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Seminar Series

The FLUXNET Seminar Series is a monthly community event co-sponsored by FLUXNET Early Career Network, AmeriFlux AMP, and members of the AmeriFlux and FLUXNET communities. The theme of the events will alternate between community and science, and data/tech seminars.

Organizers: Christin Buechner, Housen Chu, Gavin McNicol, Lin Meng, Fred Otu-Larbi, Gilberto Pastorello, Will Richardson, and Gabriela Shirkey. For more information, contact us at: [email protected]

Also check out the AMP webinar series, with AmeriFlux content and tutorials.

FLUXNET-ECN Summer Series

For the summer months, the FLUXNET Early Career Network will lead a series of webinars focusing on the international FLUXNET network and its associated regional networks. If you’re new to FLUXNET and flux science, or are interested in participating within a regional network, these webinars will introduce you to the field and provide an opportunity for questions from some founding members.

Upcoming events

 

Past events

2023

  • Monday, October 23rd, 2023
    • Theme: Lessons Learned from Harnessing Eddy Covariance Networks to Evaluate OpenET Remote Sensing Models
    • Speaker: John Volk: John Volk has a PhD in Hydrology from the University of Nevada Reno and works as a research scientist and software engineer at the Desert Research Institute. He has broad interests in earth sciences including multi-scale hydrologic processes and modeling, climatology, and land surface energy balance. Dr. Volk works on assessing the accuracy of the remote sensing evapotranspiration (ET) data that has been operationally produced by the OpenET platform.
    • Description: To assess OpenET accuracy, direct comparisons with in situ ET data, primarily from eddy covariance systems, were conducted. Before comparison with remotely sensed ET, eddy covariance data requires an assessment of data quality including energy balance closure and corrections; flux footprint for each site were also developed. Uncertainty in eddy covariance data from energy balance closure error and other causes can be significant, and it is critical to take steps to reduce these uncertainties before using the data to evaluate remote sensing ET data. This talk will highlight key lessons from post-processing micrometeorological data, assessing energy balance closure error, and development of flux footprints for nearly 200 eddy covariance systems in the United States.
    • When: Monday, October 23rd, 9 am PST | 12 pm EST | 5 pm London | 2 am (Tuesday, October 24th) Tokyo
    • Webinar hosts: Karem Meza, Utah State University
    • Contact us: [email protected]
    • Recording: https://www.youtube.com/watch?v=4w0FkqfMYpY
  • Monday, October 23rd, 2023
    • Theme: Quantifying Uncertainties in Eddy Covariance-Derived Evapotranspiration Estimates: Insights from the GRAPEX Project
    • Speaker: Nicolas (Nico) Bambach: Nico has a PhD in Atmospheric Science from UC Davis and he works as an Assistant Project Scientist in the Department of Viticulture and Enology at the University of California-Davis. His research focuses on applying environmental biophysics methods to promote agroecosystem resiliency and sustainability. Nico has an extensive background in interdisciplinary research projects bridging Climate and Environmental Science, Management, and Policy. Nico’s current research focuses on developing novel lower-cost techniques to close the water and energy balance and advancing boundary layer micrometeorology fundamental theory to quantify ET uncertainty.
    • Description: Under ideal conditions, evapotranspiration (ET) fluxes derived through the eddy covariance (EC) technique are considered a direct measure of actual ET. Eddy covariance flux measurements provide estimates at a temporal frequency that allows examining sub-daily, daily, and seasonal scale processes and relationships between different surface fluxes. The Grape Remote Sensing Atmospheric Profile and Evapotranspiration eXperiment (GRAPEX) project has collected micrometeorological and biophysical data to ground-truth new remote sensing tools for fine-tuning vineyard irrigation management across numerous sites since 2013.
    • When: Monday, October 23rd, 9 am PST | 12 pm EST | 5 pm London | 2 am (Tuesday, October 24th) Tokyo
    • Webinar hosts: Karem Meza, Utah State University
    • Contact us: [email protected]
    • Recording: https://www.youtube.com/watch?v=4w0FkqfMYpY
  • Tuesday, August 29th, 2023
    • Theme: Can a Simple Ecosystem CO2 Flux Model Help Us Understand Complex Urban Background CO2 Conditions for Indianapolis, IN?
    • Speaker: Samantha Murphy: Sam is a PhD student working with Dr. Kenneth Davis and Dr. Natasha Miles in the Department of Meteorology and Atmospheric Science at Penn State. Her research is a part of the Indianapolis Flux Experiment (INFLUX). Broadly, Sam’s research interests include land-atmosphere interactions, urban greenhouse gas emissions, carbon cycling, and boundary layer meteorology.
    • Description: We evaluated the ability of a simple ecosystem CO2 flux model, the Vegetation Photosynthesis and Respiration Model (VPRM), to capture the complex CO2 background conditions previously observed in Indianapolis using the Indianapolis Flux Experiment (INFLUX) network. Using simulated biogenic CO2 fluxes from VPRM in conjunction with mole fraction tower influence functions, we estimated CO2 enhancements for background towers in the INFLUX network. We assessed the model’s ability to represent observed agricultural CO2 fluxes on average during the growing season and observed afternoon average CO2 enhancements at daily, monthly, and seasonal time scales. The goal of this study is to assess VPRM’s ability to represent complex CO2 background conditions surrounding Indianapolis, and therefore, to assess VPRM’s suitability for representing biological CO2 fluxes in urban inversions.
    • When: Tuesday, August 29th at 2:00 pm EST | 11:00 am PT
    • Webinar hosts:Helen Kenion, Penn State University
