Articles | Volume 26, issue 8
https://doi.org/10.5194/nhess-26-3749-2026
© Author(s) 2026. This work is distributed under the Creative Commons Attribution 4.0 License.
Can aerosols improve urban flood forecasting? A case study of 2015 Chennai extreme event
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- Final revised paper (published on 12 Aug 2026)
- Supplement to the final revised paper
- Preprint (discussion started on 31 Mar 2026)
- Supplement to the preprint
Interactive discussion
Status: closed
Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor
| : Report abuse
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RC1: 'Comment on egusphere-2026-1218', Mirela-Adriana Anghelache, 21 Jul 2026
- AC1: 'Reply on RC1', Oscar Paul, 01 Aug 2026
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RC2: 'Comment on egusphere-2026-1218', Anonymous Referee #2, 21 Jul 2026
- AC2: 'Reply on RC2', Oscar Paul, 01 Aug 2026
Peer review completion
AR – Author's response | RR – Referee report | ED – Editor decision | EF – Editorial file upload
ED: Publish subject to technical corrections (03 Aug 2026) by Leonard K. Amekudzi
AR by Oscar Paul on behalf of the Authors (03 Aug 2026)
Manuscript
This study investigates how aerosol concentrations, represented by cloud condensation nuclei (CCN), influence the simulation of an extreme precipitation and flood event over Chennai on 1 December 2015. Using coupled atmospheric, hydrologic, and hydraulic models with ensemble and large-eddy simulations, it shows that reduced CCN concentrations enhance warm-rain processes, improve rainfall timing and magnitude, and lead to more accurate flood predictions. The results highlight the importance of representing aerosol–cloud interactions in extreme precipitation forecasting and their potential value for improving urban flood management and reservoir operation decisions. Overall, the manuscript presents a valuable contribution to the field and is recommended for publication after several revisions to improve the clarity of some arguments and moderate a few claims. The manuscript should definitely include a Conclusions section.
At Chapter 4 - Discussion and Implications:
Cold pools can indeed strengthen with more precipitation—but you should explain the mechanism more clearly. For example: Enhanced warm-rain production increased precipitation reaching the lower tropospehere, where evaporatio of falling raindrops strengthebed cold pools ... just in order the explanations shouldn't be too abrupt.
Luine 12: LES experiments further supported these findings instead of LES experiments further demonstrated; demonstrated is quite strong.
Line 13: ....rainfall magnitude and timing, what abut their metrics?
Line 29: "... establishes quantitative aerosol microphysical plausibility ..."
"Plausibility" is not something typically quantified.
Instead:
- provides quantitative evidence for aerosol microphysical impacts, or
- provides quantitative support for aerosol microphysical efects, or
- quantifies the aerosol microphysical response
which sound much more natural.
Line 32: in EPF instead on EPF
I suggest replacing "prediction" with "forecasting" in the title. "Forecasting" is the more commonly used term in meteorological and hydrological applications and better reflects the operational implications discussed in the manuscript, particularly regarding improved rainfall forecasts and urban flood management.
As the study is based on a single hindcast of the 2015 Chennai flood event, future work should extend the analysis to other major Indian flood events (e.g., the 2005 Mumbai flood) to assess the robustness and generalizability of the proposed forecasting framework. This phrase can be included in the Conclusions, as well.