Simulated estimation of hydrological loads from GRACE

Seo, Ki‐Weon; Wilson, Clark R.

doi:10.1007/s00190-004-0410-5

Cited by 48 publications

(60 citation statements)

References 12 publications

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“…we used two GRACE datasets using different filtering algorithms (Chen et al 2005;Seo and Wilson 2005). These two datasets contain 20 months starting from August 2002 to July 2004 with four months missing in between.…”

Section: Figmentioning

confidence: 99%

Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

Niu

Yang

2006

Journal of Hydrometeorology

441

397

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The presence of ice in soil dramatically alters soil hydrologic and thermal properties. Despite this important role, many recent studies show that explicitly including the hydrologic effects of soil ice in land surface models degrades the simulation of runoff in cold regions. This paper addresses this dilemma by employing the Community Land Model version 2.0 (CLM2.0) developed at the National Center for Atmospheric Research (NCAR) and a simple TOPMODEL-based runoff scheme (SIMTOP). CLM2.0/ SIMTOP explicitly computes soil ice content and its modifications to soil hydrologic and thermal properties. However, the frozen soil scheme has a tendency to produce a completely frozen soil (100% ice content) whenever the soil temperature is below 0°C. The frozen ground prevents infiltration of snowmelt or rainfall, thereby resulting in earlier-and higher-than-observed springtime runoff. This paper presents modifications to the above-mentioned frozen soil scheme that produce more accurate magnitude and seasonality of runoff and soil water storage. These modifications include 1) allowing liquid water to coexist with ice in the soil over a wide range of temperatures below 0°C by using the freezing-point depression equation, 2) computing the vertical water fluxes by introducing the concept of a fractional permeable area, which partitions the model grid into an impermeable part (no vertical water flow) and a permeable part, and 3) using the total soil moisture (liquid water and ice) to calculate the soil matric potential and hydraulic conductivity. The performance of CLM2.0/SIMTOP with these changes has been tested using observed data in cold-region river basins of various spatial scales. Compared to the CLM2.0/SIMTOP frozen soil scheme, the modified scheme produces monthly runoff that compares more favorably with that estimated by the University of New Hampshire-Global Runoff Data Center and a terrestrial water storage change that is in closer agreement with that measured by the Gravity Recovery and Climate Experiment (GRACE) satellites.

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Section: Figmentioning

confidence: 99%

Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

Niu

Yang

2006

Journal of Hydrometeorology

441

397

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“…For example, Swenson and Wahr (2002) proposed a Lagrange multiplier method to optimize water storage extractions for interested basins. Seo and Wilson (2005) developed dynamic basin functions with timevariable weightings based on climate models, which could notably improve the GRACE spatial resolution.…”

Section: Introductionmentioning

confidence: 99%

Attenuation effect on seasonal basin-scale water storage changes from GRACE time-variable gravity

Chen

Wilson

Famiglietti

et al. 2006

J Geod

Self Cite

103

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In order to effectively recover surface mass or geoid height changes from the gravity recovery and climate experiment (GRACE) time-variable gravity models, spatial smoothing is required to minimize errors from noise. Spatial smoothing, such as Gaussian smoothing, not only reduces the noise but also attenuates the real signals. Here we investigate possible amplitude attenuations and phase changes of seasonal water storage variations in four drainage basins (Amazon, Mississippi, Ganges and Zambezi) using an advanced global land data assimilation system. It appears that Gaussian smoothing significantly affects GRACE-estimated basinscale seasonal water storage changes, e.g., in the case of 800 km smoothing, annual amplitudes are reduced by about 25-40%, while annual phases are shifted by up to 10 • . With these effects restored, GRACE-estimated water storage changes are consistently larger than model estimates, indicating that the land surface model appears to underestimate terrestrial water storage change. Our analysis based on simulation suggests that normalized attenuation effects (from Gaussian smoothing) on seasonal water storage change are relatively insensitive to the magnitude of the true signal. This study provides a numerical approach that can be used to restore seasonal water storage change in the basins from spatially smoothed GRACE data.

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“…Contrarily, a filter with a perfect spectral localization, such as that realized by a cumulative spherical harmonic spectrum, is associated with a highly oscillating spatial window. The construction of local basin filters is extensively discussed in the literature (e.g., Swenson and Wahr 2002;Seo and Wilson 2005).…”

Section: Appendix 2: Local Error Estimatesmentioning

confidence: 99%

Earth System Mass Transport Mission (e.motion): A Concept for Future Earth Gravity Field Measurements from Space

et al. 2012

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In the last decade, satellite gravimetry has been revealed as a pioneering technique for mapping mass redistributions within the Earth system. This fact has allowed us to have an improved understanding of the dynamic processes that take place within and -012-9209-8 between the Earth's various constituents. Results from the Gravity Recovery And Climate Experiment (GRACE) mission have revolutionized Earth system research and have established the necessity for future satellite gravity missions. In 2010, a comprehensive team of European and Canadian scientists and industrial partners proposed the e.motion (Earth system mass transport mission) concept to the European Space Agency. The proposal is based on two tandem satellites in a pendulum orbit configuration at an altitude of about 370 km, carrying a laser interferometer inter-satellite ranging instrument and improved accelerometers. In this paper, we review and discuss a wide range of mass signals related to the global water cycle and to solid Earth deformations that were outlined in the e.motion proposal. The technological and mission challenges that need to be addressed in order to detect these signals are emphasized within the context of the scientific return. This analysis presents a broad perspective on the value and need for future satellite gravimetry missions.

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Simulated estimation of hydrological loads from GRACE

Cited by 48 publications

References 12 publications

Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

Attenuation effect on seasonal basin-scale water storage changes from GRACE time-variable gravity

Earth System Mass Transport Mission (e.motion): A Concept for Future Earth Gravity Field Measurements from Space

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