Events

Dr. Mukund Rao  is currently an Assistant Research Professor at Columbia University’s Lamont-Doherty Earth Observatory

Abstract: The magnitude of the terrestrial carbon sink remains a key uncertainty in future climate projections, in part due to poorly understood links between carbon uptake and its allocation to woody biomass in vegetation. Here, we show that photosynthesis and above-ground growth occur asynchronously across diel to seasonal scales in eight North American oak species. Across 137 tree-ring sites, current-year annual growth was insensitive to climate variability after mid-summer despite 26-36% of annual gross primary productivity (GPP) occurring during this period. Hourly GPP flux and growth measurements at four sites spanning seven site-years further demonstrate that wood formation ceases earlier than photosynthesis and is restricted to periods of low atmospheric aridity and temperature. This photosynthesis-growth decoupling intensifies with inter-annual variability in vapour pressure deficit (r=0.86, p<0.05), suggesting that by assuming tight coupling between photosynthesis and woody biomass, current earth system models may overestimate long-term carbon sequestration in forests. I will also introduce a collaborative paired flux tower, in-situ remote sensing, dendrometer network comprising 19 locations across 13 countries, which we intend to harness to evaluate these questions across continental scales. We extend an invitation to members of the community to join, collaborate, and contribute to this synthesis.

About: Dr. Mukund Rao is an Ecoclimatologist and Carbon Cycle Scientist. He is currently an Assistant Research Professor at Columbia University’s Lamont-Doherty Earth Observatory. He received his PhD in October 2020 from Columbia University. He was then an Adjunct Professor of Environmental Studies at New York University (NYU), a NOAA Climate & Global Change fellow at University of California Davis (2021-2022), and subsequently a Marie Skłodowska Curie Fellow at the Center for Ecological Research and Forestry Applications (CREAF), Barcelona, Spain (2022-2024). His research aims to illuminate the future of ecosystems and the forest carbon cycle in a changing climate by drawing on his expertise in climate science, plant ecophysiology, dendrochronology, earth system models, and remote sensing. His research spans a broad array of spatial and temporal scales from cells to satellites and seconds to centuries. He is currently working on projects related to the role of tree growth in the forest carbon cycle, the vulnerability of forests to increasing heat waves, and the use of dendrochronology to understand past environmental change and timber transport.

Dr. Haruko Wainwright is an assistant professor of Nuclear Science and Engineering, and Civil and Environmental Engineering at the Massachusetts Institute of Technology.

Abstract: Watershed science requires characterization and monitoring across interconnected bedrock-to-canopy compartments. Particularly, in snow-dominated mountainous watersheds of the western United States, subsurface water storage following snowmelt plays a central role in streamflow generation and ecosystem productivity. Recent advances in remote sensing technologies—including airborne LiDAR, hyperspectral imaging, and electromagnetic surveys—along with the growing availability of low-cost distributed in situ sensors have greatly expanded observational capabilities. However, integrating these heterogeneous, multiscale datasets into a coherent understanding of watershed function remains a major challenge. This talk presents machine-learning approaches for capturing spatial heterogeneity and temporal dynamics of hydrological and ecosystem processes in snow-dominated mountainous watersheds. First, unsupervised learning—specif cally clustering—is an powerful approach to characterize bedrock-to- canopy co-variability in heterogeneous watersheds where ground-truth data are limited. We introduce a watershed zonation framework that integrates multiple spatial data layers to identify subsystems with distinct distributions of bedrock-through-canopy properties, providing a semi-quantitative basis for understanding the bedrock-to-canopy co-evolution as well as guiding monitoring and sampling strategies. Supervised regression is then employed to spatially distribute difficult-to-measure parameters, such as soil and bedrock properties, at the watershed scale. Second, we present a physics-informed machine- learning framework that integrates real-time in situ sensor data with vadose-zone flow simulations for near-surface soil-moisture monitoring and forecasting. This approach combines ensemble Kalman filtering for data assimilation with a Flow Map Learning–based emulator to accelerate model prediction during assimilation. Together, these applications demonstrate how ML and AI methods can enhance data integration, computational efficiency, and predictive capability in watershed science.

