The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
J A Huisman - One of the best experts on this subject based on the ideXlab platform.
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monitoring and modeling the Terrestrial System from pores to catchments the transregional collaborative research center on patterns in the soil vegetation atmosphere System
Bulletin of the American Meteorological Society, 2015Co-Authors: Clemens Simmer, Insa Thieleeich, M Masbou, Wulf Amelung, Heye Bogena, Susanne Crewell, Bernd Diekkruger, Frank Ewert, Harriejan Hendricks Franssen, J A HuismanAbstract:AbstractMost activities of humankind take place in the transition zone between four compartments of the Terrestrial System: the unconfined aquifer, including the unsaturated zone; surface water; vegetation; and atmosphere. The mass, momentum, and heat energy fluxes between these compartments drive their mutual state evolution. Improved understanding of the processes that drive these fluxes is important for climate projections, weather prediction, flood forecasting, water and soil resources management, agriculture, and water quality control. The different transport mechanisms and flow rates within the compartments result in complex patterns on different temporal and spatial scales that make predictions of the Terrestrial System challenging for scientists and policy makers. The Transregional Collaborative Research Centre 32 (TR32) was formed in 2007 to integrate monitoring with modeling and data assimilation in order to develop a holistic view of the Terrestrial System. TR32 is a long-term research program ...
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Monitoring and Modeling the Terrestrial System from Pores to Catchments: The Transregional Collaborative Research Center on Patterns in the Soil–Vegetation–Atmosphere System
Bulletin of the American Meteorological Society, 2015Co-Authors: Clemens Simmer, M Masbou, Wulf Amelung, Heye Bogena, Susanne Crewell, Bernd Diekkruger, Frank Ewert, Harriejan Hendricks Franssen, Insa Thiele-eich, J A HuismanAbstract:Abstract Most activities of humankind take place in the transition zone between four compartments of the Terrestrial System: the unconfined aquifer, including the unsaturated zone; surface water; vegetation; and atmosphere. The mass, momentum, and heat energy fluxes between these compartments drive their mutual state evolution. Improved understanding of the processes that drive these fluxes is important for climate projections, weather prediction, flood forecasting, water and soil resources management, agriculture, and water quality control. The different transport mechanisms and flow rates within the compartments result in complex patterns on different temporal and spatial scales that make predictions of the Terrestrial System challenging for scientists and policy makers. The Transregional Collaborative Research Centre 32 (TR32) was formed in 2007 to integrate monitoring with modeling and data assimilation in order to develop a holistic view of the Terrestrial System. TR32 is a long-term research program funded by the German national science foundation Deutsche Forschungsgemeinschaft (DFG), in order to focus and integrate research activities of several universities on an emerging scientific topic of high societal relevance. Aiming to bridge the gap between microscale soil pores and catchment-scale atmospheric variables, TR32 unites research groups from the German universities of Aachen, Bonn, and Cologne, and from the environmental and geoscience departments of Forschungszentrum Jülich GmbH. Here, we report about recent achievements in monitoring and modeling of the Terrestrial System, including the development of new observation techniques for the subsurface, the establishment of cross-scale, multicompartment modeling platforms from the pore to the catchment scale, and their use to investigate the propagation of patterns in the state and structure of the subsurface to the atmospheric boundary layer.
Harriejan Hendricks Franssen - One of the best experts on this subject based on the ideXlab platform.
