the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 27 May 2024
Simulated Particle Evolution within a Winter Storm: Contributions of Riming to Radar Moments and Precipitation Fallout
Abstract. Remote sensing radars from air- and spaceborne platforms provide critical observations of clouds to estimate precipitation rates across the globe. Capability of these radars to detect changes in precipitation properties is advanced by Doppler measurements of particle fall speed. Within mixed-phase clouds, precipitation mass and its fall characteristics are especially sensitive to the effects of riming. In this study, we quantified these effects and investigated the distinction of riming from aggregation in Doppler radar vertical profiles using quasi-idealized particle-based model simulations. Observational constraints of a control simulation were determined from airborne in situ and remote sensing measurements collected during the Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) for a wintry-mixed precipitation event over the northeast United States on 04 February 2022. From the upper boundary of a one-dimensional column, particle evolution was simulated through vapor deposition, aggregation, and riming processes, producing realistic Doppler radar profiles. Despite a modest observed amount of supercooled liquid water (0.05 g m-3), riming accounted for 55 % of the ice-phase precipitation mass, cumulatively increasing reflectivity by 6.1 dB and Doppler velocity by 0.9 m s-1. Independent evaluation of process-based sensitivities showed that while radar reflectivity is comparably sensitive to either riming- or aggregation-based particle morphology, the Doppler velocity profile is uniquely sensitive to particle density changes during riming. Thus, Doppler velocity profiles advance the diagnosis of riming as a dominant microphysical process in stratiform clouds from single-wavelength radars, which has implications for quantitative constraints of particle properties in remote sensing applications.
- Preprint
(6190 KB) - Metadata XML
- BibTeX
- EndNote
Status: open (until 08 Jul 2024)
-
RC1: 'Comment on egusphere-2024-1480', Anonymous Referee #1, 18 Jun 2024
reply
General Comments:
The authors have done a great job on the manuscript titled “Simulated Particle Evolution within a Winter Storm: Contributions of Riming to Radar Moments and Precipitation Fallout”. The manuscript was a pleasure to read as it is well-written, clear, and well-organized. The authors have addressed important scientific questions, have understood well what previous work has been done on their research topic, and have presented work that adds a significant contribution beyond what has been done previously. I have only minor comments that should be easy to address.
Scientific questions/issues:
- It is probably good to briefly explain, in a sentence or two, the representativeness of this storm for an East Coast U.S. winter cyclone in Section 2.1. While this storm was a moderate storm with mixed precipitation that was stretched along a long frontal boundary (and was suited well for your study), a number of East Coast U.S. storms, including some on the IMPACTS project, were more intense with regions of elevated convection, strong frontal boundaries/circulations, deep-stratiform comma head clouds, and a variety of snowband patterns that evolved quickly with time. This will help add context for a reader that may not be too familiar with winter cyclones, especially over the East Coast.
Minor comments/technical:
- In Figure 4, I believe the y-axis should be labeled Height (km) not Height (m)
- I’m not sure this has to be done but I noticed Height km MSL is used in the text. However, on the figures, it’s Height (km). Again, may not be totally necessary, but just for consistency, use Height (km MSL) on the y-axis figure labels.
- Lines 471 – 472: You state the VD increased from -0.72 m s-1 to -1.00 m s-1. Technically that’s a decrease in value, correct? However, I also realize most readers will know what you mean, that the particles are falling faster. Perhaps adding a little to the sentence like: “VD increased from -0.72 m s-1 to -1.00 m s-1, meaning the particles fell faster” or something like that could help.
Citation: https://doi.org/10.5194/egusphere-2024-1480-RC1 -
AC1: 'Reply on RC1', Andrew DeLaFrance, 20 Jun 2024
reply
Thank you for the careful review of our manuscript. We look forward to addressing your specific concerns in our revised manuscript submission.
Including a comment on the representativeness of this event among East Coast U.S. winter cyclones is a great suggestion. The diversity in East Coast U.S. winter cyclones and classification of the events sampled during the IMPACTS project was recently discussed in Zaremba et al. (2024; https://doi.org/10.1175/JAS-D-23-0123.1). A reference to their discussion and a brief comment on characterization of this event will be added in our revision.
Regarding the technical concerns, the error in Figure 4 will be corrected and y-axis labels revised to read “Height (km MSL)”. The wording to describe the velocity change in lines 471-472 was also noted by Referee #2 as needing revision and we appreciate your suggested wording.
Citation: https://doi.org/10.5194/egusphere-2024-1480-AC1
-
RC2: 'Comment on egusphere-2024-1480', Anonymous Referee #2, 18 Jun 2024
reply
General Comments
Overall, the manuscript is well-structured, with an in-depth introduction laying the foundation for the goals and methods of the paper. The paper falls within the scope of ACP, while utilizing novel methods presented from past literature and unique in situ data to answer these questions. The experimental design is explained in a clear manner, and limitations arising from the methods are sufficiently addressed. I only have a few minor comments, as listed below:
Specific Comments
One of the key findings from this paper is demonstrating the usefulness of using VD to discriminate regions of significant riming from regions of aggregation or other microphysical processes. However, as the authors also acknowledge the uncertainty range of VD measured by the HIWRAP Ku-band (lines 502-503), it may be helpful to reiterate the importance of the relative change of VD with height, rather than the magnitude of VD, in the conclusions. In particular, given that all of the simulations shown in Figures 9 and 10 fall within the ±1 m s-1 range, a brief discussion of the robustness of the differences in the vertical derivative of VD may reduce any possible misinterpretation of the results presented in the paper.
Technical Corrections
Lines 471-472: consider rewording the phrase “VD increases from -0.72 m s-1 to -1.00 m s-1” to clarify that the speed is increasing, although the numerical value is becoming more negative.
Citation: https://doi.org/10.5194/egusphere-2024-1480-RC2 -
AC2: 'Reply on RC2', Andrew DeLaFrance, 20 Jun 2024
reply
We appreciate your review and the insightful comments on our manuscript. Indeed, there is uncertainty in the absolute magnitude of the HIWRAP VD measurements and for this reason, we emphasized relative changes throughout the manuscript. Some additional discussion on this uncertainty and the implications for interpretations from vertical profiles of VD to address the concerns raised in your comment will be added to the conclusion section of our revised manuscript.
The suggestion to reword the description of the change in velocity in lines 471-472 is consistent with Referee #1 and will be addressed in our revision.
Citation: https://doi.org/10.5194/egusphere-2024-1480-AC2
-
AC2: 'Reply on RC2', Andrew DeLaFrance, 20 Jun 2024
reply
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 188 | 46 | 18 | 252 | 8 | 8 |
- HTML: 188
- PDF: 46
- XML: 18
- Total: 252
- BibTeX: 8
- EndNote: 8
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1