Keynote Speaker: Dr. Daniela Vanella
Department of Agriculture, Food and Environment, University of Catania, More Infomation

Conveners: Daniel Rasche (GFZ), Laurent Longuevergne (Géosciences, Rennes), Ulrike Werban (UFZ, Leipzig), Nolwenn Lesparre (ITES, Strasbourg)

Abstract: Access to informative observation is a pre-requisite to understand how linkages between geological, biological and hydrological cycles defines the critical zone. This thin and highly heterogeneous layer of the Earth extends from the land surface, including vegetation and water bodies, through the pedosphere and the unsaturated zone to the groundwater. The challenges consist in obtaining adequate representations of landscape spatial heterogeneity to inform bottom-up modeling approaches, or to design and perform integrated measurements to meaningfully constrain top-down modeling approaches. Several data sources are rarely used or poorly exploited in critical zone studies. These include new types of data that are still under investigation, as well as traditional types of data (e.g. results of fieldwork investigations, maps of various characteristics of the landscape) that are seldom used to a full degree in larger scale studies for various reasons, such as incommensurability problems and inadequate models.

This session will focus on how data obtained from new observation techniques and from innovative analysis of existing data sources can be used to inform model design and process identification at larger scales. We solicit contributions related but not limited to:

(i) Innovative sensing and experimental techniques to advance understanding of the critical zone (e.g. wireless distributed sensing, cosmic-ray neutron sensing, hydrogeophysical methods, fiber optics, tracing methods, etc.). We also encourage submissions of works focusing on new instrumental techniques and developments with strong potential to widen points of views (microbiology, citizen science, …) and update approaches (energetic and teletransmission challenges, …)

(ii) Methods for the evaluation, visualization, and interpretation of monitoring and experimental data sets from multiple sources to maximize the information gained from critical zone observatories. Thus, we encourage submissions of works dealing with model-data fusion including new concepts for joint and coupled inversion.

(iii) Analysis of spatial and temporal patterns of critical zone properties and processes at different scales (e.g. source deconvolution for hot moments/hot spots identification)

(iv) Unusual and unexpected critical zone phenomena identified by measurements that seem to defy current understanding of the critical zone. Such phenomena could have been observed in the field or in the laboratory. Contributions focussing on the understanding of linked hydrological, geophysical properties and or geochemical processes are highly welcome.

Keynote Speaker: Prof. Kevin Bishop
Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, More Information

Conveners: Steffen Zacharias (UFZ, Leipzig), Thomas Pütz (FZ Jülich), Jérôme Gaillardet (IPGP, Paris)

Abstract: Climate change and anthropogenic activities affect the sustainability and resilience of our environment at different scales. In order to assess the impacts and their complexity on the different compartments of our environment, research activities need to be designed on spatial and temporal scales. State-of-the-art research must meet these challenges and conceptually pursue new, innovative paths and approaches that are integrative and designed as long-term investigations.  This session is dedicated to the observation of terrestrial surfaces over the long-term and addressing the different compartments or “spheres” (geo-hydro-atmo-bio and socio-economic). This session will present long-term observations of terrestrial study areas that cover the broad spectrum of topics from purely physical/chemical methods to socio-ecological approaches. Different scientific disciplines use their specific perspectives and observation strategies: observe compartments at different scales, monitor key leading parameters, use interactions between model and data, and the participation of stakeholders. In this session, we aim to compare the different perspectives, research approaches, and initiatives for an integrative approach to terrestrial ecosystem monitoring. We request contributions on scientific approaches and the design of observatories and observatory networks that observe the human environment and the pronounced changes that our habitat is undergoing in the Anthropocene. We would particularly appreciate contribution on the challenge of upscaling local observations to the continental ones.

Keynote Speaker: Dr. Anna Balenzano
Institute for Electromagnetic Sensing of the Environment, National Research Council of Italy, More Information

Conveners: Carsten Montzka (FZ Jülich), Jian Peng (UFZ, Leipzig), Manuela Grippa (GET, Toulouse), Saskia Foerster (GFZ, Potsdam)

Abstract: The soil-vegetation-atmosphere continuum is a highly dynamic zone exchanging heat, momentum, water and nutrients such as carbon and nitrogen. It plays a significant role in microclimate, crop productivity, and can even affect extreme weather phenomena such as heat waves or floods. Remote sensing can be used to understand related key land surface properties, patterns, and processes. In this session we invite contributions that employ remote sensing on various platforms to gain knowledge about the soil-vegetation-atmosphere continuum. The topics may include, but are not limited to:

• Retrieval and analysis of land surface parameters describing vegetation, hydrology, energy, and nutrient patterns.