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High-Resolution Virtual Catchment Simulations of the Subsurface- Land Surface-Atmosphere System
2016Co-Authors: Bernd Schalge, Insa Neuweiler, Jehan Rihani, Gabriele Baroni, Daniel Erdal, Gernot Geppert, Vincent Haefliger, Barbara Haese, Pablo Saavedra, Harriejan Hendricks FranssenAbstract:Abstract. Combining numerical models, which simulate water and energy fluxes in the subsurface-land surface-atmosphere System in a physically consistent way, becomes increasingly important to understand and study fluxes at compartmental boundaries and interdependencies of states across these boundaries. Complete state evolutions generated by such models, when run at highest possible resolutions while incorporating as many processes as attainable, may be regarded as a proxy of the real world – a virtual reality – which can be used to test hypotheses on functioning of the coupled Terrestrial System and may serve as source for virtual measurements to develop data-assimilation methods. Such simulation Systems, however, face severe problems caused by the vastly different scales of the processes acting in the compartments of the Terrestrial System. The present study is motivated by the development of cross-compartmental data-assimilation methods, which face the difficulty of data scarcity in the subsurface when applied to real data. With appropriate and realistic measurement operators, the virtual reality not only allows taking virtual observations in any part of the Terrestrial System at any density, thus overcoming data-scarcity problems of real-world applications, but also provides full information about true states and parameters aimed to be reconstructed from the measurements by data assimilation. In the present study, we have used the Terrestrial Systems Modeling Platform TerrSysMP, which couples the meteorological model COSMO, the land-surface model CLM, and the subsurface model ParFlow, to set up the virtual reality for a regional Terrestrial System roughly oriented at the Neckar catchment in southwest Germany. We find that the virtual reality is in many aspects quite close to real observations of the catchment concerning, e.g., atmospheric boundary-layer height, precipitation, and runoff. But also discrepancies become apparent both in the ability of such models to correctly simulate some processes – which still need improvement – and the realism of the results of some observation operators like the SMOS and SMAP sensors, when faced with model states. In a succeeding step, we will use the virtual reality to generate observations in all compartments of the System for coupled data assimilation. The data assimilation will rely on a coarsened and simplified version of the model System.
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monitoring and modeling the Terrestrial System from pores to catchments the transregional collaborative research center on patterns in the soil vegetation atmosphere System
Bulletin of the American Meteorological Society, 2015Co-Authors: Clemens Simmer, Insa Thieleeich, M Masbou, Wulf Amelung, Heye Bogena, Susanne Crewell, Bernd Diekkruger, Frank Ewert, Harriejan Hendricks Franssen, J A HuismanAbstract:AbstractMost activities of humankind take place in the transition zone between four compartments of the Terrestrial System: the unconfined aquifer, including the unsaturated zone; surface water; vegetation; and atmosphere. The mass, momentum, and heat energy fluxes between these compartments drive their mutual state evolution. Improved understanding of the processes that drive these fluxes is important for climate projections, weather prediction, flood forecasting, water and soil resources management, agriculture, and water quality control. The different transport mechanisms and flow rates within the compartments result in complex patterns on different temporal and spatial scales that make predictions of the Terrestrial System challenging for scientists and policy makers. The Transregional Collaborative Research Centre 32 (TR32) was formed in 2007 to integrate monitoring with modeling and data assimilation in order to develop a holistic view of the Terrestrial System. TR32 is a long-term research program ...
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Monitoring and Modeling the Terrestrial System from Pores to Catchments: The Transregional Collaborative Research Center on Patterns in the Soil–Vegetation–Atmosphere System
Bulletin of the American Meteorological Society, 2015Co-Authors: Clemens Simmer, M Masbou, Wulf Amelung, Heye Bogena, Susanne Crewell, Bernd Diekkruger, Frank Ewert, Harriejan Hendricks Franssen, Insa Thiele-eich, J A HuismanAbstract:Abstract Most activities of humankind take place in the transition zone between four compartments of the Terrestrial System: the unconfined aquifer, including the unsaturated zone; surface water; vegetation; and atmosphere. The mass, momentum, and heat energy fluxes between these compartments drive their mutual state evolution. Improved understanding of the processes that drive these fluxes is important for climate projections, weather prediction, flood forecasting, water and soil resources management, agriculture, and water quality control. The different transport mechanisms and flow rates within the compartments result in complex patterns on different temporal and spatial scales that make predictions of the Terrestrial System challenging for scientists and policy makers. The Transregional Collaborative Research Centre 32 (TR32) was formed in 2007 to integrate monitoring with modeling and data assimilation in order to develop a holistic view of the Terrestrial System. TR32 is a long-term research program funded by the German national science foundation Deutsche Forschungsgemeinschaft (DFG), in order to focus and integrate research activities of several universities on an emerging scientific topic of high societal relevance. Aiming to bridge the gap between microscale soil pores and catchment-scale atmospheric variables, TR32 unites research groups from the German universities of Aachen, Bonn, and Cologne, and from the environmental and geoscience departments of Forschungszentrum Jülich GmbH. Here, we report about recent achievements in monitoring and modeling of the Terrestrial System, including the development of new observation techniques for the subsurface, the establishment of cross-scale, multicompartment modeling platforms from the pore to the catchment scale, and their use to investigate the propagation of patterns in the state and structure of the subsurface to the atmospheric boundary layer.