    • Contact us: [email protected]
    • Recording: https://www.youtube.com/watch?v=ys_sZmzbF2w
  • Tuesday, August 29th, 2023
    • Theme: What is the impact of turfgrass on urban carbon dioxide fluxes?
    • Speaker: Jason Horne:  Jason is a Ph.D. student at Penn State’s Department of Meteorology and Atmospheric Science. He works with Dr. Ken Davis and Dr. Ying Pan, conducting research under Baltimore Social-Environmental Collaborative (BSEC) IFL, The Indianapolis Flux Experiment (INFLUX), and the Susquehanna Shale Hills Critical Zone Observatory. His current research focuses are micrometeorology, surface layer turbulence, microclimate modeling, biometeorology, and urban ecology.
    • Description: Climate mitigations require the quantification of urban greenhouse gas (GHG) emissions. Urban systems mix anthropogenic and biogenic GHG fluxes. Disaggregation of these fluxes is necessary to understand urban systems. One vegetative community common in these urban environments is turfgrass. Turfgrass flux towers in Indianapolis show a photosynthetic drawdown in the winter when vegetation is commonly assumed to be dormant. We use data from these towers to create a new turfgrass Plant Functional Type (PFT) parameter set for the Vegetation Photosynthesis and Respiration Model (VPRM). The new turfgrass PFT enables VPRM to simulate photosynthetic activity during winter. Using these results, we explore daily and seasonal variability in turfgrass fluxes and their impact, integrated across the city, on total urban carbon dioxide (CO2) fluxes. This study illustrates the importance of representing turfgrass as a unique PFT when quantifying urban GHG fluxes.
    • When: Tuesday, August 29th at 2:00 pm EST | 11:00 am PT
    • Webinar hosts:Helen Kenion, Penn State University
    • Contact us: [email protected]
    • Recording: https://www.youtube.com/watch?v=ys_sZmzbF2w
  • Monday, March 6th, 2023
    • Theme:
    • Speaker: Oliver Sonnentag: Dr. Sonnentag is Associate Professor and Canada Research Chair in “Atmospheric Biogeosciences in High Latitudes” at the Université de Montréal. Sonnentag is interested in understanding changes in surface-atmosphere interactions across Arctic-boreal regions in response to changing climate and permafrost conditions. His main focus is on using eddy covariance and chamber techniques along a 2000-km transect of micrometeorological towers across northwestern Canada. The transects spans from central Saskatchewan, across the Taiga Plains ecoregion of the Northwest Territories, to the forest-tundra ecotone near the Beaufort Sea.
    • Description: Scotty Creek 2.0: Understanding interactions between wildfire and permafrost thaw using “nested” eddy covariance measurements. “Nested” eddy covariance measurements at Scotty Creek, a boreal peatland complex near the southern limit of permafrost in the Taiga Plains ecoregion, have provided important insights in how rapid permafrost thaw and associated land cover changes affect surface-atmosphere interactions. In October 2022, a late-season wildfire destroyed the Scotty Creek Research Station and most of the flux measurement infrastructure. Building on almost a decade of “nested” eddy covariance measurements at Scotty Creek, this event provides a unique opportunity to understand interactions between wildfire and permafrost thaw. In this presentation I will describe efforts to rebuild Scotty Creek in 2023 through the close collaboration of the scientific community and the Łı́ı́dlı̨́ı̨́ Kų́ę́ First Nation in Fort Simpson, NT.
    • Speaker: Kyle Arndt: Dr. Arndt is a research scientist at the Woodwell Climate Research Center in Falmouth Massachusetts, USA currently working on installing eddy flux sites in the least represented areas of the Arctic-boreal zone. His postdoctoral work at the University of New Hampshire focused on understanding the impact of grazing techniques on soil carbon using data from organic dairy farms and the DeNitrification and DeComposition (DNDC) model and his PhD work at San Diego State University and UC Davis researched seasonal impacts of climate change on greenhouse gas exchange from Arctic tundra ecosystems using eddy covariance and remote sensing.
    • Description: Strategic expansion of the Arctic-Boreal carbon flux network. Permafrost stores vast amounts of carbon, twice as much as the atmosphere. Warming is occurring at a rate three to four times the global average in Arctic-boreal ecosystems putting this carbon at risk of being released to the atmosphere in the form of carbon dioxide and/or methane exacerbating global climate warming. However, gaps in carbon flux data limit our ability to understand, upscale, model, and project carbon fluxes, which in turn limit our ability to set accurate emissions reduction targets to stay within globally agreed upon warming thresholds. To address this, we are strategically expanding the informal Arctic-boreal carbon flux network through the installation of ~10 new eddy covariance sites and supporting expanded measurements at existing sites (increasing winter and CH4 coverage). To guide site selection, we are using a representativeness analysis of the current eddy covariance network, determining the Euclidean distance in environmental data space using key carbon flux drivers at a 1 km2 spatial resolution across the Arctic-boreal region (Pallandt et al., 2022). Analyses show a lack of representation in the high Arctic, Siberia, and Eastern Canada, and representation is substantially lower when considering only sites with year-round measurement or that measure CH4. Work has begun including a re-installation in Churchill, MB, and upgrades for year-round and additional instrumentation for 4 towers in Alberta and the Northwest Territories, Canada and a site in Iqaluit, Nunavut, Canada.
    • When: Monday, March 6th, 9 am PST | 12 pm EST | 5 pm London | 2 am (Tuesday, March 7th) Tokyo
    • Webinar hosts: Theresia Yazbeck and Youmi Oh
    • Contact us: [email protected]
    • Recording: https://www.youtube.com/watch?v=AFRJ843g0CA

