With this cover letter, we will submit the revid manuscript (acp-2010-399) entitled, “Relating tropical ocean clouds to moist process using water vapor isotope measurements” for publication in Atmospheric Chemistry and Physics. We would like to thank referees for the careful and constructive reviews. Bad the comments from the referees, we have made changes of the manuscript, which are detailed below.
Reply to the evaluation by the cond referee
This reviewer pointed out two things. We believe the two points are relevant to comments from first reviewer and following his/her minor comments.
1.Table 1: Is it valid to show the number of lower nsitivity data? (Specifically, BLC and PC data for 850-500 hPa)鲈鱼清蒸
寻淮州
Answer: This point is related to our answer to the first referee. Plea e our respons and Appendix to the first reviewer above.
2. Figure 1: What are the multiple lines in the same colors?简单微信昵称
Answer: The multiple lines in the same color are multiple profile obrvations in one TES Run ID (5889)
except precipitating clouds (Three Run IDs, 5889, 5918 and 5948 were need to plot multiple profile obrvations).
3. Figure 2: Latitude/Longitude information should be added. Is this a snapshot? If so, the date should be specified.
初程>解理面
Answer: We add the date in the figure caption. The geographical information was already prented in the original manuscript.
4. Figure 3: Time information should be specified in the caption. Why COD/CTP and H2O/dD have different sampling frequencies? How can the reader know about the cloud types during this time ries?
Answer: In Fig. 3, cloud properties (a and b) and water vapor (c and d) have different sampling frequencies becau we sampled cloudy conditions for Fig. 3 (a) and (b). We add a ntence in figure caption.
5. Figure 4: Is it a snapshot? Seasonal mean for a single year? Climatology? Plea clarify.
Answer: We mentioned sampling period in Section 2.2. Isotopic composition of water vapor (δD). It i中华酒文化
s not a snapshot. It is a asonal mean value (June to August, JJA) from June 2005 to August 2008.
6. Abstract: It has been told by many that the vapor-dD relationship is controlled by not only Rayleigh process but also other non-Rayleigh process, but none of them has quantified the significance. Is it still impossible in this study?
Answer: It is a good point. One of the simplest models for atmospheric water vapor isotope is bad on the Rayleigh distillation equation. Several process could potentially change the isotopic composition of water vapor, such as mixing, subsidence and re-evaporation (non-Rayleigh process) as we described in our manuscript. Quantifying the significance is beyond our scope of the study. However, some studies using remotely nd data and/or in-situ measurements have been ud to constrain humidity dynamics of lower troposphere. For example, Worden et al. (2007) quantitatively showed the contribution of rainfall evaporation to lower tropospheric humidity. Galewsky et al. (2007) reproduced the clear-sky free troposphere relative humidity and D/H ratios using a model that accounts for large-scale condensation, fractionation, mixing and transport of water vapor, which Rayleigh distillation model underpredicted.
Galewsky, J., Strong, M., and Sharp, Z. D.: Measurements of water vapor D/H ratios from Mauna Kea, Hawaii, and implications for subtropical humidity dynamics,
Geophys. Res. Lett., 34, L22808, doi:10.1029/2007GL031330, 2007.
7. P17412 top: What is the unit of COD?
Answer: Cloud Optical Depth is unit-less.
8. P17414 bottom: Why do the ranges of the lines in Fig 1e-h link to the nsitivity? What is the each single line in the figure 1e-h? What is difference between error and nsitivity in this context?
使用用英语怎么说Answer: If there is little nsitivity, there would be no difference between TES a priori constraint and an estimate. Each line reprents a single obrvation measured by TES in Fig. 1e-h.
9. P17415 middle: What is “step-and-stare”? Describe.
Answer: “Step-and Stare” is a TES obrvation mode in which 60 measurements are made spaced about 35km apart. “Stare” means point at a specific latitude and longitude for up to 210 conds. “Tranct” means a t of exactly contiguous latitudes and longitudes in a line up to 885 km long. We added the definition of “step and stare” in the manuscript. Now it becomes “A TES “step-and-stare”, which is a t of nadir footprint spaced about 35 km apart, was conducted during this same time and the approximate orbit location of this t of obrvations is shown as a vertical red line over
the MODIS imagery.”.
10. P17416 middle: “less than 0.1” -> No COD data is less than 0.1 in Figure 3.
Answer: Fixed. Now the ntence is “Near –3°, the air is relatively dry, approximately 1 g/kg but also very isotopically depleted underneath high cirrus (cloud-top pressure near 200 hPa, but cloud optical depth less than 1.0).”.
11. P17419 bottom: “The first distribution is for ” -> I don’t e any clear sky and non-precipitation cloud distributions in the figure 6.
Answer: The ntence in Page 17419, lines 28 and 29 ems to be confusing such that we have added more information. Now it becomes “The first distribution (850-500hPa) is for comparison against the clear sky and nonprecipitating cloud distributions shown in Fig. 5 and shows that the air above boundary layer clouds is more isotopically depleted than air parcels associated with clear sky and nonprecipitating clouds.”.
12. P17420: This explanation is particularly hard to follow. At top, it reads “well explained by local mixing”, but at middle, it reads “due to less frequent mixing”. Which is true? I may misunderstand it,
but to avoid such misunderstanding, it’d be better for the authors to make the explanation easier. Using schematic figures is absolutely necessary.
Answer: The TES obrvations show that the air above boundary layer clouds is constrained by the two theoretical lines. However, compared to the clear and nonprecipitating clouds, the overall isotopic composition of water vapor for boundary layers are more depleted in heavy isotope (Table 1). We tried to explain this isotopic depletion in the ntence in page 17420, line 5. To address the criticism of this reviewer, we reworded the paragraph in Page 17420, lines 3 to 11 to make that clearer. Now the paragraph becomes “We can conclude from either distribution that the TES obrvations above boundary layer clouds are well constrained by local mixing and Rayleigh condensation.”. Since Steven (2005) described each type of clouds in detail using cartoons, we believe it is not necessary to add a cartoon in this manuscript.
随时约
We appreciate the comments from the reviewers. Thank you for reviewing our manuscript.
Sincerely,
Jeonghoon Lee