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Data assimilation for improved predictions of integrated Terrestrial Systems
Advances in Water Resources, 2015Co-Authors: Harriejan Hendricks Franssen, Insa NeuweilerAbstract:Predicting states or fluxes in a Terrestrial System, such as, for example, a river discharge, groundwater recharge or air temperature is done with Terrestrial System models, which describe the processes in an approximate way. Terrestrial System model predictions are affected by uncertainty. Important sources of uncertainty are related to model forcings, initial conditions and boundary conditions, model parameters and the model itself. The relative importance of the different uncertainty sources varies according to the specific Terrestrial compartment for which the model is built. For example, for weather prediction with atmospheric models it is believed that a dominant source of uncertainty is the initial model condition [12]. For groundwater models on the other hand, a general assumption is that parameter uncertainty dominates the total model prediction uncertainty.Sequential data assimilation techniques allow improving model predictions and reducing their uncertainty by correcting the predictions with measurement data. This can be done on-line with real-time measurement data. It can also be done off-line by updating model predictions with time series of historical data. Off-line data assimilation is especially interesting for estimating parameters in combination with model states, or for a reanalysis of past states. The most applied sequential data assimilation techniques for Terrestrial System model predictions are the Ensemble Kalman Filter (EnKF) [8] and the Particle Filter (PF) [2]. EnKF provides an optimal solution for Gaussian distributed parameters, states and measurement data, whereas the PF is more flexible but computationally more expensive and provides in theory an optimal solution independent of the distribution typ
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Multivariate and Multiscale Data Assimilation in Terrestrial Systems: A Review
Sensors (Basel Switzerland), 2012Co-Authors: Carsten Montzka, Harriejan Hendricks Franssen, Valentijn R. N. Pauwels, Xujun Han, Harry VereeckenAbstract:More and more Terrestrial observational networks are being established to monitor climatic, hydrological and land-use changes in different regions of the World. In these networks, time series of states and fluxes are recorded in an automated manner, often with a high temporal resolution. These data are important for the understanding of water, energy, and/or matter fluxes, as well as their biological and physical drivers and interactions with and within the Terrestrial System. Similarly, the number and accuracy of variables, which can be observed by spaceborne sensors, are increasing. Data assimilation (DA) methods utilize these observations in Terrestrial models in order to increase process knowledge as well as to improve forecasts for the System being studied. The widely implemented automation in observing environmental states and fluxes makes an operational computation more and more feasible, and it opens the perspective of short-time forecasts of the state of Terrestrial Systems. In this paper, we review the state of the art with respect to DA focusing on the joint assimilation of observational data precedents from different spatial scales and different data types. An introduction is given to different DA methods, such as the Ensemble Kalman Filter (EnKF), Particle Filter (PF) and variational methods (3/4D-VAR). In this review, we distinguish between four major DA approaches: (1) univariate single-scale DA (UVSS), which is the approach used in the majority of published DA applications, (2) univariate multiscale DA (UVMS) referring to a methodology which acknowledges that at least some of the assimilated data are measured at a different scale than the computational grid scale, (3) multivariate single-scale DA (MVSS) dealing with the assimilation of at least two different data types, and (4) combined multivariate multiscale DA (MVMS). Finally, we conclude with a discussion on the advantages and disadvantages of the assimilation of multiple data types in a simulation model. Existing approaches can be used to simultaneously update several model states and model parameters if applicable. In other words, the basic principles for multivariate data assimilation are already available. We argue that a better understanding of the measurement errors for different observation types, improved estimates of observation bias and improved multiscale assimilation methods for data which scale nonlinearly is important to properly weight them in multiscale multivariate data assimilation. In this context, improved cross-validation of different data types, and increased ground truth verification of remote sensing products are required.