• Investigation of fluxes and processes between different land surface compartments and feedbacks.

• Analysis of extreme events such as floods and droughts with support of remote sensing.

• Utilization of remote sensing data from various platforms (UAVs, airborne, spaceborne).

• Implementation of various sensor types such as multispectral, SAR, LiDAR, hyperspectral, and thermal as well as their combinations.

• Approaches to improve the spatial, spectral, radiometric, and temporal resolutions of remote sensing data for the analysis of land surface properties, patterns, and processes.

• Combination of remote sensing with in situ data or model systems to gain knowledge about unmonitored compartments.

• Implementation of different statistical, physical, and machine learning methods with remote sensing data to understand the soil-vegetation-atmosphere dynamics

Important note: Merged with topic 6

Keynote Speaker: Prof. Marie-Elodie Perga
Institute of Earth Surface Dynamics, University of Lausanne, More Information

Conveners: Fabien Arnaud (EDYTEM, Le Bourget du Lac), Cecile Blanchet (GFZ, Potsdam), Ingo Heinrich (DAI German Archaeological Institute, Berlin), Markus Schwab (GFZ, Potsdam)

Abstract: Critical zone processes and their driving mechanisms including climate forcing (temperature, precipitation) and human impacts (pollution, agriculture, erosion) operate on a variety of time and space scales. Instrumental measurements, however, are only available for a limited time period and thus cannot describe the entire potential variability. Proxy data from various biological and geological archives have demonstrated that climate variability and environmental changes can be reconstructed even on seasonal to millennial time scales. The quantitative exploitation of proxy data in terms of critical zone processes and related forcings can be improved by a better understanding of the signal transfer into the different geoarchives (e.g., lake sediments, tree rings, speleothems). Ideally, this is achieved by integrating modern observation/monitoring and recent well dated proxy records. This approach leads to a sophisticated proxy interpretation allowing for an advanced assessment of ongoing changes in the Critical Zone based on longer time perspectives.This session aims to address specific problems of research at the interface of instrumental and proxy time scales, for example, the different temporal resolutions of data. We want to encourage discussions among researchers from different disciplines trying to elaborate a long term integrative understanding of Critical Zone trajectories under the influence of different drivers. We especially welcome contributions on monitoring of proxy data formation to develop a retro-observation of Critical Zone processes: synchronization and dating of proxy data time series from different natural archives,  investigating the impacts and interactions of landscape forming and Critical Zone processes, combining high resolution archives with other data sources such as meteorological data, remote sensing data, historical information aiming at a comprehensive understanding of landscape evolution and Critical Zone processes, the use of landscape evolution models for hypothesis testing.

Keynote Speaker: Prof. Dörthe Tetzlaff
Ecohydrology and Biogeochemistry, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), More Information

Conveners: Camille Bouchez (Géosciences, Rennes), Jean Marçais (RiverLy, Lyon), Theresa Blume (GFZ)

Abstract: The way catchments dynamically retain and release water is crucial to inform ecosystem sustainability and water supply in the Anthropocene. Yet it is difficult to : i) quantify the different water storage compartments in the critical zone (vegetation, vadose zone, shallow or deep groundwater) and their associated water and substance turnover and ii) decipher how these reservoirs and associated fluxes will dynamically respond under changes in climate forcing and anthropic transformation (land use changes, intensive agriculture). This session invites advances focusing on the monitoring and modelling of water storage compartments at the catchment scale, particularly in intensively managed landscapes like agricultural or urban areas. We particularly invite contributions aiming at developing new ways of unravelling water storage dynamics through geophysical experiments (in-situ, remote investigation, time-lapse geophysics), multi-tracer developments and hydrologic characterization. We also encourage studies that outline fundamental descriptors of catchment water storages and their associated dynamics, through integrated hydrological modelling or storage selection function approaches. Advances seeking to reconcile active vs passive storage zones, the flux vs storage paradox, event vs old water are also highly welcome.

