the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 03 Sep 2024
Use of GPCC and GPCP Precipitation Products and GRACE and GRACE-FO Terrestrial Water Storage Observations for the Assessment of Drought Recovery Times
Abstract. Meteorological and hydrological processes depend on accurate precipitation observations. Most precipitation products utilize station-based observations directly or to bias correct satellite retrievals. Thus, the validation of station-based precipitation products requires further independent data. This study aims to assess the accuracy of the Global Precipitation Climatology Center (GPCC) and Global Precipitation Climatology Project (GPCP) precipitation products by estimating hydrological drought recovery time (DRT) from terrestrial water storage anomaly (TWSA) acquired from satellite gravimetry and the required precipitation amount across the five main Köppen-Geiger climate zones. Station-based precipitation products, namely GPCC Full Data Monthly Product v2022 and GPCP v3.2 Monthly Analysis Product, were utilized to estimate DRT. Additionally, the JPL mascon and G3P Total Water Storage (TWS) monthly-solutions from the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) satellite missions were also employed for the DRT estimation. DRT was estimated through the following two methods: (1) storage deficit, determined as the negative residual of detrended TWSA from its climatology, and (2) required precipitation amount, derived from the linear relationship between cumulative detrended smoothed precipitation anomaly (cdPA) and detrended TWSA. The results show no significant differences in the mean DRT estimations using GPCC and GPCP. Conversely, DRT estimation using JPL mascon is 2.6 months longer on average than that using G3P. The equatorial zone showed the shortest DRT estimation, 10.3 months, while the polar zone had the longest, 16.2 months. Except for the polar zone, the arid zone shows the highest DRT estimations, 13.9 months. Consistency in DRT estimations between the two methods was high across the different climate zones, with the equatorial zone exhibiting the highest, 97.8 %, and the polar zone the lowest, 74.9 %. Similar to mean DRT estimation results, the differences in consistency were not significant for the estimations obtained from GPCC and GPCP. In contrast, the G3P showed approximately 5.0 % higher consistency than the JPL mascon. The findings based on DRT estimations indicate a close agreement between GPCC and GPCP. Moreover, G3P was more consistent in DRT estimation with precipitation products than JPL mascon. These results provide necessary information for precipitation and TWSA product accuracy by using the hydrological drought characteristics, which helps in understanding the meteorological and hydrological processes.
- Preprint
(5143 KB) - Metadata XML
- BibTeX
- EndNote
Status: final response (author comments only)
-
RC1: 'Comment on egusphere-2024-2616', Anonymous Referee #1, 24 Oct 2024
1. Overview
The article proposes using Terrestrial Water Storage Anomalies (TWSA) from GRACE missions to independently evaluate precipitation products, specifically GPCC and GPCP, since traditional methods rely on gauge data used in the products' creation. By calculating Drought Recovery Times (DRT) with TWSA alone and combined with precipitation data, the authors aim to provide a more robust assessment of the alignment between precipitation products and TWSA.
2. Major comments
Throughout the article, I encountered many interesting results, but the core scientific analysis was lacking. It was unclear what these findings reveal, how they answer the research question, or how the new method clarifies the strengths and weaknesses of the precipitation products. Specifically, there is no discussion of contexts in which one product outperforms the other, nor an exploration of why this might be.
Additionally, the research question itself is not well-defined. While the abstract claims the goal is to evaluate precipitation products using TWSA data to calculate DRT, the paper sometimes shifts focus to evaluating TWSA products or comparing which precipitation/TWSA combination best estimates DRT.
To address this, I recommend: 1) clearly defining the research question in the introduction and maintaining alignment throughout, and 2) adding a discussion section (included in or separate from the " results " section) to interpret the results in light of the research question.
3. Minor comments
Abstract: Consider simplifying the abstract by emphasizing the key findings, rather than delving into specific details. This will help focus the reader's attention on the main outcomes without overwhelming them with too much information.
Line 28: You present the consistency results without explaining what they entail. Providing context here will help the reader understand the significance of these results.
Line 178: The detrending process would benefit from more explanation. Please consider adding details on the method used, along with a relevant reference.
Line 287: You describe the correlations over Australia (0.55), South America (0.46), and South Africa (ρ > 0.47) as “high.” Please clarify the criteria or thresholds you used to define these correlations as high.
Line 298: The text references Figures 2c and 2d, but these should be Figures 2b and 2d. Please adjust for accuracy.
Citation: https://doi.org/10.5194/egusphere-2024-2616-RC1 - AC1: 'Reply on RC1', E. Sinem Ince, 13 Nov 2024
-
RC2: 'Comment on egusphere-2024-2616', Anonymous Referee #2, 24 Oct 2024
The study is well-organized and innovative, with its originality stemming from the use of GRACE and GRACE-FO terrestrial water storage (TWS) data as an independent approach for evaluating the accuracy of precipitation products. The authors computed Drought Recovery Times (DRT) from Total Water Storage Anomaly (TWSA) data using two different approaches. The first approach, referred to as the "storage deficit" method, relies solely on TWSA data, while the second, the "required precipitation amount" method, integrates TWSA with precipitation data. Two TWSA products, JPL and G3P, were utilized for these calculations. Additionally, the authors evaluated the discrepancies in DRT results between the two TWSA products. I have only a few minor comments for the authors may consider:
Minor Comments:
-Line 285 : Which correlation method did you use, Can you please name it? (e.g. Pearson’s correlation)
-Line 298 : Please verify the figure numbers, as they might need to be labeled as 2b and 2d
-The paper uses numerous abbreviations and technical terms, so it is recommended to include a glossary of full forms for the abbreviations after the conclusion.
Overall, this research is well-structured and presents a state-of-the-art contribution to hydrology by highlighting the potential of GRACE and GRACE-FO data in evaluating precipitation products and drought characteristics. Addressing the minor comments provided will further strengthen the manuscript's impact.- AC2: 'Reply on RC2', E. Sinem Ince, 13 Nov 2024
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 213 | 35 | 10 | 258 | 3 | 2 |
- HTML: 213
- PDF: 35
- XML: 10
- Total: 258
- BibTeX: 3
- EndNote: 2
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1