Clemens Simmer - One of the best experts on this subject based on the ideXlab platform.
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monitoring and modeling the Terrestrial System from pores to catchments the transregional collaborative research center on patterns in the soil vegetation atmosphere System
Bulletin of the American Meteorological Society, 2015Co-Authors: Clemens Simmer, Insa Thieleeich, M Masbou, Wulf Amelung, Heye Bogena, Susanne Crewell, Bernd Diekkruger, Frank Ewert, Harriejan Hendricks Franssen, J A HuismanAbstract:AbstractMost activities of humankind take place in the transition zone between four compartments of the Terrestrial System: the unconfined aquifer, including the unsaturated zone; surface water; vegetation; and atmosphere. The mass, momentum, and heat energy fluxes between these compartments drive their mutual state evolution. Improved understanding of the processes that drive these fluxes is important for climate projections, weather prediction, flood forecasting, water and soil resources management, agriculture, and water quality control. The different transport mechanisms and flow rates within the compartments result in complex patterns on different temporal and spatial scales that make predictions of the Terrestrial System challenging for scientists and policy makers. The Transregional Collaborative Research Centre 32 (TR32) was formed in 2007 to integrate monitoring with modeling and data assimilation in order to develop a holistic view of the Terrestrial System. TR32 is a long-term research program ...
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Monitoring and Modeling the Terrestrial System from Pores to Catchments: The Transregional Collaborative Research Center on Patterns in the Soil–Vegetation–Atmosphere System
Bulletin of the American Meteorological Society, 2015Co-Authors: Clemens Simmer, M Masbou, Wulf Amelung, Heye Bogena, Susanne Crewell, Bernd Diekkruger, Frank Ewert, Harriejan Hendricks Franssen, Insa Thiele-eich, J A HuismanAbstract:Abstract Most activities of humankind take place in the transition zone between four compartments of the Terrestrial System: the unconfined aquifer, including the unsaturated zone; surface water; vegetation; and atmosphere. The mass, momentum, and heat energy fluxes between these compartments drive their mutual state evolution. Improved understanding of the processes that drive these fluxes is important for climate projections, weather prediction, flood forecasting, water and soil resources management, agriculture, and water quality control. The different transport mechanisms and flow rates within the compartments result in complex patterns on different temporal and spatial scales that make predictions of the Terrestrial System challenging for scientists and policy makers. The Transregional Collaborative Research Centre 32 (TR32) was formed in 2007 to integrate monitoring with modeling and data assimilation in order to develop a holistic view of the Terrestrial System. TR32 is a long-term research program funded by the German national science foundation Deutsche Forschungsgemeinschaft (DFG), in order to focus and integrate research activities of several universities on an emerging scientific topic of high societal relevance. Aiming to bridge the gap between microscale soil pores and catchment-scale atmospheric variables, TR32 unites research groups from the German universities of Aachen, Bonn, and Cologne, and from the environmental and geoscience departments of Forschungszentrum Jülich GmbH. Here, we report about recent achievements in monitoring and modeling of the Terrestrial System, including the development of new observation techniques for the subsurface, the establishment of cross-scale, multicompartment modeling platforms from the pore to the catchment scale, and their use to investigate the propagation of patterns in the state and structure of the subsurface to the atmospheric boundary layer.
