The American Geophysical Union will hold its annual fall meeting with the theme,"Shaping the Future of Science," on 7-11 December 2020 virtually with the possibilty of a regional gathering in San Francisco, CA. The registration fee will be around 50% less than the in-person rate and lower rates for graduate student and other groups.
Meeting website: https://www.agu.org/fall-meeting
Abstract: Soil organic matter (SOM) dynamics play a major role in determining nutrient supply and carbon (C) storage in ecosystems and in regulating atmospheric CO2 concentrations. Better constraints on SOM pools and fluxes are required to advance understanding and generate insight into how global change will influence soil C persistence and vulnerability. This session focuses on empirical, synthesis, and modeling studies addressing the stabilization and change of SOM including but not limited to: storage capacity, ages, and transit times of C in soils, mechanisms of stabilization/destabilization (including microbial interactions with mineral-OM associations and new methods for measuring and monitoring change), and ecosystem vulnerability. Studies that feature manipulation experiments (e.g., warming, precipitation, litter), geographically-distributed sites such as meta-analyses or gradients, and model-data integration are strongly encouraged. This session will highlight novel insights into soil carbon dynamics using ‘big data’ approaches. Applications of results including improvements to soil modeling, advances in land management decision support, and other outcomes are encouraged. Studies using cutting edge interdisciplinary approaches, from SOM molecular characterization to microbial -omics, near-surface geophysics, innovative soil sensors, and remote sensing observations are welcome.
Primary Convener: Avni Malhotra, Stanford University
Abstract: Catchment, critical zone, and ecosystem studies are foundational to hydrological, biogeochemical, and ecological process understanding. Studies and monitoring at sentinel sites provide context for understanding fundamental processes and detecting consequences of environmental change on ecosystems. Studies employ conventional techniques, or couple those approaches with novel and emerging technologies. Multi-site comparisons across a range of temporal and spatial scales synthesize individual place-based research into long-term and holistic understanding. We encourage contributions from catchment, critical zone, and ecosystem studies, particularly studies that are crucial to scientific discovery, managing resources, shaping policy and promoting societal well-being.
Primary Convener: Stephen D Sebestyen, USDA Forest Service
Abstract: Understanding of the physical-mechanisms underlying water, carbon, and nutrient cycling at the land-atmosphere interface rely on our perception of the climate-soil-vegetation interactions. For instance, land-use changes, ecosystem management, and climate variability alter the functionality of the Critical Zone, with potential implications for water resources, primary productivity, carbon sequestration, and land-atmosphere interaction. Despite the advances over the past decades, characterizing the effect of natural/human disturbances still necessitates a fundamental understanding of the interactions between hydrological, physical, and biogeochemical processes across spatiotemporal scales and biomes. Here, we solicit contributions aimed at building a mechanistic understanding of such interactions under different land-use changes, ecosystem management strategies, and climate forcings, through theoretical, modeling, experimental, and data analysis approaches. We welcome contributions that investigate fundamental and applied questions ranging from water and nutrient cycles to ecosystem productivity, water-carbon coupling to climate-soil-vegetation coevolution, plant water, and nutrient use efficiencies, ecological optimality, mineral-water interactions, and soil-carbon sequestration.
Primary Convener: Salvatore Calabrese, Texas A&M University
Abstract: Stable isotopes are powerful tools for studying the transport and transformation of water, carbon, and nutrients. Their use has enabled new understanding of the critical zone and the soil-plant-atmosphere continuum. Furthermore, new methodological and technological developments have not only facilitated using stable isotopes at finer scales, but also across larger domains. Thus, new opportunities and insights have emerged, supporting increasingly interdisciplinary perspectives on critical zone processes, across multiple scales. This session aims to bridge bio-hydro-geo-eco communities and address new understanding as well as the status quo on stable-isotope methods and applications in critical zone science. Studies that cross disciplinary boundaries and reveal new process understanding are especially welcome. This session also encourages presentations of opinions, perspectives, and syntheses that guide the critical zone stable isotope community.
