Maike Schumacher

Maike Schumacher
Aalborg University · Department of Development and Planning

Assistant Professor

About

50
Publications
11,112
Reads
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870
Citations
Additional affiliations
December 2020 - present
Aalborg University
Position
  • Professor (Assistant)
September 2018 - November 2020
University of Hohenheim
Position
  • Professor (Assistant)
October 2016 - August 2018
University of Bristol
Position
  • Research Associate
Education
October 2012 - September 2016
University of Bonn
Field of study
  • Geodesy
October 2010 - September 2012
University of Bonn
Field of study
  • Geodesy and Geoinformation
October 2007 - September 2010
University of Bonn
Field of study
  • Surveying, Geodesy and Geoinformation

Publications

Publications (50)
Article
Full-text available
Ionospheric models are applied for computing the Total Electron Content (TEC) in ionosphere to reduce its effects on the Global Navigation Satellite System (GNSS)-based Standard Point Positioning (SPP) applications. However, the accuracy of these models is limited due to the simplified model structures and their dependency on the calibration period...
Article
Full-text available
Global estimation of thermospheric neutral density (TND) on various altitudes is important for geodetic and space weather applications. This is typically provided by models, however, the quality of these models is limited due to their imperfect structure and the sensitivity of their parameters to the calibration period. Here, we present an ensemble...
Conference Paper
A method for estimating complex soil permittivity (or moisture) and penetration depth based on SAR decomposition is presented. By combining model- and eigenbased decomposition techniques in a non-iterative way, SAR observations are separated into single scattering components (soil, vegetation). The proposed method incorporates a multilayer rough su...
Conference Paper
The uncertainty in thermospheric neutral density (TND) estimates is one of the largest and persistent sources of uncertainty in orbit determination and prediction (OD/OP) of low Earth orbit space objects. The TNDs required for these applications are typically obtained from corresponding models. However, the simulation and forecasting skills of thes...
Conference Paper
The development of space-geodetic observation techniques has brought out a wide range of applications such as positioning and navigation, where the Global Navigation Satellite System (GNSS) is the main tools to provide surveying measurements in these applications. Though GNSS signals enable the calculation of receiver's position, some errors restri...
Article
Full-text available
With the upcoming L-band Synthetic Aperture Radar (SAR) satellite mission Radar Observing System for Europe L-band SAR (ROSE-L) and its integration into existing C-band satellite missions such as Sentinel-1, multi-frequency SAR observations with high temporal and spatial resolution will become available. The SARSense campaign was conducted between...
Article
Full-text available
WaterGAP is a global hydrological model that quantifies human use of groundwater and surface water as well as water flows and water storage and thus water resources on all land areas of the Earth. Since 1996, it has served to assess water resources and water stress both historically and in the future, in particular under climate change. It has impr...
Conference Paper
The upcoming launch of the L-band Synthetic Aperture Radar (SAR) satellite mission Radar Observing System for Europe L-band SAR (ROSE-L) will enable multi-frequency SAR observations when combined with existing C-band satellite missions (e.g., Sentinel-1). Due to the different penetration depths of the SAR signals, multi-frequency SAR offers great p...
Conference Paper
With the upcoming L-band Synthetic Aperture Radar (SAR) satellite mission Radar Observing System for Europe at L-band (ROSE-L) and its combination with existing C-band satellite missions such as Sentinel-1, multi-frequency SAR observations with high temporal and spatial resolution will become available. To investigate the potential for estimating s...
Article
Improving thermospheric neutral density (TND) estimates is important for computing drag forces acting on low-Earth-orbit (LEO) satellites and debris. Empirical thermospheric models are often used to compute TNDs for the precise orbit determination experiments. However, it is known that simulating TNDs are of limited accuracy due to simplification o...
Article
Full-text available
Climate variability and change along with anthropogenic water use have affected the (re)distribution of water storage and fluxes across the Contiguous United States (CONUS). Available hydrological models, however, do not represent recent changes in the water cycle. Therefore, in this study, a novel Bayesian Markov Chain Monte Carlo-based Data Assim...
Preprint
Full-text available
WaterGAP is a global hydrological model that quantifies human use of groundwater and surface water as well as water flows and water storage and thus water resources on all land areas of the Earth. Since 1996, it has served to assess water resources and water stress both historically and in the future, in particular under climate change. It has impr...
Article
Full-text available
Observing global terrestrial water storage changes (TWSCs) from (inter-)seasonal to (multi-)decade timescales is very important to understand the Earth as a system under natural and anthropogenic climate change. The primary goal of the Gravity Recovery And Climate Experiment (GRACE) satellite mission (2002-2017) and its follow-on mission (GRACE-FO,...
Conference Paper
Full-text available
Freshwater availability is of vital importance for humans, freshwater biota and ecosystem functions. In the past decades, global hydrological models (GHMs) were developed to improve understanding of the global freshwater situation in a globalized word, by filling gaps in observational coverage and assessing scenarios of the future under considerati...
Article
Full-text available
We demonstrate a new approach to recover water mass changes from GRACE satellite data at a daily temporal resolution. Such a product can be beneficial in monitoring extreme weather events that last a few days and are missing by conventional monthly GRACE data. The determination of the distribution of these water mass sources over networks of juxtap...
Article
Historically, hydrological models have been developed to represent land-atmosphere interactions by simulating water storage and water fluxes. These models, however, have their own unique characteristics (strength and weakness) in capturing different aspects of the water cycle, and their results are typically compared to or calibrated against in-sit...
Article
Glacial isostatic adjustment (GIA) is a crucial component in evaluating sea level change. The GIA process has been simulated globally from various physical forward models, and it can also be measured locally at some GPS stations. In this paper, we combine the physical model simulations and GPS measurements in a Bayesian hierarchical modeling framew...
Article
Droughts often evolve gradually and cover large areas, and therefore, affect many people and activities. This motivates developing techniques to integrate different satellite observations, to cover large areas, and understand spatial and temporal variability of droughts. In this study, we apply probabilistic techniques to generate satellite derived...
Article