Keynote Speaker: Prof. Lutz Breuer
Institut für Landschaftsökologie und Ressourcenmanagement, Justus-Liebig-Universität Gießen, More Information

Conveners: Nicolas Brüggemann (FZ Jülich), Anke Hildebrandt (UFZ), Laure Gandois (LEFE, Toulouse)

Abstract: Climate, land-use change, and agricultural practices affect the biogeochemical cycling of water, carbon, and nutrients in terrestrial systems and influence their exchange with the atmosphere, surface waters and groundwater. As a key component of the critical zone, soil is at the heart of multiple interactions among climate, energy, water, nutrients, and biodiversity. At the interface between the atmosphere and vegetation, it plays an essential role in the transformation, dynamics, transfer, and storage of water, biogeochemical compounds and many types of anthropogenic pollutants. Too often, however, biogeochemical processes have been studied in only one (soil, including rhizosphere, plant roots, soil organisms, and soil solution) or two (vegetation and soil) components of the critical zone, in isolation from the atmosphere and hydrosphere. In addition, it is important to consider the processes on a broader spatial and temporal scale. In this regard, catchments and sub-catchments provide an invaluable tool for monitoring, understanding, and modeling coupled biogeochemical and hydrological processes, and for assessing water and elemental budgets. This session invites contributions that will enhance our understanding of the above processes. Emphasis should be placed not only on soluble elements and chemical weathering, but also on particulate matter, mechanical erosion, and gas exchange with the atmosphere. Contributions on biogeochemical cycles involving the various scales and compartments mentioned above are encouraged. A particular focus of the session should be on hydraulic connectivity within the watershed and on the role of wetlands, riparian zones, and hyporheic zones that link surface slope, groundwater, and channel systems and act as hotspots for biogeochemical cycling. Research contributions that use new methods and experimental techniques such as high-frequency or non-invasive sensors for long-term monitoring, as well as isotopic constraints, are particularly welcome.

Conveners: Ralf Kunkel (FZ Jülich), Jan Bumberger (UFZ), Ségolène Dega (UFZ, Leipzig), Isabelle Braud (RiverLy, Lyon)

Abstract: Together with the rapid development of sensor technologies and the implementation of environmental observation networks, a large number of data infrastructures, implementing FAIR (Findable Accessible, Interoperable and Reusable) principles, are being created to manage and provide access to observation data. These data are necessary to provide significant advances in Earth System understanding and modeling and to progress towards models with predictive power concerning the evolution of the Earth System. However, data collected in the observatories as well as their management are often very heterogeneous, rendering a better and easier integration of data from distributed infrastructures more complex. A better use of data strongly depends on the capabilities of dealing with fast growing multi-parameter data of heterogeneous sources and on effort employing data science methods, adapting new algorithms, developing data pipelines tailored to specific scientific needs and developing interoperability between heterogeneous systems to favor multidisciplinary research. The development of methods for the automatic real-time processing and integration of observation data in models is also required in many applications. Automated quality assessment/control pipelines, data discovery and exploration tools, standardized interfaces and vocabularies as well as data exchange strategies and security concepts are required to interconnecting distributed data infrastructures that meet FAIR and open science criteria. This session focuses on the specific requirements, techniques and solutions to process, provide and couple FAIR observation data from interoperable distributed infrastructures and to make observation data available for modelling and other interdisciplinary scientific needs.

Important note: Merged with topic 9;
New topic title: Extremes and the critical zone: Water and matter transport during floods and droughts, intermittent streams and processes at the groundwater-surface water interface

Keynote Speaker: Dr. Jantiene Baartman
Department of Environmental Sciences, Wageningen University and Research , More information

Conveners: Caroline le Bouteiller (ETNA, Grenoble), Claudia Schütze (UFZ, Leipzig), Andreas Musolff (UFZ, Leipzig), Agnès Rivière (Mines Paris - PSL, Paris)

Abstract: The quantity and quality of freshwater is threatened by anthropogenic impacts and climate change. Manifestations of climate change such as floods and droughts have strong impacts on landscape water partitioning, flowpaths and biogeochemical processing, and can exacerbate water quality problems caused by human inputs of nutrients and pollutants.

In this session, we will explore monitoring and modelling physical processes responsible for floods, droughts and focus on specific aspects of extreme hydrologic conditions: Erosion and sediment transport, intermittent streams, groundwater recharge, and the groundwater- surface water interface.

Erosion and sediment transport can cause natural hazards soil degradation and threaten water quality and ecosystem health. Stream intermittency is sensitive to hydrologic extremes, and recent drought years have shown to be increasingly common even in wet areas with relatively stable flow conditions. Evaluating the role of this drying and rewetting on stream- aquifer exchange, groundwater recharge, and turnover of nutrients and contaminants remains a challenge. The groundwater-surface water-interface, with its heterogeneous and dynamic hydrogeophysical functioning and biogeochemical reactivity, is likely to play a critical role.