About: Dr. Haruko Wainwright is an assistant professor of Nuclear Science and Engineering, and Civil and Environmental Engineering at the Massachusetts Institute of Technology. Before joining MIT, she was a Staff Scientist in the Earth and Environmental Sciences Area at Lawrence Berkeley National Laboratory. Her research focuses on environmental informatics, aiming to improve understanding and predictions in Earth and environmental systems through mechanistic modeling and machine learning.

Dr. Rachel Schaefer is the winner of the 2024 Lorenz G. Straub Award

Seagrass in Motion: Hydrodynamics as a Driver of Coastal Ecosystem Services

Meadows of aquatic vegetation such as seagrass modify the flow of water and transport of sediment in the environment. The hydrodynamic drag generated by a seagrass meadow contributes to the wide range of ecosystem services it provides, which includes quiescent habitat for other species, wave damping, water quality enhancement, and carbon sequestration. However, the hydrodynamics of seagrass meadows in combined wave and tidal current conditions, which realistically many meadows experience, is not well understood. My dissertation investigates how interactions among seagrass, waves, currents, and sediment influence the provision of ecosystem services. In this talk, I will give an overview of the laboratory, numerical, and field experiments I used to explore these interactions. I will highlight the role of plant flexibility in shaping hydrodynamic drag, flow structure, and wave energy dissipation. Ultimately, this work can inform restoration project design, carbon credit methodology, and nature-based solutions for coastal resilience and climate mitigation.

About: Rachel grew up in New Jersey and earned a bachelor’s degree in civil engineering from the University of Delaware, where she developed a strong interest in coastal engineering and nature-based solutions. She completed her Ph.D. in civil and environmental engineering at the Massachusetts Institute of Technology (MIT) in 2024 as a National Science Foundation Graduate Research Fellow under the advisement of Dr. Heidi Nepf. Her research combined laboratory, field, and numerical approaches to investigate how plant–flow interactions influence wave dissipation and carbon sequestration in coastal systems. She later worked as a postdoctoral researcher on a climate resilience project with the United States National Park Service. Rachel is currently a research engineer in the catastrophe modeling industry.

We will also be celebrating the winners of the 2025-2026 SAFL Student Awards!

Alyssa Connaughton - Edward Silberman Fellowship

Roozbeh Ehsani - Edward Silberman Fellowship

Saswata Basak - Heinz G. Stefan Fellowship

Ziyan Ren - Charles C.S. Song Fellowship

Dr. Bin Liu is an Associate Professor of Physics at the University of California, Merced.

Abstract: Symmetry and geometry are principles that have been used to understand motion and structures across disciplines and to robustly approach distinct phenomena. By applying these symmetries and geometries to microscale flows, we can reveal surprising transport behaviors in fluids and their entrained microorganisms. In this talk, I will first demonstrate that geometry can be an unexpected factor in determining bacterial transport in structured media, introducing an anomalous dependence on cell size: short cells are often trapped, while long cells navigate smoothly through structures. Additionally, I will present the use of symmetry principles, including symmetry groups, to separate fundamental functions of microfluidic flows, such as trapping and displacing particles. This separation of functions introduces new capabilities in microfluidics, enabling accurate and multiplexed manipulation of microscale particles without perturbations, as orthogonal to traditional trap-based micromanipulation methods.

About: Dr. Bin Liu is an Associate Professor of Physics at the University of California, Merced. He received his Ph.D. in Physics, followed by a postdoctoral stay at the Courant Institute of Applied Mathematics at New York University. Before joining UC Merced, he conducted his postdoctoral research at Brown and Cornell University, studying a variety of biology-inspired physics problems. His research interests focus on the underlying geometric, topological, and symmetry-based principles in complex mechanics, especially those involved in bacterial transport and cell-environment interactions. Dr. Liu is a Hellman Fellow and a recipient of NSF CAREER Award in 2020.