In order to reduce high frequency non-tidal mass changes, while inverting for the Earth’s time-variable gravity fields from the Gravity Recovery And Climate Experiment (GRACE) measurements, it is usual to apply the Atmospheric and Oceanic De-aliasing (AOD1B) products. However, limitations in these products count as a potential threat to the accurac...
Article
Full-text available
Glacial isostatic adjustment (GIA) is the response of the solid Earth to past ice loading, primarily, since the Last Glacial Maximum, about 20 K yr BP. Modelling GIA is challenging because of large uncertainties in ice loading history and also the viscosity of the upper and lower mantle. GPS data contain the signature of GIA in their uplift rates b...
Article
Full-text available
Hydrological models are necessary tools for simulating the water cycle and for understanding changes in water resources. To achieve realistic model simulation results, real-world observations are used to determine model parameters within a “calibration” procedure. Optimization techniques are usually applied in the model calibration step, which assu...
Article
We introduce a framework for updating large scale geospatial processes using a model-data synthesis method based on Bayesian hierarchical modelling. Two major challenges come from updating large-scale Gaussian process and modelling non-stationarity. To address the first, we adopt the SPDE approach that uses a sparse Gaussian Markov random fields (G...
Poster
We propose the globalization of the continent-scale Kalman Filtering (KF) previously developed by Ramillien et al. (2015) to produce time series of daily maps of surface mass variations by progressive integration of daily geopoten-tial variations measured by orbiting satellites. These geopotential variations can be determined from very accurate int...
Article
Simulating hydrological processes within the (semi-)arid region of the Murray-Darling Basin (MDB), Australia, is very challenging specially during droughts. In this study, we investigate whether integrating remotely sensed terrestrial water storage changes (TWSC) from the Gravity Recovery And Climate Experiment (GRACE) mission into a global water r...
Article
Assimilation of terrestrial water storage (TWS) information from the Gravity Recovery And Climate Experiment (GRACE) satellite mission can provide significant improvements in hydrological modeling. However, the rather coarse spatial resolution of GRACE TWS and its spatially correlated errors pose considerable challenges for achieving realistic assi...
Article
The time-variable terrestrial water storage (TWS) products from the Gravity Recovery And Climate Experiment (GRACE) have been increasingly used in recent years to improve the simulation of hydrological models by applying data assimilation techniques. In this study, for the first time, we assess the performance of the most popular data assimilation...
Article
Full-text available
Previous studies indicate that water storage over a large part of the Middle East has been decreased over the last decade. Variability of the total (hydrological) water flux (TWF, i.e. precipitation minus evapotranspiration minus runoff) and water storage changes of the Tigris-Euphrates river basin and Iran's six major basins (Khazar, Persian, Urmi...
Poster
We propose a new method to produce time series of global maps of surface mass variations by integrating progressively daily geopotential changes measured by orbiting satellites. In the case of the Gravity Recovery And Climate Experiment (GRACE) mission, these geopotential variations can be determined from very accurate inter-satellite K-Band Range...
Article
Recently, ensemble Kalman filters (EnKF) have found increasing application for merging hydrological models with total water storage anomaly (TWSA) fields from the Gravity Recovery And Climate Experiment (GRACE) satellite mission. Previous studies have disregarded the effect of spatially correlated errors of GRACE TWSA products in their investigatio...
Article
Full-text available
Spatio-temporal patterns of hydrological droughts over the Greater Horn of Africa (GHA) are explored based on total water storage (TWS) changes derived from time-variable gravity field solutions of Gravity Recovery And Climate Experiment (GRACE, 2002–2014), together with those simulated by Modern Retrospective Analysis for Research Application (MER...
Article
Full-text available
Climate extremes such as droughts and intense rainfall events are expected to strongly influence global/regional water resources in addition to the growing demands for freshwater. This study examines the impacts of precipitation extremes and human water usage on total water storage (TWS) over the Ganges-Brahmaputra-Meghna (GBM) River Basin in South...
Article
Full-text available
Large-scale ocean-atmospheric phenomena like the El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) have significant influence on Australia's precipitation variability. In this study, multi-linear regression (MLR) and complex empirical orthogonal function (CEOF) analyses were applied to isolate (i) the continental precipitation varia...
Data
The uploaded movie shows precipitation anomalies over Australia that are likely due to ENSO/IOD. Maps are generated by applying a Complex Orthogonal Function (CEOF) technique following Forootan et al. (2016-Remote Sensing of Environment, doi:10.1016/j.rse.2015.10.027). Before applying CEOF, a 5-month moving average filter was applied to the monthly...
Chapter
Full-text available
An ensemble Kalman filter approach for improving the WaterGAP Global Hydrology Model (WGHM) has been developed, which assimilates Gravity Recovery And Climate Experiment (GRACE) data and calibrates the model parameters, simultaneously. The method uses the model-derived states and satellite measurements and their error information to determine updat...
Article
Full-text available
We introduce a new ensemble-based Kalman filter approach to assimilate GRACE satellite gravity data into the WaterGAP Global Hydrology Model. The approach (1) enables the use of the spatial resolution provided by GRACE by including the satellite observations as a gridded data product, (2) accounts for the complex spatial GRACE error correlation pat...
Article
Full-text available
There are two spurious jumps in the atmospheric part of the Gravity Recovery and Climate Experiment- Atmosphere and Ocean De-aliasing level 1B (GRACEAOD1B) products, which occurred in January-February of the years 2006 and 2010, as a result of the vertical level and horizontal resolution changes in the ECMWFop (European Centre for Medium-Range Weat...
Conference Paper
Full-text available
Temporal aliasing caused by incomplete reduction of background models is still a factor that affects the quality of the gravity field solutions derived from GRACE products. Our study addresses: (i) the computational aspect of the atmospheric de-aliasing (AD) products (de-aliasing aspect), and (ii) the biases caused by existing jumps in the atmosphe...
Article
Global hydrological models contribute to the understanding and quantification of the global water cycle. However, large model uncertainties persist due to insufficient model realism and climate forcing data not being available with sufficient spatial/temporal resolution on the global scale. The GRACE mission provides an independent observation of w...
Article
Global hydrological models contribute to the understanding and quantification of the global water cycle. However, large model uncertainties persist due to insufficient model realism and climate forcing and anthropogenic data not being available with sufficient spatial/temporal resolution on the global scale. The GRACE mission provides an independen...

