 3, top panel: the arrows are too small and are mostly unreadable.
Answer: We have redrawn the image, the arrows are larger than before.
Line 164: how is FPIL defined? What is it?
Answer: Flaring Polarity Inversion Line (FPIL). It refers to the intersection of the PIL and the flare region at the peak time of AIA 1600 Å. See the word marked in green in line 307.
Line 166: I honestly don’t see an inverted delta structure. A delta structure is defined as two umbra of opposite polarities that are very close together and surrounded by one penumbra. This AR has only one sunspot.
Answer: The “inverted δ structure” has been replaced by “the Ω structure”. See the word marked in green in line 188 and 346.
Line 184: only less than 25% of the arrows in the SE part of the sunspot show slightly curved trajectories indicating that there might be a CCW rotation of the sunspot. Other areas of the sunspot, as well as other magnetic structures do not show any consistent and well pronounced vortices. As far as I can tell from the top panel in Fig 3, the horizontal magnetic fields do not show such rotation as well. Also, the direction of the EUV loops at that location and the direction of the flows differ and show opposite sense of twist. While I agree that it is an anti-hale AR, the magnetic field data does not show any convincing evidence for it.
Answer: Hale’s law states that, at any moment, sunspot polarity pairs have opposite sign orientation between the Northern and Southern Hemispheres.
Joy’s law describes the latitude dependence of the tilt of bipolar sunspot regions: the leading spots are closer to the equator than the following spots and this tilt angle increases with increasing latitude.
The AR 12734 is following the Hale’s law and Joy’s law. However, it disobeys the HH rule, i.e., it has positive helicity, and it is located in the northern hemisphere. As can be deduced from the character α_av and the helicity accumulation ΔH. Returning to sunspot rotation, clockwise rotation movement may be caused by counterclockwise spiral. See the sentences marked in purple in the last paragraph of section 3.1 on page 8.
Fig 4. The writhe abruptly changes its sign at t=20h. Authors ignore that fact. Why does it happen? I would understand a gradual change, but what is shown in Fig 4 indicates some problems with calculations. I do not see much sense of commenting on this figure until the plot is properly explained.
Answer: This abrupt change is due to the definition of writhe. The tilt angles are set to be positive when measured in the counterclockwise direction and are in the interval from -90° to 90°. The benefits of such definition will be highlighted in statistical research. If we add 180° to the data before t=20h, then all the writhe should be positive and the abrupt changes will vanish. See the words marked in green in line 125-127 on Page 4, and line 225-226 on Page 8 and 9.
Line 236: the authors have made multiple statements without providing any references. For example, How do authors arrive at the conclusion on line 236-237? Is it common knowledge or is it an assumption?
Answer: We’ve added references of Leka et al. (1996), see line 277.
Proper calculations of the decay index are done using potential field extrapolation. The threshold was determined based on potential field model. Authors did not indicate what kind of extrapolations they used, but my guess is that it was NLFFF, which is unacceptable.
Answer: Answer: We have made a mistake here, now we use the potential field
extrapolation to replace the NLFFF extrapolation to calculate the decay index. The resulted decay index number became larger: it is about 1.74 at the height of 27.2 Mm, while not 0.52, thank you very much indeed. See the words marked in green in line 305,312,340,352.
I will not comment on the conclusions until the manuscript is properly modified.
Answer: Thanks again, we’ll try our best to improve the manuscript.
Comments on the Quality of English Language
While the English is good enough and allows to fully understand what authors intended to say, it must be improved. In particular, authors persistently use the present terms while describing the event. Also, there are some minor grammar problems, which must be corrected.
Author Response File: 
Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsComments for author File: Comments.pdf
I tried to correct errors, but I definitely missed some. Please pay a special attention to prepositions and plurals.
Author Response
Dear Editors and Reviewer:
Firstly, we thank you very much for your timely response, critical comments, and helpful suggestions on our manuscript entitled "A Small flare erupted in NOAA AR 12734 disobeying the hemispherical helicity rule" (universe-2721755). The comments are valuable and very helpful. We have read through the comments carefully and have made corresponding corrections. Responses to your comments are marked in purple and presented below.
