the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 24 Apr 2024
Improving the Estimate of Higher Order Moments from Lidar Observations Near the Top of the Convective Boundary Layer
Abstract. Ground-based lidar data have proven extremely useful for profiling the convective boundary layer (CBL). Many groups have derived higher order moments (e.g., variance, skewness, fluxes) from high temporal resolution lidar data using an autocovariance approach. However, these analyses are highly uncertain near the CBL top when the depth of the CBL (zi) is changing during the analysis period. This is because the autocovariance approach is usually applied to constant height levels and the character of the eddies are changing on either side of the changing CBL top. Here, a new approach is presented wherein the autocovariance analysis is performed on a normalized height grid, with a temporally smoothed zi. Output from a large eddy simulation model demonstrates that deriving higher order moments from time series on a normalized height grid has better agreement with the slab averaged quantities than the moments derived from the original height grid.
-
Notice on discussion status
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
-
Preprint
(2397 KB)
-
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
(2397 KB) - Metadata XML
- BibTeX
- EndNote
- Final revised paper
Journal article(s) based on this preprint
Interactive discussion
Status: closed
-
CC1: 'Comment on egusphere-2024-868', Fleur Couvreux, 22 May 2024
This manuscript proposes a methodology to improve the derivation of boundary-layer statistics from lidar observations. To do so, they propose to use the information derived from the observations but normalized by the boundary layer height before time-averaging. Although the subject is interesting, some modifications are needed before the manuscript is in the form for the definitive publication.
Introduction:
The introduction is well written, however a statement of the main objectives of the paper and the introduction of the outline are lacking.
Approach:
I suggest to repeat the same analysis, as shown in the paper, but for a certain amount of different locations sampled in the LES (instead of relying on outputs at only one given location) and then compute statistically the mean rmse of the difference between the computation over the regular grid and the one over the normalized grid to statistically demonstrate the improvement. The fact that the results rely on only one high-frequency time-serie is not completely convincing.
Results:
I propose to reduce slightly the number of figures. This can easily be done by combining Figures 2 and 3: you could just show the time-height variance for the slab and then only show the difference between the regular and slab and between the normalized and slab. Similarly for figures 4 and 5 and Figures 6 and 7.
Minor comments:
l 69: please change ‘derived three different ways’ to ‘derived through three different ways’
l 92: ‘Results’ should be a section and not a subsection
Citation: https://doi.org/10.5194/egusphere-2024-868-CC1 -
AC3: 'Reply on CC1', Tessa Rosenberger, 03 Aug 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-868/egusphere-2024-868-AC3-supplement.pdf
-
AC3: 'Reply on CC1', Tessa Rosenberger, 03 Aug 2024
-
RC1: 'Comment on egusphere-2024-868', Anonymous Referee #1, 06 Jun 2024
-
AC1: 'Reply on RC1', Tessa Rosenberger, 03 Aug 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-868/egusphere-2024-868-AC1-supplement.pdf
-
AC1: 'Reply on RC1', Tessa Rosenberger, 03 Aug 2024
-
RC2: 'Comment on egusphere-2024-868', Anonymous Referee #2, 07 Jul 2024
This work of Rosenberg et al. discusses a new approach to analyze higher-order moments of turbulent fluctuations in the convective boundary layer (CBL). Instead of normalizing the height range against the mean depth of the CBL in the analysis period (typically 30 minutes to 2 hours), the authors suggest a height grid normalized with a temporally smoothed depth of the CBL.
The authors base their analyses on large eddy simulation (LES) data of one day and discuss variance, skewness, and kurtosis of the turbulent fluctuations of water vapor mixing ratio as well as of vertical wind, and of the covariance of these two quantities, the latent heat flux (water vapor flux). Furthermore, they compare these simulated measurements of a vertical pointing lidar (one column measurements) with the data averaged over the whole domain of their model.
The manuscript is well written. I recommend accepting the manuscript after minor revision.
Specific comments:
Page 4, line 70ff: I think it would help if the authors added formulas to explain how they calculated the parameters for the three methods (more than just text). In addition, I suggest adding example plots of the three methods (or at least of the two lidar simulations) for a 1-hour example.
Introduction: Please add references to the statements in the first paragraph.
Figure 1: Please use the same nomenclature for the different parameters like in the text (line 74). ‘Blue’ should be ‘cyan’, ‘green’ is ‘black’. Mark local noon, sunrise, and sunset.
All figures: Please add labels (a), (b), (c).
Figure 2ff: Please define the white areas. I would prefer units at all color bars (instead of explaining the units of the color bars in the figure captions) and labels with the full parameter information (not just “Variance”, “Flux” etc.).
Table 1, 2, 3: You refer to RSME values but do not show these. I suggest that you also show the RSME data in the tables.
I think it would be better to use the same color scales for all plots of a figure, not different ones, so that it is easier to compare the results (Figs. 2, 6, 7). Same for the y scales in Figs. 8, 9, 10.
I would also prefer time scales with ticks at 6, 12, 18 h etc.(not at 5, 10, 15, 20 h). In addition, small ticks at each hour would be helpful.
Instead of “error”, I would prefer the term “uncertainty”.
Instead of “q flux” (Fig. 6) or “WVMR flux” (Fig. 10), I would prefer “latent heat flux”.
All units should be in normal font (not italic).