2022

  • Tuesday, October 25th, 2022
    • Theme: R package series: post-processing of eddy covariance flux data with REddyProc
    • Speakers: Thomas Wutzler and Tarek El-Madany, Max Planck Institute for Biogeochemistry
    • Description: REddyProc is toolset for the subsequent post-processing for half-hourly quality-checked fluxes. This workshop by Dr. Thomas Wutzler, the package author, consists of two parts: (1) An overview introduction about the main features of the REddyProc package. This overview can also help people using the REddyProc web service without any knowledge of R; and, (2) A hands-on session with prepared exercises in R, with assistance from Tarek El-Madany. Downloading and installation of the following softwares and packages in advance are recommended. There are: (i) R and RStudio; (ii) REddyProc (https://github.com/bgctw/REddyProc), and, (iii) exercise at (https://raw.githubusercontent.com/bgctw/EGU19EddyCourse/master/HandsOn/DEGebExample.Rmd). More information about the REddyProc homepage: https://www.bgc-jena.mpg.de/bgi/index.php/Services/REddyProcWeb and the paper: Citation: Wutzler T, Lucas-Moffat A, Migliavacca M, Knauer J, Sickel K, Sigut, Menzer O & Reichstein M (2018), Basic and extensible post-processing of eddy covariance flux data with REddyProc. Biogeosciences, Copernicus, 15, doi:10.5194/bg-15-5015-2018
    • When: Tuesday, October 25th, 8am PDT | 11am EDT | 5pm CEST
    • Webinar hosts: Xiangmin Sun, University of Illinois at Urbana-Champaign, and Jacob Nelson, Max Planck Institute for Biogeochemistry
    • Contact us: [email protected]
    • Recording: https://youtu.be/-b0vc4u8kls
  • Monday, July 18th, 2022
    • Theme: Regional Spotlight on Early Career Research in Asian Networks
    • Speaker: Chandra Shekhar Deshmukh, PhD, who currently works at the APRIL Group Indonesia. He leads a long-term monitoring to quantify net ecosystem exchanges of carbon dioxide, methane, and water vapor using the eddy covariance (EC) technique over four different land-uses (Acacia crassicarpa plantation forestry on peat, degraded peatland, intact peat swamp forest and Eucalyptus plantation on mineral soil) in Riau, Sumatra, Indonesia. His area of interest is understanding impact of large-scale land use change on greenhouse gas balances. He obtained his PhD (Biogeochemistry – Atmospheric Science) from the Université Toulouse III Paul Sabatier, Toulouse, France. In his presentation, “Quantifying Greenhouse Gas Footprints of Various Land Uses in Tropical Peatland in Indonesia” he will discuss the importance of the conservation, restoration, and improved management of tropical peatlands to address the climate crisis. Notably, existing estimates of greenhouse gas emissions and removals from tropical peatlands remain debated with large observed variability and resulting uncertainty due to limited measurements. Actual magnitude of greenhouse gas emissions and removals are urgently required to adequately estimate their global climate footprints and implement viable and verifiable nature-based climate solutions projects. His research involves four eddy covariance flux towers to measure net ecosystem exchanges of CO2, CH4 and water vapor over different land-uses in Sumatra, Indonesia.
    • Speaker: Jingyan Chen, who is a graduate student at the Institute of Botany, Chinese Academy of Sciences. Her presentation, “Energy budget over grasslands on the Mongolian Plateau” demonstrates how her team uses eddy covariance, vegetation and meteorological measurements at four dominant ecosystems on the Mongolian Plateau to quantify the changes in energy fluxes. Quantifying the magnitude of effects on energy budgets due to vegetation dynamics and atmospheric feedback is a great need. In her talk, she will discuss the responses of ecosystem energy partitioning to the interactions among microclimate and vegetation; as well as the changes of ecosystem energy partitioning that feeds back to vegetation and microclimate.
    • Speaker: Qingsong Zhu, who is a Masters Student in the College of Global Change and Earth System Science at Beijing Normal University. In his presentation “Chronosequent Changes in Albedo-Induced Global Warming Potential (GWPΔα) after Disturbance in Global Temperate Forests” he shares how FLUXNET data forest disturbances such as wildfires and harvesting result in very different canopies that carry reduced or elevated albedo, respectively. Moreso, the consequent global warming potential due to these changes in albedo (GWPΔα) is not known. In this work, his team used a dataset from 107 eddy covariance (EC) forest sites in the temperate regions, and evaluated the changes in GWPΔα with stand age by forest type and disturbance type.
    • When: Monday, July 18th, 6pm PDT | 9pm EDT | 2am (Tue, Jul 19th) London | 10am (Tue, Jul 19th) Tokyo
    • Webinar host: Gabriela Shirkey, Michigan State University
    • Contact us: [email protected]
    • Recording: https://youtu.be/nx_OXl4H9Fs
  • Friday, April 22nd, 2022
    • Speaker: Gabriela Posse, Instituto Nacional de Tecnología Agropecuaria (INTA), Argentina
    • Title: CO2 fluxes in agroecosystems of Argentina
    • Description: In Argentina, agricultural production is very relevant, since agriculture contributes around 60% of the total exports. In addition, INTA is a public institution whose objectives include conducting and centralizing research on agricultural technology and rural development. With the aim of characterizing the functioning of our main agroecosystems, we use the Eddy Covariance technique among other methods. In this way we want to determine if they function as a carbon source or sink. We also work on understanding how these dynamics are affected by the meteorological conditions and the anthropic management in these systems. We initially compared these dynamics in a natural dry forest, in a commercial afforestation and in agriculture paddocks. We are currently focused on comparing the dynamics on two very close sites: one in an agricultural site (where we started the measurements in 2012) vs. other on a pasture with cattle grazing (since 2018). Although the agricultural site seems to behave as a carbon source (taking into account the carbon exported on harvest), a model generated for the region using satellite data and grain yield information shows that, on average, the agricultural sites have a net balance of in favor of carbon accumulation in the soil.