Dr. Kelin Whipple is currently a Professor at School of Earth and Space Exploration at Arizona State University.

Abstract: The Hawaiian islands are an excellent natural laboratory for studying the controls on long-term landscape evolution because (1) both landscape age and initial condition are known, (2) rock properties are generally uniform (but locally heterogeneous), (3) most of the global variation in annual rainfall is represented, and (4) there is no tectonics beyond the known subsidence history. Our work reinforces the perspective that much of landscape evolution – primarily canyon cutting – is a threshold-limited process. We show that commonly neglected thresholds largely define the relationship between climate and landscape evolution. Our work is unusual in that most studies of the role of thresholds in modulating climate control of erosion have been conducted in tectonically active settings where a balance between rock uplift and erosion rate creates opportunities researchers can exploit. Interestingly, however, it is the lack of tectonic activity in the Hawaiian islands that ultimately makes them better suited to definitively establish and quantify the role of thresholds in landscape evolution.

About: Dr. Kelin Whipple is a geomorphologist focused on active processes and landscape evolution in tectonically active mountain ranges. Kelin was born in Michigan, but grew up in the highlands of Ethiopia, where his love of the outdoors and exploring landscapes was born. Kelin received an A.B. in Geology at the University of California, and an M.S. (1989) and Ph.D. (1994) in Geological Sciences at the University of Washington. Kelin worked for one year as a postdoctoral fellow at the St. Anthony Falls Hydraulic Laboratory of the University of Minnesota before starting his first faculty appointment at the Massachusetts Institute of Technology in 1995. In 2006, Kelin moved to Arizona State University as part of the development of the new School of Earth and Space Exploration. His research focuses on the interactions among climate, topography, and tectonics.

Dr. Gokul Pathikonda is an Assistant Professor in the School for Engineering of Matter, Transport and Energy (SEMTE) at Arizona State University.

Abstract: With the advances in scale-resolving measurement techniques for complex flow environments, we have gained a mature understanding of dominant coherent structures that populate a canonical turbulent boundary layers. For this seminar, we discuss two examples of the complex interplay of turbulent scales that significantly affects the world we live in. First, we look at the dispersion of a passive scalar plume that is injected into a high Reynolds number () turbulent boundary layer using. simultaneous planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV). We focus on the role of the large coherent structures that populate such boundary layers on the break- up, meandering, and dispersion of the scalar plume at early stage. These structures significantly alter the long-range concentration intermittency and instantaneous concentrations further downstream – understanding which is critical for modeling pollutant, aerosol, and particulate transport in atmospheric boundary layers over complex terrains. In a second contrasting example, we present preliminary efforts where we can externally perturb these flows and coherent mechanisms to mimic real-world unsteadiness (such as gusts, vortex-wing interactions, etc.). We do this to study the ensuing changes to the boundary layer behavior such as separation, scalar transport, etc. To this end, we present a ‘Translating Rotating Cylinder’, ‘Dynamic Aspiration System’, and a class of herringbone-type 2D and 3D roughness patterns to discuss their effects.

About: Dr. Gokul Pathikonda is an Assistant Professor in the School for Engineering of Matter, Transport and Energy (SEMTE) at Arizona State University. His team designs laboratory experiments to identify and measure fundamental turbulence behavior relevant to aerospace, energy, astrophysics, maritime and atmospheric sciences. Specifically, they design innovative boundary layer control approaches and hybrid application of laser-based techniques (particle image velocimetry, laser- induced fluorescence, etc.) to study wall-bounded turbulent flows, shear-= driven turbulent mixing, and reacting flows. He is a recipient of 2025 ONR Young Investigator Award, Stanley Weiss Outstanding Dissertation Award and RISE Fellowship. He received his PhD in 2017 in Theoretical and Applied Mechanics from University of Illinois, Urbana-Champaign, and was a researcher at Georgia Tech, Indian Institute of Science and Jawaharlal Nehru Center for Advanced Scientific Research at Bangalore.