Observatories such as OZCAR and TERENO can contribute to a better understanding of hydrological extremes in the critical zone. We therefore encourage contributions to this session that focus on monitoring, conduct field and laboratory experiments, or use data-driven or numerical models.

Promising approaches to monitoring include novel remote- sensing techniques, indirect methods to measure bedload fluxes, camera monitoring, geophysical surveys to better describe the subsurface, sediment and water fingerprinting, and better understanding of pathways through the catchment. From the modelling point of view, challenges include the development of parsimonious models, calibration/validation methods for multi-site, multi-scale, and multi-variable models, and coupling catchment-scale models that target water/suspended matter/reactive matter.

Important note: Merged with topic 8
New topic title: Extremes and the critical zone: Water and matter transport during floods and droughts, intermittent streams and processes at the groundwater-surface water interface

Keynote Speaker: Prof. Julian Klaus
Department of Geography, University of Bonn, More Information

Conveners: Andreas Musolff (UFZ, Leipzig), Agnès Rivière (Mines Paris - PSL, Paris), Caroline le Bouteiller (ETNA, Grenoble), Claudia Schütze (UFZ, Leipzig)

Abstract: The quantity and quality of freshwater is threatened by anthropogenic impacts and climate change. Manifestations of climate change such as floods and droughts have strong impacts on landscape water partitioning, flowpaths and biogeochemical processing, and can exacerbate water quality problems caused by human inputs of nutrients and pollutants.

In this session, we will explore monitoring and modelling physical processes responsible for floods, droughts and focus on specific aspects of extreme hydrologic conditions: Erosion and sediment transport, intermittent streams, groundwater recharge, and the groundwater- surface water interface.

Erosion and sediment transport can cause natural hazards soil degradation and threaten water quality and ecosystem health. Stream intermittency is sensitive to hydrologic extremes, and recent drought years have shown to be increasingly common even in wet areas with relatively stable flow conditions. Evaluating the role of this drying and rewetting on stream- aquifer exchange, groundwater recharge, and turnover of nutrients and contaminants remains a challenge. The groundwater-surface water-interface, with its heterogeneous and dynamic hydrogeophysical functioning and biogeochemical reactivity, is likely to play a critical role.

Observatories such as OZCAR and TERENO can contribute to a better understanding of hydrological extremes in the critical zone. We therefore encourage contributions to this session that focus on monitoring, conduct field and laboratory experiments, or use data-driven or numerical models.

Promising approaches to monitoring include novel remote- sensing techniques, indirect methods to measure bedload fluxes, camera monitoring, geophysical surveys to better describe the subsurface, sediment and water fingerprinting, and better understanding of pathways through the catchment. From the modelling point of view, challenges include the development of parsimonious models, calibration/validation methods for multi-site, multi-scale, and multi-variable models, and coupling catchment-scale models that target water/suspended matter/reactive matter.

Keynote Speaker: Dr. Cathy Hohenegger
Atmosphere in the Earth System, Max Planck Institute for Meteorology, More Information

Conveners: Agnès Ducharne (METIS, Paris), Harry Vereecken (FZ Jülich)

Abstract: Earth System models are key in understanding and assessing the impact of climate and land use on the functioning of the Earth system and its compartments. They allow making predictions and projections of the future evolution of the Earth system and the water and biogeochemical functioning of the land surface. They provide the scientific basis for designing mitigation and adaptation strategies to climate change. Still these models show considerable uncertainty in quantifying water and biogeochemical fluxes. This is caused by the uncertainty in both process descriptions, the parameterization of the land surface and uncertainty introduced by the still limited database for development, calibration and validation. In this session we seek contributions that aim at improving the description of the land surface and specifically the critical zone in Earth System models, with a specific focus on water and carbon.

