A5060111105- Geophysics and Gravity Measurements
- Geomagnetism and Paleomagnetism Studies
- GNSS positioning and interference
- Solar and Space Plasma Dynamics
- Oceanographic and Atmospheric Processes
- Reservoir Engineering and Simulation Methods
- Ionosphere and magnetosphere dynamics
- Methane Hydrates and Related Phenomena
- Hydrology and Watershed Management Studies
- Polyamine Metabolism and Applications
- Amino Acid Enzymes and Metabolism
- Geophysical and Geoelectrical Methods
- Inertial Sensor and Navigation
- Cryospheric studies and observations
- Climate variability and models
- Flood Risk Assessment and Management
- Computational Physics and Python Applications
- Ocean Waves and Remote Sensing
- Geological and Geophysical Studies
- Hydrology and Drought Analysis
- Statistical and numerical algorithms
- Meteorological Phenomena and Simulations
- Spacecraft Design and Technology
- Arctic and Antarctic ice dynamics
- Planetary Science and Exploration
University of Bonn
2016-2025
Institute of Geodesy and Geophysics
2013-2025
GeoInformation (United Kingdom)
2023-2024
GFZ Helmholtz Centre for Geosciences
2005-2021
Wuhan University
2021
Delft University of Technology
2002-2009
In-Q-Tel
2001-2003
University of Cologne
1983-1989
Lungenklinik Köln-Merheim
1986-1988
Krankenhaus Köln-Holweide
1988
We discuss a new method for approximately decorrelating and non-isotropically filtering the monthly gravity fields provided by recovery climate experiment (GRACE) twin-satellite mission. The procedure is more efficient than conventional Gaussian-type isotropic filters in reducing stripes spurious patterns, while retaining signal magnitudes. One of problems that users GRACE level 2 field solutions fight effect increasing noise higher frequencies. Simply truncating spherical harmonic solution...
Significance Understanding sea-level change is of paramount importance because it reflects climate-related factors, such as the ocean heat budget, mass changes in cryosphere, and natural ocean/atmosphere variations. Furthermore, rise directly affects coastal areas, which has ramifications for its population economy. From a novel combination Gravity Recovery And Climate Experiment radar altimetry data we find over last 12 y: ( i ) larger global steric previously reported, ii contribution to...
The satellite‐only gravity field model GOCO01S is a combination solution based on 61 days of GOCE gradient data, and 7 years GRACE GPS K‐band range rate resolved up to degree/order 224 harmonic series expansion. was performed consistently by addition full normal equations stochastic modeling observations. has been validated against external global models regional GPS/leveling While low medium degrees are mainly determined GRACE, significant contributions the new measurement type gradients...
Abstract. Droughts continue to affect ecosystems, communities and entire economies. Agriculture bears much of the impact, in many countries it is most heavily affected sector. Over past decades, efforts have been made assess drought risk at different spatial scales. Here, we present for first time an integrated assessment both irrigated rainfed agricultural systems global scale. Composite hazard indicators were calculated separately using indices based on historical climate conditions...
Abstract The Gravity Recovery and Climate Experiment (GRACE) mission has monitored global total water storage anomalies (TWSA) with an unprecedented accuracy since 2002. Yet, many applications require a longer record, that is, extending prior to the GRACE period. Here, we present new reconstruction of long‐term (1979–2020) TWSA fields by combining machine learning time series decomposition statistical techniques. We find reconstructed from fits well GRACE‐FO observation over most grids (0.5°...
The regular drought episodes in South Africa highlight the need to reduce risk by both policy and local community actions. Environmental socioeconomic factors Africa's agricultural system have been affected past, creating cascading pressures on nation's agro-economic water supply systems. Therefore, understanding key drivers of all components through a comprehensive assessment must be undertaken order inform proactive management. This paper presents, for first time, national irrigated...
Abstract Several researchers have postulated that, under a changing climate due to anthropogenic forcing, an intensification of the water cycle is already way. This usually related increases in hydrological fluxes as precipitation (P), evapotranspiration (E), and river discharge (R). It debate, however, whether such observed or reconstructed flux changes are real on what scales. Large‐scale increase decrease deficit (P‐E‐R), i.e., that do not compensate, would lead acceleration deceleration...
Abstract The Gravity Recovery and Climate Experiment (GRACE) mission ended its operation in October 2017, the GRACE Follow‐On was launched only May 2018, leading to approximately 1 year of data gap. Given that GRACE‐type observations are exclusively providing direct estimates total water storage change (TWSC), it would be very important bridge gap between these two missions. Furthermore, for many climate‐related applications, is also desirable reconstruct TWSC prior period. In this study, we...
Abstract Sea-level rise is beginning to cause increased inundation of many low-lying coastal areas. While most Earth’s areas are at risk, that will be affected first characterized by several additional factors. These include regional oceanographic and meteorological effects and/or land subsidence relative sea level faster than the global average. For catastrophic flooding, when wind-driven storm surge inundates large areas, contribution sea-level frequency these events difficult evaluate....
Abstract Accurate estimates of ocean mass change are necessary to infer steric sea level from changes measured with satellite altimeters. Published studies using the Gravity Recovery and Climate Experiment (GRACE) mission indicated a large range in trends (∼1–2 mm/year) reported standard errors 0.1–0.3 mm/year. Here we show that part this discrepancy (up 0.6 can be explained by which model is used account for effect glacial isostatic adjustment (GIA). The second largest contribution (0.3–0.4...
Abstract We describe the new global land water storage data set GLWS2.0, which contains total anomalies (TWSA) over except for Greenland and Antarctica with a spatial resolution of 0.5 $$^\circ $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow/> <mml:mo>∘</mml:mo> </mml:msup> </mml:math> , covering time frame 2003 to 2019 without gaps, including monthly uncertainty quantification. GLWS2.0 was derived by assimilating GRACE/-FO mass change maps into WaterGAP...
Monitoring hydrological redistributions through their integrated gravitational effect is the primary aim of Gravity Recovery and Climate Experiment (GRACE) mission. Time‐variable gravity data from GRACE can be uniquely inverted to hydrology, since mass transfers located at or near Earth's surface are much larger on shorter timescales than those taking place within deeper Earth because one remove contribution atmospheric masses air pressure data. Yet it has been proposed that scales this may...