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Statistical uncertainty analysis-based precipitation merging (SUPER) : A new framework for improved global precipitation estimation

Dong, Jianzhi ; Crow, Wade T. ; Chen, Xi ; Tangdamrongsub, Natthachet ; Gao, Man ; Sun, Shanlei ; Qiu, Jianxiu ; Wei, Lingna ; Gao, Hongkai and Duan, Zheng LU (2022) In Remote Sensing of Environment 283.
Abstract

Multi-source merging is an established tool for improving large-scale precipitation estimates. Existing merging frameworks typically use gauge-based precipitation error statistics and neglect the inter-dependence of various precipitation products. However, gauge-observation uncertainties at daily and sub-daily time scales can bias merging weights and yield sub-optimal precipitation estimates, particularly over data-sparse regions. Likewise, frameworks ignoring inter-product error cross-correlation will overfit precipitation observation noise. Here, a Statistical Uncertainty analysis-based Precipitation mERging framework (SUPER) is proposed for addressing these challenges. Specifically, a quadruple collocation analysis is employed to... (More)

Multi-source merging is an established tool for improving large-scale precipitation estimates. Existing merging frameworks typically use gauge-based precipitation error statistics and neglect the inter-dependence of various precipitation products. However, gauge-observation uncertainties at daily and sub-daily time scales can bias merging weights and yield sub-optimal precipitation estimates, particularly over data-sparse regions. Likewise, frameworks ignoring inter-product error cross-correlation will overfit precipitation observation noise. Here, a Statistical Uncertainty analysis-based Precipitation mERging framework (SUPER) is proposed for addressing these challenges. Specifically, a quadruple collocation analysis is employed to estimate precipitation error variances and covariances for commonly used precipitation products. These error estimates are subsequently used for merging all products via a least-squares minimization approach. In addition, false-alarm precipitation events are removed via a reference rain/no-rain time series estimated by a newly developed categorical variable merging method. As such, SUPER does not require any rain gauge observations to reduce daily random and rain/no-rain classification errors. Additionally, by considering precipitation product inter-dependency, SUPER avoids overfitting measurement noise present in multi-source precipitation products. Results show that the overall RMSE of SUPER-based precipitation is 3.35 mm/day and the daily correlation with gauge observations is 0.71 [−] – metrics that are generally superior to recent precipitation reanalyses and remote sensing products. In this way, we seek to propose a new framework for robustly generating global precipitation datasets that can improve land surface and hydrological modeling skill in data-sparse regions.

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author
; ; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Data merging, Error cross correlation, Precipitation, Rain/norain classification, Uncertainty analysis
in
Remote Sensing of Environment
volume
283
article number
113299
publisher
Elsevier
external identifiers
  • scopus:85140295542
ISSN
0034-4257
DOI
10.1016/j.rse.2022.113299
language
English
LU publication?
yes
id
75a21106-0c7a-4a17-8229-624a53586ade
date added to LUP
2022-12-06 11:37:52
date last changed
2023-05-10 11:04:06
@article{75a21106-0c7a-4a17-8229-624a53586ade,
  abstract     = {{<p>Multi-source merging is an established tool for improving large-scale precipitation estimates. Existing merging frameworks typically use gauge-based precipitation error statistics and neglect the inter-dependence of various precipitation products. However, gauge-observation uncertainties at daily and sub-daily time scales can bias merging weights and yield sub-optimal precipitation estimates, particularly over data-sparse regions. Likewise, frameworks ignoring inter-product error cross-correlation will overfit precipitation observation noise. Here, a Statistical Uncertainty analysis-based Precipitation mERging framework (SUPER) is proposed for addressing these challenges. Specifically, a quadruple collocation analysis is employed to estimate precipitation error variances and covariances for commonly used precipitation products. These error estimates are subsequently used for merging all products via a least-squares minimization approach. In addition, false-alarm precipitation events are removed via a reference rain/no-rain time series estimated by a newly developed categorical variable merging method. As such, SUPER does not require any rain gauge observations to reduce daily random and rain/no-rain classification errors. Additionally, by considering precipitation product inter-dependency, SUPER avoids overfitting measurement noise present in multi-source precipitation products. Results show that the overall RMSE of SUPER-based precipitation is 3.35 mm/day and the daily correlation with gauge observations is 0.71 [−] – metrics that are generally superior to recent precipitation reanalyses and remote sensing products. In this way, we seek to propose a new framework for robustly generating global precipitation datasets that can improve land surface and hydrological modeling skill in data-sparse regions.</p>}},
  author       = {{Dong, Jianzhi and Crow, Wade T. and Chen, Xi and Tangdamrongsub, Natthachet and Gao, Man and Sun, Shanlei and Qiu, Jianxiu and Wei, Lingna and Gao, Hongkai and Duan, Zheng}},
  issn         = {{0034-4257}},
  keywords     = {{Data merging; Error cross correlation; Precipitation; Rain/norain classification; Uncertainty analysis}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Remote Sensing of Environment}},
  title        = {{Statistical uncertainty analysis-based precipitation merging (SUPER) : A new framework for improved global precipitation estimation}},
  url          = {{http://dx.doi.org/10.1016/j.rse.2022.113299}},
  doi          = {{10.1016/j.rse.2022.113299}},
  volume       = {{283}},
  year         = {{2022}},
}