Important note: Merged with topic 6

Keynote Speaker: Dr. Frank Hagedorn
Eidg. Forschungsanstalt WSL, More Information

Conveners: Ralf Kiese (KIT IMK-IFU Garmisch-Partenkirchen) and Florence Naaïm (INRAE Grenoble)

Abstract: Global change has triggered several transformations, such as alterations in climate, land productivity, water resources, natural hazards and atmospheric chemistry, with far reaching impacts on ecosystem functions and services. Finding solutions to climate and land cover change-driven impacts on our terrestrial environment is one of the most important scientific challenges of the 21st century, with interlinkages to the socio-economy. A global hot spot of climate change are mountain areas, such as the European Alps and preAlps, which have been exposed to more intense warming compared with the global average trend and to higher frequencies of extreme hydrological events, such as droughts and intense rainfall. This session will focus on meteorological, hydrological, biogeochemical and biodiversity interactions as well as feedback mechanisms in mountain critical zones such as:

• ecological and hydrological consequences of deglaciation, permafrost and snow cover change,

• alteration of weathering, erosion and avalanche processes operating under vegetation and/or climate change,

• alteration of water, energy and matter (CO2, other GHGs) exchange influencing ecosystem functions such as C and N storage, nutrient and water retention as well as productivity and biodiversity.

Conveners: Harrie-Jan Hendricks Franssen (FZ Jülich), Jean-Raynald de Dreuzy (Géosciences, Rennes)

Abstract: This session focuses on model-data fusion methods to increase our understanding of processes in the critical zone, or to achieve better predictions. Presentations could highlight the introduction of new model-data fusion methods in critical zone research, the use of new data types in model-data fusion, or the role of the process description or the simulation model. Applications are also of interest if a good verification of the model-data fusion approach could be achieved. Applications can be in different research areas related to the critical zone like soil science, hydrology, ecology, land surface modelling or terrestrial systems modelling. Besides more classical model-data fusion methods like inverse modelling and data assimilation, we are interested in machine learning approaches and applications, for applications on very different time scales ranging from short-term predictions via seasonal predictions to climate projections, as well as reanalyses. 

Important note: Merged with topic 6

Keynote Speaker: Dr. Daniella M Rempe
The University of Texas at Austin, Jackson School of Geosciences, More information

Conveners: Roland Bol (Forschungszentrum, Jülich), Céline Pisapia (IPGP, Paris), Damien Lemarchand (U. of Strasbourg), Susanne Liebner (GFZ)

Abstract: Interactions between mineral phases and living organisms affect in multifold ways the composition, organization, functioning, and evolution of the Critical Zone. This includes biological, chemical and physical weathering of the rock and soil formation, thus shaping pathways of element and water fluxes from deep aquifers and subsurface biosphere to the soil/plant system and development of the vegetation cover. This has broad impacts on surface and subsurface landscape shaping and atmospheric composition over geological time scales but also on quality of the soil and water resources at much shorter time scale. The aim of the session is to try to decipher the interactions between  the mineral/soil compartments and the structure and functioning of the ecosystems and their biota. We invite submissions from a wide range of spatial scales, e.g. from the mineral/molecule interface to the ecosystem scale, and using interdisciplinary approaches. Contributions may deal with the influence of biological processes and/or organic compounds on the weathering reactions, secondary mineral and soil formation processes including aggregation as well as on the formation of flow paths. We particularly welcome contributions on the developments of biotic or abiotic tracers, investigations on processes and rates of mineral/biota interactions as well as their consequences on biogeochemical and water cycles, and feedbacks between those processes and the structure and functioning of the Critical Zone, from the subsurface rocks to the soil and ecosystems.

Keynote Speaker: Prof. Nick van de Giesen
Faculty of Civil Engineering and Geosciences, TU Delft, More Information

Conveners: Harald Kunstmann (KIT IMK-IFU, Garmisch-Partenkirchen), Nanée Chahinian (HSM, Montpellier)

Abstract: The African continent is a particularly data scarce region and in parallel highly vulnerable to global change. The delineation of adaptation strategies requires an improved system understanding of the intertwined water-, energy- and biogeochemical cycles across the atmosphere, the land ecosystems and the subsurface. Their modification due to climate- and local land use change need to be assessed, as well as the impacts of societal changes on the critical zone. Scientifically sound options for improved climate resilience through smart land use, adaptation of infrastructure and housing, as well as water management need to be derived. This requires the development of suitable modelling approaches and the combination of model systems with terrestrial-, and satellite derived observations. There is the clear need for improved climate observation systems and land surface observations. Approaches need to consider particular challenges arising from the general data scarcity and poor technical infrastructure. Digital data rescue efforts need to be initiated. Strategies for the realisation of long term observations and -operation of infrastructure are mandatory. Joint international efforts for knowledge transfer and capacity building need to be enforced. We invite contributions addressing these multiple scientific-, technical- and societal challenges.