    • Speaker Bio: Gabriela Posse has a Degree in Biological Sciences and a Ph.D. from the University of Buenos Aires, with an orientation in Ecology. She has been working at the Instituto Nacional de Tecnología Agropecuaria (INTA) since 2001 as a Researcher in the Remote Sensing area of ​​the Climate and Water Institute. Her areas of interest are related to the impact of agricultural activities on the environment, meteorological conditions on vegetation dynamics, carbon balances in the soil, fragmentation of environments, and effects of global change. She coordinated several projects to monitor greenhouse gas emissions resulting from agricultural activities.
    • Speaker: Hinsby Cadillo–Quiroz, Arizona State University
    • Title: Methane fluxes in Amazon peatlands: addressing their many unknowns through collaborations
    • Description: Peatlands in the Amazon were unknown to the scientific world a short time ago, they were rare anecdotal accounts that, however, overlapped with regions estimated with highest methane emission in the world. The discovery of large swaths of land (over 175,000 km2) holding diverse peatlands in the Amazon, have shown that peatlands develop under various geomorphic, vegetation, geochemistry and soil conditions. Little is known about the magnitude and dynamics of greenhouse gasses (GHG), particularly methane, and even less about their controls. In this presentation, I will focus on results from different projects assessing the connections of microbial processes, geochemistry, carbon stocks and methane fluxes in Amazon peatlands. These results are the fruit of collaborative efforts involving geochemistry, microbial, and forestry evaluations in connection with field explorations and multi-institutional support. Results show that methane emissions are highly variable across sites in a manner related to site geochemistry as a predictor of “order of magnitude” emissions and microbial make up. Hydrology is the stronger predictor of seasonal variation. The role of primary productivity, however, is more complex than expected for soil flux. The role of stems as conduct for methane emission is significantly high showing one of the highest changes in values of stem emission detected on wetlands from low rain to flood seasons in forested peatlands. Further collaborative monitoring is badly needed in the region.
    • Speaker Bio: Hinsby Cadillo–Quiroz is a microbial ecologist and enthusiast of understanding GHG fluxes in various ecosystems. He has a PhD in Microbiology with a minor in Ecology from Cornell University. He and his research team investigate whether microbe-mediated organismal and environmental interactions drive ecosystem processes, particularly carbon cycling. His team is also examining how the environment, in turn, affects the evolution of microorganisms. With significant focus on methane-producing Archaea, Hinsby has studied northern peatlands, deserts and desert crusts, marine aggregates, anoxic bioreactors, landfills, natural and artificial wetlands, lakes and ponds, and over the last few years Amazon peatlands. His current work in the Amazon includes collaborative efforts to understand forest dynamics at plot scale, hydrology and effects on geochemistry, microbial distribution and community dynamics, metagenomics, as well intensive monitoring of GHG fluxes from soils and vegetation.
    • When: Friday, April 22nd, 9am PDT | 12pm EST | 5pm London | 1am (Sat, Apr 23rd) Tokyo
    • Webinar host: André Santos, Federal University of Paraná, Brazil
    • Contact us: [email protected]
    • Recording: https://youtu.be/xO32030XTvk
  • Friday, March 11th, 2022
    • Speaker: Alana Ayasse, Carbon Mapper
    • Title: Careers in non-profit organizations with Alana Ayasse from Carbon Mapper [slides]
    • Description: In this webinar we will hear from Alana Ayasse from Carbon Mapper on careers in non-profit organizations, and what early careers need to know if considering joining this field.
    • Speaker Bio: Alana Ayasse is a Research Scientist for Carbon Mapper. Alana’s current research interests include understanding the role of satellites in a global carbon monitoring system and using airborne remote sensing data to further understand trends in methane and CO2 emissions. She has worked extensively with Imaging spectrometers (hyperspectral) and specializes in applying imaging spectrometers to map greenhouse gases. She received her M.A. in Geography from UCLA and Ph.D. in Geography from the University of California, Santa Barbara.
    • Institution: Carbon Mapper, Inc., is a non-profit (501c3) entity with a mission to deliver and guide the adoption of digital public goods that facilitate timely action to mitigate human impacts to Earth’s climate and ecosystems. Carbon Mapper recognizes there is an urgent need for a wide range of actions to accelerate methane (CH4) and carbon dioxide (CO2) mitigation. Barriers to action include high costs for methane leak detection, gaps in self-reported CO2 data, incomplete observations of priority regions at scales relevant for decision making, and lack of data accessibility and transparency. Through advanced satellite systems, Carbon Mapper hopes to provide data to erase these barriers. Currently, our airborne pilot projects are demonstrating the potential for an operational satellite data service that can help accelerate greenhouse gas mitigation. In this talk I will introduce Carbon Mapper and share results from ongoing airborne pilot projects.
    • When: Friday, March 11th, 9am PST | 12pm EST | 5pm London | 2am (Sat, Mar 12th) Tokyo
    • Webinar host: Theresia Yazbeck, The Ohio State University
    • Contact us: [email protected]
    • See recording: https://youtu.be/Ad-7c00mGc0

