|They have removed much of the questionable analyses and thus the paper is more carefully presented. It is less interesting as a result although I guess the 18 hour periodicity observation could merit a short note in ACP. I have one more very significant concern- namely their wind result, and specifically Figure 9b, is simply not credible. Consider that they have only 4 days of useable data with a 6 hour integration time. That means they have 16 points. And with 16 points, they are claiming to resolve about 5 oscillations of the 18 hour wave? This is very hard to believe even for a stationary amplitude. But to show time dependence like in Figure 9b? The uncertainties in the spectral domain have to be enormous. The slightest bit of non-stationarity, for example, will, I believe, completely invalidate their results. Further, a detailed look at Figure 9 shows it to not be consistent with Figure 4. Thus above 0.2 hpa, Figure 4 shows a white area meaning no data on Dec 5. So at the highest altitudes, they have less than 16 points. One suggestion is to limit themselves to the pressure domain from 0.5 to 1.0 hpa where they have 7 days of data. |
Other than the above, I have a few other minor comments plus some technical/grammar corrections.
1. On line 2, page 4, they state that they retrieved zonal and meridional winds, but show only the zonal component. What about the meridional component?
2. They mention meridional gradients in the H2O as possibly resulting from the edge of the polar vortex (line 10, page 8). I would argue that vertical gradients are equally if not more deserving of mention. They would not be expected to see oscillations in the H2O for pressures higher than about 0.2 hpa because the vertical gradient in the H2O becomes so weak. This means that the altitude variation of the 18 hour wave in H2O and in particular, a comparison with the wind results in Figure 9, is misleading. But then again, Figure 9b has bigger problems as per my top comment.
3. What are the vertical hash lines in Figures 2 and 3?
4. Grammar: line 18, page 3: say “A typical range for the threshold for the ….”
5. Grammar: line 22, page 3: “significantly”
6. Page 6, line 26: delete “water vapor”, saying “climatology as a priori information” is clear without redundancy
7. Page 6, line 28, whats Ac?
8. Figure 11 in general- I am very confused. If the a priori is seasonally varying, and only seasonally varying, why do they get any kind of short term oscillations as shown in the Figure? Why not use monthly averaged a priori, then the question of short term (quasi 2 day) oscillations becomes moot.
9. Continued of the above- line 31, page 6. This is unsubstantiated.