Sincerely yours
Jihong liu.
Our responses to your Comments of universe-2721755 are listed in the following:
Comments of Reviewer:
The paper is devoted to a thorough analysis of a rather weak active region with a very modest flare. This unusual data selection makes the work exclusive and useful because the majority of flare investigations consider strong flare events. This research demonstrates a conceptual idea that flares on the Sun are self-similar phenomena following the common laws. To this end, I suggest to publish the article. I did not find any major flaw, and my below listed comments are aimed to slightly improve the manuscript.
Answer: Thank you very much for your affirmation. Your encouragement has given me confidence to continue working hard on solar physics research. We’ve used your sentence in the text, see the sentences marked in purple in the last paragraph of the manuscript.
Comments:
1.Introduction, line 34: “… which including…” → “which includes”.
Answer: The word ‘including’ has been replaced by ‘includes’ , see the words marked in purple in line 34.
- Line 45: “ a helical Kink-unstable” → “a helical kink-unstable”.
Answer: The first letter of this word has been changed from uppercase to lowercase. See the word marked in purple in line 45.
- Line 56: “in a contained flux system” -> maybe, “in a confined flux system”?
Answer: Yes, in a confined flux system. See the word marked in purple in line 58.
- Line 75: “It has been recognized statistically that…” → “It has been shown (revealed, found) statistically that”.
Answer: The word ‘recognized’ has been replaced by ‘revealed’ , see the words marked in purple in line 77.
- Line 77: “ which is called hemispherical helicity rule (HH rule) [27,28]”. The cited publications appeared much more later then the HH rule was found. These references can add the list but cannot be manifested as a primary origin. The three essential publications where the HH rule comes from are: \bibitem[Pevtsov et al.(1995)]{1995ApJ...440L.109P} Pevtsov, A.~A., Canfield, R.~C., Metcalf, T.~R.\ 1995.\ Latitudinal Variation of Helicity of Photospheric Magnetic Fields.\ The Astrophysical Journal 440, L109. doi:10.1086/187773 \bibitem[Abramenko et al.(1996)]{1996SoPh..168...75A} Abramenko, V.~I., Wang, T., Yurchishin, V.~B.\ 1996.\ Analysis of Electric Current Helicity in Active Regions on the Basis of Vector Magnetograms.\ Solar Physics 168, 75–89. doi:10.1007/BF00145826 \bibitem[Bao and Zhang(1998)]{1998ApJ...496L..43B} Bao, S., Zhang, H.\ 1998.\ Patterns of Current Helicity for the Twenty-second Solar Cycle.\ The Astrophysical Journal 496, L43–L46. doi:10.1086/311232
After these three references, you may add the 27,28 papers.
Answer: Yes. The mentioned three papers have been added to the citation list. See the references marked 28,29,30.
- Line 85: “to investigate the dynamics evolution” → either “to investigate the dynamics and evolution”, or “to investigate evolution”.
Answer: The word ‘dynamics’ has been replaced by ‘dynamic’ , see the words marked in purple in line 84.
- Page 3, Eq. 1. The equation is not used and the items are not explained in the text. I presume that this equation was placed here to decorate the manuscript only. The rate dH/dt was delivered by DAVE? Please specify this point. And, more important, please specify how you get the helicity accumulation Delta H, especially, the limits of integration in time and space. My concern is the following. As I see from Fig 2, the area where the field exceeds 320 G is an ensemble of too small patches. Does DAVE accumulates helicity only inside these patches? And the Delta H value comes from such a procedure? Then a question arises: how the result in Fig.4 (red) will change if another threshold will be adopted? In general, what is the accuracy of the helicity parameters evaluations basing on such a small fragments of the AR?