2021

  • Friday, November 5th, 2021
    • Speaker: Nelson Luís Dias, Federal University of Paraná, Brazil
    • Title: The importance of theoretical tools as guidance for flux measurements in the field [slides]
    • Description: The reliable measurement of surface fluxes in the field depends strongly on theoretical assumptions on the behavior of the underlying dynamical equations for turbulent flow. However, many of these assumptions are hard to verify and are often violated in practice. In spite of the significant challenge that this represents, the best (perhaps the only) hope of improving our understanding of surface-atmosphere exchanges lies in better understanding various terms of the averaged Navier-Stokes equations. In this talk I will give a few examples of this approach..
    • Speaker Bio: Nelson Luís Dias is a professor at the Environmental Engineering of the Federal University of Paraná, Brazil. He holds a B.Sc and an M.Sc in Civil Engineering from the Federal University of Rio de Janeiro, and a PhD from Cornell University. His research interests include Boundary-Layer Meteorology, Hydrology, and Numerical and Analytical Methods in Fluid Mechanics. He has done research in scalar similarity/dissimilarity in the atmosphere and surrogate systems such as Bénard-Rayleigh convection; lake evaporation and watershed evapotranspiration; analytical solutions for the Boussinesq groundwater equation; greenhouse emissions from lakes; radiation interaction with turbulence and longwave radiation models; unmanned atmospheric vehicles for probing the atmospheric boundary layer; and turbulence in the roughness sublayer, among others (https://nldias.github.io).
    • Speaker: Livia S. Freire, University of São Paulo, Brazil
    • Title: The study of atmospheric turbulent transport combining high-frequency measurements and numerical simulation [slides]
    • Description: A variety of environmental and human activities, including agriculture, ecology, meteorology, air quality and health, are impacted by the fate of gases and particles in the atmosphere. To predict their behavior, it is necessary to characterize the turbulent flow present in the atmospheric boundary layer, the lowest part of the atmosphere. Due to its complex nature, the study of turbulence relies heavily on the use of numerical simulations combined with the analysis of experimental data. For atmospheric flow, the use of high-frequency field measurements and the Large Eddy Simulation (LES) numerical tool has provided important insights on the transport of matter and energy. A recent example is the investigation regarding the impact of topography in the flow field of the Amazon rainforest. Therefore, advances in numerical tools and high-frequency field sensors are an important research area in the environmental and atmospheric sciences.
    • Speaker Bio: Livia Freire is a researcher at the University of São Paulo, Brazil, where she has been working on improving the understanding and modeling tools of atmospheric turbulence and boundary-layer meteorology. Her interests range from theoretical and numerical studies of turbulence to field data measurement and analysis, with emphasis in canopy flows and particle transport. Examples of recent studies include the investigation of flow properties (such as the critical flux Richardson number and the impact of topography on turbulence) in the Amazon rainforest using observational data, and the development of a new wall model for Large-Eddy Simulation of the atmospheric boundary layer to improve near-wall turbulent transport estimates. (https://freirelivia.gitlab.io/).
    • When: Friday, November 5th, 9am PDT | 12pm EDT | 5pm London | 2am (Sat, Nov 6th) Tokyo
    • Webinar host: André Santos, Federal University of Paraná, Brazil
    • Contact us: [email protected]
    • See recording: https://youtu.be/Naib4b8yrIA
  • Friday, March 5th, 2021
    • Speaker: Lianhong Gu, Oak Ridge National Laboratory
    • Title: The light reactions of photosynthesis and the grand hypothesis of eddy covariance energy imbalance
    • Description: Photosynthesis starts with the excitation of chlorophyll molecules by light. The excitation is then funneled to the reaction centers of photosystems where the energy of excitation is converted to charge separation and electron transport via a chain of redox reactions. The electron transport causes the buildup of protons in the lumen and the formation of electric field across the thylakoid membrane with the positive side in the lumen and the negative side in the stroma. This electric field provides the proton motive force (PMF) that drives the synthesis of high-energy molecule ATP across the membrane. At the end of the electron transport chain, the electrons reduce the lower energy molecule NADP+ to form the higher energy molecule NADPH. ATP and NADPH power the Calvin Cycle to produce sugar which stores some of the initially absorbed light energy in chemical bonds to support essentially all life on Earth. The light energy initially harvested by chlorophyll molecules is much higher than the chemical bond energy eventually stored in sugar because the processes of the formation of PMF and the production of ATP and NADPH also require energy. However, the difference between the light energy initially harvested and the chemical bond energy eventually stored does not appear as heat immediately to be detectable by a heat sensor such as eddy covariance. This is because it takes time for the proton motive force to dissipate and the ATP and NADPH to be consumed. At high light, the PMF may be stronger and the rates of production of ATP and NADPH may be higher than what are needed by the Calvin Cycle. Conversely, at low light, the PMF and the production rates of ATP and NADPH that can be supported by the available light may not be able to satisfy the demand of the Calvin Cycle. Therefore, the oversupply of PMF, ATP and NADPH at high light may compensate the shortage at low light. This compensation cannot be detected as sensible heat in the energy budget equations. I hypothesize that this is the reason why the eddy covariance system cannot close the energy budget. Technological and theoretical developments needed to test this hypothesis are now in place. This hypothesis leads to several predictions that can be experimentally or observationally checked for its falsification or confirmation.