Primary Convener: Scott T Allen, University of Utah
Abstract: Evapotranspiration (ET) is the largest loss to the annual continental water balance. It results from interactions between the reservoirs of the Critical Zone, coupling aquifers, soils, biosphere and atmosphere. It is then sensible to changes in temperature, moisture, CO2 concentration in the atmosphere, changes in land use and vegetation state in the biosphere, changes in water availability and water transfers above and below the surface even in deep aquifers. ET is also impacted through any water management policies like irrigation, dam and other impoundments. Small changes in ET represent huge water volumes that can impact massively recharge and river flows and thus our stores of freshwater. In this session we are specifically interested in contributions that study through observations and modelling, how surface and atmospheric changes will impact the continental water cycle through ET changes and then subsequent trajectories for water resources at the surface and in deep aquifers.
Primary Convener: Jean-Martial Cohard, University Joseph Fourier
Abstract: Stable, radioactive and radiogenic isotopes, trace element and noble gases are routinely utilized within the hydrologic sciences to quantify subsurface flow paths, sources, residence times and reactive processes. Residence times are an important metric reflecting the functioning of hydrological systems including water rock interaction, biogeochemical cycling, and water supply sustainability. Integrating novel tracers for residence times and reactive transport along subsurface flow paths into catchment hydrology leads to a better understanding of how watersheds function. The last decade has seen transformative advancements in analytical technology which necessitate revised experimental design, interpretation, analysis, and modeling approaches, and suggest the potential for new more accurate resolution of the structure of fluid transport and solute transformation across a broad range of scales. This session includes presentations offering new insights into the linkages between surface and subsurface hydrology, ecohydrology, environmental and resource sustainability, nutrient and contaminant hydrology stemming from novel isotopic tracers (e.g. tritium), trace elements and noble gases in field systems, laboratory experiments and numerical models.
Primary Convener: Ate Visser, Lawrence Livermore National Laboratory
Abstract: Bedrock landscapes span diverse climatic and tectonic settings, but they are understudied relative to their soil-mantled brethren. Bedrock landscape processes are predicated on rock material properties, fracture networks on all scales, and climatic conditions. All such factors influence weathering and the subsequent development of potentially predictable, diagnostic landscape forms. Yet fracture mechanics concepts such as subcritical cracking and the role of environment in time-dependent crack propagation are not fully integrated into surface process paradigms, despite the fact that much existing rock physics research is relevant to fracturing at Earth's surface. This session provides a venue for workers from diverse disciplines including Rock Physics, Surface Processes, Hazards and Critical Zone Science to explore and share emerging ideas at the interface between these communities. We seek presentations of field observations, experimental data, and numerical and physical modeling that may provide insights from the crack-tip to landscape scale regarding how bedrock landscapes evolve.
Primary Convener: Jill A Marshall, University of Arkansas
Abstract: Earth’s surface and shallow (<~100 m) subsurface environment, comprising air, water, biota, organic matter, and Earth materials, encompass the “critical zone”, the dynamic interface between the atmosphere, biosphere, hydrosphere, and lithosphere. While it is straightforward to characterize topography and the above-ground structure of the critical zone, limited direct observations make near-surface geophysics essential to mapping and monitoring below-ground critical zone architecture. Furthermore, their wide range of applicability in terms of scale of measurement (cm to km), makes these methods particularly versatile. In this session we request abstracts focusing on: 1) geophysical characterization/imaging of subsurface critical zone architecture; and/or 2) geophysical monitoring of critical zone processes/dynamics and their interaction with hydrological and biogeochemical cycles. Laboratory to field-based studies spanning from single-point to larger scale measurements (e.g., aerial surveys) with implications for monitoring of critical zone processes in the subsurface, are of particular interest. Studies linking scales of measurement also encouraged.
Primary Convener: Gregory Mount, Indiana University of Pennsylvania Main Campus
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