Terrestrial water storage in African Hydrological regimes derived from GRACE mission data

Intercomparison of spherical harmonics, mass concentration, and Scalar Slepian methods

Ashraf Rateb, Chung-Yen Kuo, Moslem Imani, Kuo Hsin Tseng, Wen Hau Lan, Kuo-En Ching, Tzu Pang Tseng

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Spherical harmonics (SH) and mascon solutions are the two most common types of solutions for Gravity Recovery and Climate Experiment (GRACE) mass flux observations. However, SH signals are degraded by measurement and leakage errors. Mascon solutions (the Jet Propulsion Laboratory (JPL) release, herein) exhibit weakened signals at submascon resolutions. Both solutions require a scale factor examined by the CLM4.0 model to obtain the actual water storage signal. The Slepian localization method can avoid the SH leakage errors when applied to the basin scale. In this study, we estimate SH errors and scale factors for African hydrological regimes. Then, terrestrial water storage (TWS) in Africa is determined based on Slepian localization and compared with JPL-mascon and SH solutions. The three TWS estimates show good agreement for the TWS of large-sized and humid regimes but present discrepancies for the TWS of medium and small-sized regimes. Slepian localization is an effective method for deriving the TWS of arid zones. The TWS behavior in African regimes and its spatiotemporal variations are then examined. The negative TWS trends in the lower Nile and Sahara at −1.08 and −6.92 Gt/year, respectively, are higher than those previously reported.

Original languageEnglish
Article number566
JournalSensors (Switzerland)
Volume17
Issue number3
DOIs
Publication statusPublished - 2017 Mar 10

Fingerprint

GRACE mission
Gravitation
spherical harmonics
Climate
scalars
Recovery
Water
water
Experiments
jet propulsion
Propulsion
leakage
Northern Africa
Leakage (fluid)
estimates
climate
Mass transfer
recovery
gravitation
trends

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Atomic and Molecular Physics, and Optics
  • Biochemistry
  • Instrumentation
  • Electrical and Electronic Engineering

Cite this

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title = "Terrestrial water storage in African Hydrological regimes derived from GRACE mission data: Intercomparison of spherical harmonics, mass concentration, and Scalar Slepian methods",
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Terrestrial water storage in African Hydrological regimes derived from GRACE mission data : Intercomparison of spherical harmonics, mass concentration, and Scalar Slepian methods. / Rateb, Ashraf; Kuo, Chung-Yen; Imani, Moslem; Tseng, Kuo Hsin; Lan, Wen Hau; Ching, Kuo-En; Tseng, Tzu Pang.

In: Sensors (Switzerland), Vol. 17, No. 3, 566, 10.03.2017.

Research output: Contribution to journalArticle

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AU - Rateb, Ashraf

AU - Kuo, Chung-Yen

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AU - Tseng, Kuo Hsin

AU - Lan, Wen Hau

AU - Ching, Kuo-En

AU - Tseng, Tzu Pang

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