    • Speaker Bio: Lianhong Gu is a Distinguished Research Staff Scientist in the Ecosystem Processes Group, Environmental Sciences Division, Oak Ridge National Laboratory. He conducts research in photosynthesis and ecosystem science with observational, theoretical, and experimental approaches. He is the inventor of the licensed technology Fluorescence Auto-Measurement Equipment (FAME), the software Integrated Measurement And Control System for SIF (IMACSS), and the community online tool leafweb (https://leafweb.org/).
    • Speaker: Jingfeng Xiao, University of New Hampshire
    • Title: Assessing drought impacts on terrestrial photosynthesis with satellite data from OCO-2 and SMAP
    • Description: Solar-induced chlorophyll fluorescence (SIF) measured from space (e.g., the Orbiting Carbon Observatory-2 or OCO-2) and both soil moisture and gross primary production (GPP) estimates from the Soil Moisture Active Passive (SMAP) provide new opportunities for understanding the responses terrestrial photosynthesis to water stress over large regions. In this presentation, we will explore the impacts of drought on photosynthesis using SIF (mainly from OCO-2 and partly from GOME-2), SMAP, and flux data.
    • Speaker Bio: Jingfeng Xiao is a global ecologist whose research is motivated by the compelling need to understand the impacts of climate change and human activities on the Earth’s biosphere and the feedbacks to the climate. He has never established or maintained any flux site but uses flux measurements for almost every project. With expertise in remote sensing and modeling, he has been upscaling AmeriFlux/FLUXNET data to the continental and global scales since 2007 and has also been heavily involved in synthesis and model improvement efforts. More recently, he has been studying carbon/water cycling and high-frequency Earth surface processes using observations from new polar-orbiting satellites (e.g., OCO-2, TROPOMI), International Space Station (e.g., ECOSTRESS, OCO-3), and geostationary satellites in combination with flux measurements.
    • When: Friday, March 5th, 9am PST | 12pm EST | 5pm London | 2am (Sat, Mar 6th) Tokyo
    • Webinar host: Lin Meng, Lawrence Berkeley National Laboratory
    • Contact us: [email protected]
    • See recording: https://youtu.be/hlhClCFpooo
  • Friday, January 29th, 2021
    • Speaker: Gil Bohrer, The Ohio State University
    • Title: The tree-hydrodynamic revolution – how stomata regulation moved from the soil to the trees
    • Description: The tree hydrodynamic hypothesis assumes that stomata regulation is driven by the dynamic balance of water content within the active xylem. This is a very different view of the classical stomata regulation approach, which is present in almost every model – linking stomata conductance to soil water availability through a wilting curve. Decade-long tree hydraulic observations in our forest flux sites in Michigan showed the importance of species-specific hydraulic strategy for the resulting diurnal patterns of transpiration and response to water shortage.
    • Speaker Bio: Gil Bohrer is one of the Ameriflux Core Flux Site PIs (US-UMB site cluster in Michigan). He studies greenhouse gas fluxes from forests and wetlands and runs several long-term flux sites (Michigan forest, Ohio wetland), and short temp flux tower deployments at industrial, agricultural and natural environments. He combines high-resolution models (Large Eddy Simulations, tree fluid dynamics) with multi-scale observations that link ecological state and function with atmospheric dynamics and hydrology. An additional focus of his research is incorporating environmental and remote sensing data in models of animal movement.
    • Speaker: Assaad Mrad, UC Irvine and Wake Forest University
    • Title: Modeling the spread of gas bubbles inside plants and their effect on photosynthesis during drought [slides]
    • Description: In this presentation, embolism spread in plant xylem will be modeled computationally and using network theory. It is established how embolism spread in xylem depends on the connectivity of microscopic water conduits. This process is upscaled to the organ level to give predicted vulnerability to embolism curves. Vulnerability to embolism curves are then further up-scaled to the whole-plant to evaluate the effect of soil water depletion on photosynthesis.
    • Speaker Bio: Assaad Mrad is an environmental scientist and, specifically, an ecohydrologist. He is interested in the role of vegetation in coupling the fluxes of water and carbon between land and atmosphere. His overarching research objective is to connect scientific advances spanning several scales. For example, how does the anatomy of plant xylem drive its behavior to droughts? He is currently a postdoc studying wildfire spread and the vegetation dynamics pre- and post-fire. As an engineer by training, he is interested in applying tools from physics and engineering to his environmental science questions. Such tools are graph theory, percolation theory, and the calculus of variation. He graduated with a Ph.D. in Environmental Science from Duke University in 2020 and a Bachelor’s degree in Mechanical Engineering from the American University of Beirut in 2016.
    • When: Friday, January 29th, 9am PST | 12pm EST | 5pm London | 2am (Sat, Jan 30th) Tokyo
    • Webinar host: Theresia Yazbeck, The Ohio State University
    • Contact us: [email protected]
    • See recording: https://youtu.be/T38z-YF1xRE