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Integrated simulations of mass and energy fluxes in the Terrestrial System: concepts and applications
2014Co-Authors: Stefan Kollet, Jessica Keune, Klaus Goergen, Christian Ohlwein, Anne Springer, Jürgen Kusche, Prabhakar Shrestha, Mauro Sulis, Clemens Simmer, Harry VereeckenAbstract:Remote sensing (airborne and satellite) in combination with in-situ measurements provide unprecedented observations across multiple space and time scales of the Terrestrial hydrologic, energy, and also biogeochemical cycles. These observations are useful in the quantification of mass fluxes within and between the major compartments of the Terrestrial System that are the subsurface, the land surface and the atmosphere. As a matter of fact, one may argue that our analyses and simulation capabilities are lacking behind our current and future observation capabilities, since multi-physics modeling platforms are missing, which are able to simulate the Terrestrial System at the required spatial and temporal resolutions over continents and the climate time scale. This is especially disconcerting, because, ultimately, the amalgamation of observations and simulations at the respective scales is the only viable option of arriving at useful predictions and uncertainty estimates of states and fluxes, which are urgently needed in the context of global change. In order to close this gap, a simulation approach is presented, which is based on coupling of physics-based modeling platforms from the deeper subsurface into the atmosphere closing the hydrologic and energy cycles in Terrestrial System models. The resulting integrated Terrestrials Systems Modeling Platform, TerrSysMP, is applied over regional watersheds and the European continent (Euro-CORDEX domain) in order to compare to a suite of in-situ measurements and remotely sensed observations, and understand the challenges and possibilities of the proposed simulation approach. We find that the memory effects of deeper groundwater dynamics pose a challenge in arriving at physically consistent initial conditions, which is also well-known in ocean modeling. The great potential lies in the ability to characterize all components of the hydrologic and energy cycle, which is not possible with more traditional simulation approaches, and, thus, synthesize and assimilate all available observations consistently.
Ramon Brasser - One of the best experts on this subject based on the ideXlab platform.
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constructing the secular architecture of the solar System ii the Terrestrial planets
Astronomy and Astrophysics, 2009Co-Authors: Ramon Brasser, Alessandro Morbidelli, Kleomenis Tsiganis, R S Gomes, Harold F LevisonAbstract:We investigate the dynamical evolution of the Terrestrial planets during the planetesimal-driven migration of the giant planets. A basic assumption of this work is that giant planet migration occurred after the completion of Terrestrial planet formation, such as in the models that link the former to the origin of the late heavy bombardment. The divergent migration of Jupiter and Saturn causes the g5 eigenfrequency to cross resonances of the form g5 = gk with k ranging from 1 to 4. Consequently these secular resonances cause large-amplitude responses in the eccentricities of the Terrestrial planets if the amplitude of the g5 mode in Jupiter is similar to the current one. We show that the resonances g5 = g4 and g5 = g3 do not pose a problem if Jupiter and Saturn have a fast approach and departure from their mutual 2:1 mean motion resonance. On the other hand, the resonance crossings g5 = g2 and g5 = g1 are more of a concern: they tend to yield a Terrestrial System incompatible with the current one, with amplitudes of the g1 and g2 modes that are too large. We offer two solutions to this problem. The first solution states that a secular resonance crossing can also damp the amplitude of a Fourier mode if the latter is large originally. We show that the probability of the g5 = g2 resonance damping a primordially excited g2 mode in the Earth and Venus is approximately 8%. Using the same mechanism to also ensure that the g5 = g1 resonance keeps the amplitude of the g1 mode in Mercury within 0.4 reduces the overall probability to approximately 5%. However, these numbers may change for different initial excitations and migration speeds of the giant planets. A second scenario involves a “jumping Jupiter” in which encounters between an ice giant and Jupiter, without ejection of the former, cause the latter to migrate away from Saturn much faster than if migration is driven solely by encounters with planetesimals. In this case, the g5 = g2 and g5 = g1 resonances can be jumped over, or occur very briefly. We show that, in this case, the Terrestrial System can have dynamical properties comparable to what is exhibited today. In the framework of the Nice model, we estimate that the probability that Jupiter had this kind of evolution is approximately 6%.
