Impact of tropical land convection on the water vapour budget in the tropical tropopause layer

Carminati, F.; Ricaud, P.; Pommereau, J.-P.; Rivière, E.; Khaykin, S.; Attié, J.-L.; Warner, J.

doi:https://doi.org/10.5194/acp-14-6195-2014

Articles | Volume 14, issue 12

https://doi.org/10.5194/acp-14-6195-2014

© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/acp-14-6195-2014

© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 14, issue 12

Research article

|

23 Jun 2014

Research article |

| 23 Jun 2014

Impact of tropical land convection on the water vapour budget in the tropical tropopause layer

F. Carminati, P. Ricaud, J.-P. Pommereau, E. Rivière, S. Khaykin, J.-L. Attié, and J. Warner

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Final revised paper (published on 23 Jun 2014)
Preprint (discussion started on 18 Dec 2013)

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

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RC C10296: 'comments to “impact of tropical land convection on the water vapour budget in the tropical tropopause layer” by Carminati et al. submitted to Atmospheric Chemistry and Physics', Anonymous Referee #1, 20 Dec 2013
- AC C13204: 'Authors’ response to Referee #1 on “Impact of tropical land convection on the water vapour budget in the Tropical Tropopause Layer"', Fabien Carminati, 31 Mar 2014
RC C12199: 'Comments on "Impact of Tropical Land Convection on the Water Vapour Budget in the Tropical Tropopause Layer" by F. Carminati et al.', Anonymous Referee #2, 14 Feb 2014
- AC C13219: 'Authors’ response to Referee #2 on “Impact of tropical land convection on the water vapour budget in the Tropical Tropopause Layer"'', Fabien Carminati, 31 Mar 2014
RC C12371: 'Interactive comments on “Impact of tropical land convection on the water vapour budget in the Tropical Tropopause Layer” by F. Carminati et al.', Anonymous Referee #3, 17 Feb 2014
- AC C13243: 'Authors’ response to Referee #3 on “Impact of tropical land convection on the water vapour budget in the Tropical Tropopause Layer"''', Fabien Carminati, 31 Mar 2014

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by Fabien Carminati on behalf of the Authors (01 Apr 2014) Author's response Manuscript

ED: Referee Nomination & Report Request started (11 Apr 2014) by Peter Haynes

RR by Anonymous Referee #3 (17 Apr 2014)

RR by Anonymous Referee #1 (21 Apr 2014)

Suggestions for revision or reasons for rejection

General comments:
After revision, I think the science part is good. Writing can still be tuned better.
Recommendation: minor revision
Minor comments:

1. P1, L 29. Larger day vs. night differences in the water vapor do not prove the stronger convective intensity. There are other factors that could play here, such as the diurnal variation phase differences, the local RH. Yes, you provided some RH graphs in the TTL, but how reliable are those? Even after you can clear out all those factors, you still cannot claim convective intensity is more vigorous in the southern tropics. All you could claim is that convection in southern tropics could have a larger impact on the TTL. Large impact ≠ stronger convection.
2. P5, L15, there are multiple places using “Figure”, other places use “Fig.”, pick one style and be consistent
3. Fig. 3 has never been mentioned in the text. Why do we need that figure? Same applies to Fig. 5.
4. Fig. 8, what is the unit of color scale? Top and bottom panels have different color scales, not sure how to compare them.
5. Fig.6-8. I notice a seasonal phase shift of troposphere and stratosphere H2O at 125. It seems that the tropospheric H2O is peaking a slightly earlier every year. Is this real or just artifact of filtering? It urges the explanation.
6. P13, L5, extra “the”.
7. P14, large D-N water vapor means stronger convection? I am not quite sure if this is a solid reasoning.
8. P18, L2-3, separating the samples over land and ocean should not be difficult over these regions. However, the horizontal mixing would kill a lot of diurnal signal. I am not sure why mixing land and ocean would remove the diurnal signal if you have much stronger signal from land, unless you have dominate oceanic samples.
9. The larger impact of convection on the TTL in southern tropics may be from the diurnal variation differences between Northern part and southern part of the continents. Northern Amazon could have diurnal peaks early and southern Amazon have more of large organized systems with influences to later time. Similar reason applies to the Sahel vs. Congo in Africa. What if more large mesoscale convectie systems could be found over Congo than Sahel (especially your box does not include west Sahel, where MCSs develops/matures), which leads to higher H2O amount to late evening. That does not necessarily mean convection over Congo is stronger than Sahel.

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RR by Anonymous Referee #2 (24 Apr 2014)

Suggestions for revision or reasons for rejection

The authors have addressed all of my major concerns. In my opinion, the paper is suitable for publication subject to some minor revisions:

p.8, l.18-20: I agree with your conclusion that the D-N difference is likely not an artefact generated by the a priori, but I am not sure that it is appropriate to conclude from one year of a priori that the amplitude of the retrieved D-N at different levels are "almost certainly" under or overestimated. I would recommend either removing these statements or using less confident language (e.g., "may be").

p.13, l.14-15: You write "Assuming that the daytime and the night-time MLS precisions are similar" -- could this assumption be verified, at least to leading order, by comparing the provided precision values for day and night profiles?

p.13, l.17: I'm not sure that your exact meaning is clear here. Do the large number of near-zero cases really produce an underestimation of the D-N amplitude? If many of the differences are near zero, doesn't this suggest that the mean amplitude could also be near zero?

p.13, l.21: What is the justification for using 10% as the significance threshold, and for applying the same threshold at all three levels? Please provide a basis for using 10%, or (ideally) a more objective threshold.

p.13, l.24-25: If the convective influences act mainly in the vertical direction, then the significant D-N differences at higher levels should presumably be largely consistent with the significant D-N differences at lower levels. For example, are more than 80% of the days with significant D-N differences at 100 hPa also days with significant differences at 177 hPa? The discussion in Section 4.2 suggests yes, but it might be worth checking. Also, you may want to specify the collocation criteria for both day and night to be available -- is it just that you have some day and night retrievals within the 10°x10° grid?

p.16, l.11: "aivailable" -> "available"

p.18, l.18: "7.10^6" -> "7 x 10^6"?

p.18, l.20: "CloutSat" -> "CloudSat"

Fig. 1: You may want to remove the drop shadows from this diagram.

Figs. 9 and 10: The red and green lines may be difficult to distinguish for some readers, especially for Fig. 10. One option would be to make temperature red and water vapor blue (many readers will expect this colour scheme anyway), and then make IWC grey so that it is more easily distinguished.

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ED: Reconsider after minor revisions (Editor review) (25 Apr 2014) by Peter Haynes

AR by Fabien Carminati on behalf of the Authors (05 May 2014) Author's response Manuscript

ED: Publish subject to technical corrections (17 May 2014) by Peter Haynes

AR by Fabien Carminati on behalf of the Authors (19 May 2014) Author's response Manuscript