2020

  • Monday, November 30th, 2020
    • Speaker: Karina Williams, UK Met Office Hadley Centre and Exeter University
    • Title: Using fluxes to evaluate and improve land-surface models
    • Description: In this presentation, we will explore some of the ways that flux tower data is used to improve process representation within land-surface models, with particular focus on the way that vegetation responds to low levels of soil moisture in the JULES land-surface model.
    • Speaker Bio: Karina Williams is vegetation module leader for the JULES land-surface model. She co-leads a working group to evaluate and improve the process of water stress at all scales in the model, and coordinates a network of modellers of FACE sites within the JULES community. Dr. Williams completed both undergraduate and postgraduate studies in the Physics Department at Durham University, UK, and did a post doctorate at Bonn University, Germany. She joined the Met Office Hadley Centre in 2011. Since September last year, she has also worked part-time as a lecturer at Exeter University.
    • Speaker: Silvano Fares, National Research Council of Italy
    • Title: From flux measurement to a multi-layer canopy model for ecosystem services in urban areas [slides]
    • Description: In this presentation, we will introduce some history of research in flux measurements using enclosure systems and micrometeorological techniques to study plant-atmosphere exchanges. The focus will be in both CO2 and non-CO2 trace gases, with application of a multi-layer canopy model to predict exchanges and delivery of ecosystem services in urban areas.
    • Speaker Bio: Silvano Fares is a research director at the National Research Council of Italy–Institute of Bioeconomy. He joined the FLUXNETcommunity in 2007 during his PhD in Forest Ecology (University of Tuscia, Italy), and later as a Postdoc at the University of California–Environmental Science and Policy Department, USA in 2008-2010. He is currently the designated national coordinator of terrestrial ecosystems for Italy in the EU program ICOS (Integrated Carbon Observation System) and a SSC member of ILEAPS (Integrated Land Ecosystem Process Study). He is an ecophysiologist interested in exchange processes involving ozone, biogenic volatile organic compounds, methane and carbon between plant ecosystems and the atmosphere. With experience in flux measurement using both leaf-level enclosure systems and eddy-covariance techniques, he applies multi-layer canopy models to predict plant-atmosphere interactions under abiotic stress and estimate ecosystem services provided by urban trees.
    • When: Monday, November 30th, 8:30-9:30pm PST | 11:30am-12:30pm EST | 4:30-5:30pm London | 1:30-2:30am (Tue, Dec 1st) Tokyo
    • Webinar host: Fred Otu-Larbi, Lancaster University
    • Contact us: [email protected]
    • See recording on YouTube: https://www.youtube.com/watch?v=CVAItU0Iewg