Citation: https://doi.org/10.5194/egusphere-2024-868-RC2 -
AC2: 'Reply on RC2', Tessa Rosenberger, 03 Aug 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-868/egusphere-2024-868-AC2-supplement.pdf
-
AC2: 'Reply on RC2', Tessa Rosenberger, 03 Aug 2024
Interactive discussion
Status: closed
-
CC1: 'Comment on egusphere-2024-868', Fleur Couvreux, 22 May 2024
This manuscript proposes a methodology to improve the derivation of boundary-layer statistics from lidar observations. To do so, they propose to use the information derived from the observations but normalized by the boundary layer height before time-averaging. Although the subject is interesting, some modifications are needed before the manuscript is in the form for the definitive publication.
Introduction:
The introduction is well written, however a statement of the main objectives of the paper and the introduction of the outline are lacking.
Approach:
I suggest to repeat the same analysis, as shown in the paper, but for a certain amount of different locations sampled in the LES (instead of relying on outputs at only one given location) and then compute statistically the mean rmse of the difference between the computation over the regular grid and the one over the normalized grid to statistically demonstrate the improvement. The fact that the results rely on only one high-frequency time-serie is not completely convincing.
Results:
I propose to reduce slightly the number of figures. This can easily be done by combining Figures 2 and 3: you could just show the time-height variance for the slab and then only show the difference between the regular and slab and between the normalized and slab. Similarly for figures 4 and 5 and Figures 6 and 7.
Minor comments:
l 69: please change ‘derived three different ways’ to ‘derived through three different ways’
l 92: ‘Results’ should be a section and not a subsection
Citation: https://doi.org/10.5194/egusphere-2024-868-CC1 -
AC3: 'Reply on CC1', Tessa Rosenberger, 03 Aug 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-868/egusphere-2024-868-AC3-supplement.pdf
-
AC3: 'Reply on CC1', Tessa Rosenberger, 03 Aug 2024
-
RC1: 'Comment on egusphere-2024-868', Anonymous Referee #1, 06 Jun 2024
-
AC1: 'Reply on RC1', Tessa Rosenberger, 03 Aug 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-868/egusphere-2024-868-AC1-supplement.pdf
-
AC1: 'Reply on RC1', Tessa Rosenberger, 03 Aug 2024
-
RC2: 'Comment on egusphere-2024-868', Anonymous Referee #2, 07 Jul 2024
This work of Rosenberg et al. discusses a new approach to analyze higher-order moments of turbulent fluctuations in the convective boundary layer (CBL). Instead of normalizing the height range against the mean depth of the CBL in the analysis period (typically 30 minutes to 2 hours), the authors suggest a height grid normalized with a temporally smoothed depth of the CBL.
The authors base their analyses on large eddy simulation (LES) data of one day and discuss variance, skewness, and kurtosis of the turbulent fluctuations of water vapor mixing ratio as well as of vertical wind, and of the covariance of these two quantities, the latent heat flux (water vapor flux). Furthermore, they compare these simulated measurements of a vertical pointing lidar (one column measurements) with the data averaged over the whole domain of their model.
The manuscript is well written. I recommend accepting the manuscript after minor revision.
Specific comments:
Page 4, line 70ff: I think it would help if the authors added formulas to explain how they calculated the parameters for the three methods (more than just text). In addition, I suggest adding example plots of the three methods (or at least of the two lidar simulations) for a 1-hour example.
Introduction: Please add references to the statements in the first paragraph.
Figure 1: Please use the same nomenclature for the different parameters like in the text (line 74). ‘Blue’ should be ‘cyan’, ‘green’ is ‘black’. Mark local noon, sunrise, and sunset.
All figures: Please add labels (a), (b), (c).
Figure 2ff: Please define the white areas. I would prefer units at all color bars (instead of explaining the units of the color bars in the figure captions) and labels with the full parameter information (not just “Variance”, “Flux” etc.).
Table 1, 2, 3: You refer to RSME values but do not show these. I suggest that you also show the RSME data in the tables.
I think it would be better to use the same color scales for all plots of a figure, not different ones, so that it is easier to compare the results (Figs. 2, 6, 7). Same for the y scales in Figs. 8, 9, 10.
I would also prefer time scales with ticks at 6, 12, 18 h etc.(not at 5, 10, 15, 20 h). In addition, small ticks at each hour would be helpful.
Instead of “error”, I would prefer the term “uncertainty”.
Instead of “q flux” (Fig. 6) or “WVMR flux” (Fig. 10), I would prefer “latent heat flux”.
All units should be in normal font (not italic).
Citation: https://doi.org/10.5194/egusphere-2024-868-RC2 -
AC2: 'Reply on RC2', Tessa Rosenberger, 03 Aug 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-868/egusphere-2024-868-AC2-supplement.pdf
-
AC2: 'Reply on RC2', Tessa Rosenberger, 03 Aug 2024
Peer review completion
Journal article(s) based on this preprint
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 326 | 118 | 32 | 476 | 17 | 17 |
- HTML: 326
- PDF: 118
- XML: 32
- Total: 476
- BibTeX: 17
- EndNote: 17
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1
Tessa Rosenberger
David D. Turner
Thijs Heus
Girish N. Raghunathan
Timothy J. Wagner
Julia Simonson
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
(2397 KB) - Metadata XML