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Projects

Projects (5)
Project
Developing efficient multi-sensor Data Assimilation frameworks for integrating Earth ObservatioN Satellite data into Land Surface Models (DANSk-LSM) FORSKNINGSPROJEKT 2 TEKNOLOGI OG PRODUKTION 2022 MODTAGEREhsan Forootan Aalborg Universitet BEVILGET BELØB 6.191.818 kr Klimaændringerne har øget sandsynligheden for hydrologiske og vejrekstreme begivenheder, som tørke og oversvømmelser. Den meteorologiske verdensorganisation (WMO) har fornylig i en rapport advaret om, at en tredjedel af verdens befolkning ikke er tilstrækkeligt dækket af advarselssystemer, og at antallet af mennesker, der vil være i nød efter naturkatastrofer, kan stige med 50% i løbet af det næste årti. Derfor vil vi, med projektet DANSk-LSM, opbygge banebrydende ”tidlig varsling”-systemer med høj kapacitet, der kan håndtere en høj beregningsbelastning, en række forskellige satellitdata og udvikle kontinentale hydrologiske assimilative systemer med hidtil uset opløsning. For at opnå de bedste resultater, vil vi udvikle tre modeller og forskellige strategier for dataassimilering og kalibrering. For at øge nøjagtigheden af modellerne, vil der for første gang blive anvendt frit tilgængelige satellitdata om: Terrestrisk vandlagring (TWS) fra satellitgravitation, overfladebundfugt (SSM) og landoverfladetemperatur (LST) samt overfladevandændringer. Open-access produkter fra DANSk-LSM vil omfatte: Kontinentale (på 100 m og 1 km) og globale (på 5 km opløsning) tørkeindekser, oplysninger om sværhedsgraden af hydrologiske våde og tørre globale forhold og deres returperioder samt kort over hydrologiske tørke og oversvømmelsespotentialer såvel som videnskabelige værktøjer til satellit-dataassimilering og nedskalering.
Project
In this project, we explore techniques to merge multi-sensor satellite data with Earth system models. The focus of our project is not only 1- on advancing the mathematical techniques, but also 2- on the application of data-model fusion techniques for real-world applications, such as developing continental drought/flood monitoring systems, as well as improving coupled land-surface-atmosphere models, and finally 3- on validation of data/models/techniques using independent sources.
Project
We explore techniques to merge multi-sensor earth observations and models