  • Thursday, September 10th, 2020
    • Speaker: Jason Beringer, School of Agriculture and Environment, University of Western Australia
    • Title: OzFlux: from little things big things grow
    • Speaker Bio: Professor Jason Beringer studies how ecosystems, and the services they provide, will respond to climate change and future disturbances. He has conducted extensive research in Australia’s dry land ecosystems, considering interactions among fire, precipitation, and ecosystem productivity. As founding member and current Director of TERN OzFlux, he has overseen the growth of the network and co-hosted the 20th anniversary OzFlux meeting in the summer of 2020. View his biography here.
    • Speaker: David Campbell, Earth Sciences, University of Waikato, New Zealand
    • Title: The Kiwi EC connection – from peat to pasture
    • Speaker Bio: Associate Professor David Campbell joins us from the Waikato Biogeochemistry and Ecohydrology Group where he studies the carbon balance of New Zealand’s distinctive peatland and agricultural ecosystems. He was an early adopter of micrometeorological methods for measuring exchange of both carbon dioxide as well as methane. He is lead investigator at the only temperate bog site compiled as part of the FLUXNET methane synthesis from the southern hemisphere. View his full biography here.
    • Speaker: Caitlin Moore, School of Agriculture and Environment, University of Western Australia
    • Title: An early career researcher perspective of OzFlux
    • Speaker Bio: Dr. Caitlin Moore is a research fellow in the School of Agriculture and Environment, at the University of Western Australia. Caitlin got her PhD at Monash University studying tropical savanna productivity using a combination of eddy covariance and phenocam data, then completed a postdoctoral position studying bioenergy crops at the University of Illinois at Urbana-Champaign. Currently, she is bringing together new measurements and modeling techniques to better predict crop and native ecosystem stress in Western Australia. Caitlin serves as External Communications officer on OzFlux’s steering committee. View her full biography here.
    • When: Thursday, September 10th, 4:30-5:30pm PDT | 7:30-8-30pm EDT | 12:30-1:30am (Friday, 11th) London | 8:30-9:30am (Friday, 11th) Tokyo | 9:30-10:30am (Friday, 11th) Sydney | 11:30am-12:30pm (Friday, 11th) Auckland
    • Webinar host: Gavin McNicol, Stanford University
    • Contact us: [email protected]

  • Thursday, August 6th, 2020
    • Speaker: Takashi Hirano, Hokkaido University, Japan; Vice President of AsiaFlux and the former President of JapanFlux
    • Title: History and activities of AsiaFlux and JapanFlux
    • Speaker Bio: Professor Takashi Hirano from the Graduate School of Agriculture, Hokkaido University, Japan is the Vice President of AsiaFlux and former President of JapanFlux. He will share the history and activities of both AsiaFlux and JapanFlux in his experience as a senior scientist. Biometerology and ecosystem functions are his specialty, and his interests include the eddy flux technique in forest ecosystems, land use change, tropical and northern peatlands, agricultural meteorology and more. View his biography here.
    • Speaker: Masahito Ueyama, Osaka Prefecture University, Japan
    • Title: Expanding research interests with collaborations through surviving young days
    • Speaker Bio: Associate Professor Masahito Ueyama joins us from the Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Japan. He will speak on experiences as an early career professional within AsiaFlux and JapanFlux, which lead him to a position in ecological meteorology. He serves on the AsiaFlux and JapanFlux steering committees, amongst others, and currently researches methane fluxes and greenhouse gas emissions. View his full biography here.
    • When: Thursday, August 6th, 4:30-5:30pm PDT | 7:30-8-30pm EDT | 12:30-1:30am (Friday, 7th) London | 8:30-9:30am (Friday, 7th) Tokyo time
    • Webinar host: Gabriela Shirkey, Michigan State University
    • Contact us: [email protected]

 

  • Friday, June 26th, 2020
    • Speaker: Dennis Baldocchi, UC Berkeley
    • Title: Introducing FLUXNET: History and Founding
    • Description: Our inaugural meeting will feature Dennis Baldocchi, Professor of Biometeorology at University of California, Berkeley, who will speak about the history of eddy covariance flux measurements, it’s changing theory, methods, and applications, and the eventual establishment of FLUXNET. Professor Baldocchi helped pioneer the eddy covariance method and his research approach involves the coordinated use of long-term, quasi-continuous flux measurements and theoretical models to study biosphere-atmosphere interactions. Today, he is a co-investigator of the AmeriFlux Management Project, helping support the AmeriFlux and FLUXNET networks. Read his bio here.
    • When: Friday, June 26th, 8-9am PDT | 11a-12pm EDT | 4-5pm London | 12-1 am (27th) Tokyo time
    • Webinar host: Gabriela Shirkey, Michigan State University
    • Contact us: [email protected]