Answer: Yes, the rate dH/dt was delivered by DAVE. We and a few sentences to specify this point and related calculation issues. The helicity was computed by integrating over time the helicity flux during the entire emergence of the AR (AR 12734 is newly emerging flux region and the SDO magnetic observation covering the entire evolutionary period of the AR). Only pixels with a field strength greater than 10 G are included for the computation of (dH/dt). If adopting a higher threshold (e.g., 100G), the result in Fig.5 (red) will became smaller correspondingly (the maximum value of ΔH is about 22*10^40MX^2, i.e., 14% lower), with very similar evolution trend of the curve. 300G is the threshold only for the computation of alpha_{av}. See the sentences marked in purple in the second paragraph of section 2 on page3.
- Line 110, further: “by dividing the tilt angle with the separation” → “by dividing the tilt angle by the separation”
Answer: The word ‘with’ has been replaced by ‘by’ , see the word marked in purple in line 122 on page 3.
- Fig 2, caption. Please add the date of observations. R1 and R2 should be marked in the (d) and should be mentioned in the caption, not only in the text.
Answer: The date of observations has been added in the caption. R1 and R2 have been marked in the (d) panel and have been mentioned in the caption. see the words marked in purple in the caption of Fig 2.
- Line 134: “As shown by Figure 1(d)” → “As shown in Figure 1(d)”
Answer: The word ‘by’ has been replaced by ‘in’ , see the word marked in purple in line 148.
- Line 155: “We can see that line of force…” → “We can see that lines of force…”
Answer: The word ‘line’ has been replaced by ‘lines’ , see the word marked in purple in line 173.
- Figure 3 , bottom: the south part of the arrow fan around the leading spot definitely shows the W->S->E direction, which is in agreements with Fig 7 in Pevtsov et al (Space Sci Rev (2014) 186:285–324 DOI 10.1007/s11214-014-0082-2 ) for the sketch-fibrils around the spot in the Northern hemisphere, which implies that the spot follows the HH rule. On the other hand, the sigmoid in Fig.2 (e,f,g) corresponds to the South hemisphere in Fig.7, which means that the AR does not obey the HH rule. I prone to believe to observations (sigmoid sense) and to agree with Authors that the AR does not follow the HH rule. Therefore, we have to accept that DOVE outcome (arrows) is not correct. Please check this point.
Answer: Yes, the AR does not obey the HH rule. It is in the Northern hemisphere and show positive chirality. However, the velocity field does not follow the direction of magnetic field lines. When a flux tube rising through the photosphere, a clockwise chirality of the magnetic field lines can result in a counterclockwise velocity field. This is in agreements with Fig 1 in Démoulin and Berger (2003) (Solar Physics 215: 203–215, (2003) DOI 10.1023/A:1025679813955) : The point where the tube crosses the photosphere moves with velocity uf , and the uf points in the opposite direction to Bt. So we believe that the DAVE outcome (arrows) is correct. A detailed introduction sentence is added to the text, as seen in the one marked in purple on line 205-209.
- Line 284: “ no significant pex potation”… What is “pex”?
Answer: Sorry, I misspelled “apex”, and now I have corrected it. See the word marked in purple in line 342.
- Line 298: “It is a significant twisted feature” → “It is a significantly twisted feature”
Answer: The word ‘significant’ has been replaced by ‘significantly’ , see the word marked in purple in line 346.
- Line 314: “a bidirectional QFP wave that support the magnetic…” → “a bidirectional QFP wave that supports the magnetic…”
I tried to correct errors, but I definitely missed some. Please pay a special attention to prepositions and plurals.
Answer: We correct the English errors, paying a special attention to prepositions and plurals. Thanks again.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThank authors for the responses. In my opinion, the improved version of the manuscript has achieved the standard of the journal of Universe.
Comments on the Quality of English LanguageIt is necessary for the minor editing of English language before the publishing.
Reviewer 3 Report
Comments and Suggestions for AuthorsThank you for addressing my concerns.
Comments on the Quality of English LanguageThe quality is satisfactory.