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Constructing the secular architecture of the solar System II: The Terrestrial planets
Astronomy and Astrophysics - A&A, 2009Co-Authors: Ramon Brasser, Rodney Gomes, Alessandro Morbidelli, Kleomenis Tsiganis, Harold LevisonAbstract:We investigate the dynamical evolution of the Terrestrial planets during the planetesimal-driven migration of the giant planets. A basic assumption of this work is that giant planet migration occurred after the completion of Terrestrial planet formation, such as in the models that link the former to the origin of the Late Heavy Bombardment. The divergent migration of Jupiter and Saturn causes the g5 eigenfrequency to cross resonances of the form g5=gk with k ranging from 1 to 4. Consequently these secular resonances cause large-amplitude responses in the eccentricities of the Terrestrial planets. We show that the resonances g5=g_4 and g5=g3 do not pose a problem if Jupiter and Saturn have a fast approach and departure from their mutual 2:1 mean motion resonance. On the other hand, the resonance crossings g5=g2 and g5=g1 are more of a concern as they tend to yield a Terrestrial System incompatible with the current one. We offer two solutions to this problem. The first uses the fact that a secular resonance crossing can also damp the amplitude of a Fourier mode if the latter is large originally. A second scenario involves a 'jumping Jupiter' in which encounters between an ice giant and Jupiter, without ejection of the former, cause the latter to migrate away from Saturn much faster than if migration is driven solely by encounters with planetesimals. In this case, the g5=g2 and g5=g1 resonances can be jumped over, or occur very briefly.
Wulf Amelung - One of the best experts on this subject based on the ideXlab platform.
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monitoring and modeling the Terrestrial System from pores to catchments the transregional collaborative research center on patterns in the soil vegetation atmosphere System
Bulletin of the American Meteorological Society, 2015Co-Authors: Clemens Simmer, Insa Thieleeich, M Masbou, Wulf Amelung, Heye Bogena, Susanne Crewell, Bernd Diekkruger, Frank Ewert, Harriejan Hendricks Franssen, J A HuismanAbstract:AbstractMost activities of humankind take place in the transition zone between four compartments of the Terrestrial System: the unconfined aquifer, including the unsaturated zone; surface water; vegetation; and atmosphere. The mass, momentum, and heat energy fluxes between these compartments drive their mutual state evolution. Improved understanding of the processes that drive these fluxes is important for climate projections, weather prediction, flood forecasting, water and soil resources management, agriculture, and water quality control. The different transport mechanisms and flow rates within the compartments result in complex patterns on different temporal and spatial scales that make predictions of the Terrestrial System challenging for scientists and policy makers. The Transregional Collaborative Research Centre 32 (TR32) was formed in 2007 to integrate monitoring with modeling and data assimilation in order to develop a holistic view of the Terrestrial System. TR32 is a long-term research program ...
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Monitoring and Modeling the Terrestrial System from Pores to Catchments: The Transregional Collaborative Research Center on Patterns in the Soil–Vegetation–Atmosphere System
Bulletin of the American Meteorological Society, 2015Co-Authors: Clemens Simmer, M Masbou, Wulf Amelung, Heye Bogena, Susanne Crewell, Bernd Diekkruger, Frank Ewert, Harriejan Hendricks Franssen, Insa Thiele-eich, J A HuismanAbstract:Abstract Most activities of humankind take place in the transition zone between four compartments of the Terrestrial System: the unconfined aquifer, including the unsaturated zone; surface water; vegetation; and atmosphere. The mass, momentum, and heat energy fluxes between these compartments drive their mutual state evolution. Improved understanding of the processes that drive these fluxes is important for climate projections, weather prediction, flood forecasting, water and soil resources management, agriculture, and water quality control. The different transport mechanisms and flow rates within the compartments result in complex patterns on different temporal and spatial scales that make predictions of the Terrestrial System challenging for scientists and policy makers. The Transregional Collaborative Research Centre 32 (TR32) was formed in 2007 to integrate monitoring with modeling and data assimilation in order to develop a holistic view of the Terrestrial System. TR32 is a long-term research program funded by the German national science foundation Deutsche Forschungsgemeinschaft (DFG), in order to focus and integrate research activities of several universities on an emerging scientific topic of high societal relevance. Aiming to bridge the gap between microscale soil pores and catchment-scale atmospheric variables, TR32 unites research groups from the German universities of Aachen, Bonn, and Cologne, and from the environmental and geoscience departments of Forschungszentrum Jülich GmbH. Here, we report about recent achievements in monitoring and modeling of the Terrestrial System, including the development of new observation techniques for the subsurface, the establishment of cross-scale, multicompartment modeling platforms from the pore to the catchment scale, and their use to investigate the propagation of patterns in the state and structure of the subsurface to the atmospheric boundary layer.