Dr. Eric W. Seabloom is a Distinguished McKnight University Professor and Interim Director at the University of Minnesota

Abstract: Cedar Creek Ecosystem Science Reserve encompasses 2200 ha of wetlands, lakes, forests, savannas, and grasslands in central Minnesota and supports a diverse array of plant and animal communities. For over eight decades, Cedar Creek researchers have been advancing our understanding of aquatic and terrestrial ecosystems. For the last four decades CCESR also has hosted the NSF funded Cedar Creek Long Term Ecological Research site (LTER), which has supported some of the longest running and most impactful ecological experiments worldwide. I will provide a brief overview of research at Cedar Creek, highlighting some of the unique insights arising from multi- decadal experiments quantifying the ecosystem impacts of altered climate, nutrient cycles, disturbances, and species extinctions. I also will provide an overview of unique opportunities for new research, education, and outreach activities leveraging the unique landscape, research history, infrastructure, and collaborative community at Cedar Creek.

About: Dr. Eric W. Seabloom is a Distinguished McKnight University Professor and Interim Director at the University of Minnesota with expertise in community ecology, disease ecology, and ecosystem science. His research focuses on the long-term dynamics of grassland ecosystems, with a particular emphasis on the effects of nutrient enrichment, invasive species, plant pathogens, and herbivory. He is a lead PI of Cedar Creek Long Term Ecological Research (LTER) Site and a coordinator of the globally distributed NutNet and DRAGNet experiments.

Dr. Yunxing Su is an Assistant Professor in the Department of Mechanical and Industrial Engineering at the University of Minnesota Duluth.

Abstract: Flows interacting with moving bodies give rise to rich fluid–structure dynamics that govern energy transfer, transport, and mixing across scales. This talk examines how these mechanisms link engineered and biological systems through a shared fluid-mechanical framework. I will first discuss work on energy harvesting using oscillating foils, where resonance, wake coupling, and vortex dynamics dictate performance and efficiency. I will then present studies on aquatic locomotion, focusing on how jellyfish and copepods generate thrust and induce mixing. Using a combination of time-resolved flow visualization and cyber-physical experiments, we characterize vortex dynamics, flow-induced forces, and the resulting transport pathways. Finally, I will highlight how these controlled laboratory investigations inform our understanding of biogenic mixing and environmental transport processes. Together, these studies aim to bridge canonical fluid–structure interaction with environmental fluid mechanics and reveal new opportunities for integrating experimental, analytical, and modeling approaches across scales.

About: Dr. Yunxing Su is an Assistant Professor in the Department of Mechanical and Industrial Engineering at the University of Minnesota Duluth. His research examines fluid dynamics at the intersection of engineering, biology, and environmental science, with a focus on renewable energy harvesting, aquatic locomotion, bio-inspired robotics, and environmental fluid mixing. Before joining UMD, he was a Research Associate at the University of Colorado Boulder and a Postdoctoral Associate at Brown University, where he also earned his Ph.D. in Fluids and Thermal Sciences.

Dr. Shuna Ni is an Assistant Professor of Fire Protection Engineering at the University of Maryland, College Park.

Abstract: Wildland–urban interface (WUI) fires increasingly threaten communities, yet the coupled processes governing structure ignition, burning, collapse, and subsequent fire spread remain insufficiently understood. This study integrates numerical simulation and experimental investigation to elucidate these interactions. Using the NIST Fire Dynamics Simulator (FDS), the burning of a two-story source structure and the ignition of an adjacent target structure during the 2023 Lahaina fire were simulated. The results demonstrate that wind direction and vegetation have a strong influence on inter-structure fire spread and ignition timing. Complementary fire tests on small-scale timber structures examined how external fire exposure, structure configurations, and compartment openings affect fire development and spread, structure collapse behavior, and its feedback on fire dynamics. Different collapse modes were observed, and structure collapse was found to intensify burning and generate large quantities of embers, promoting further fire spread in WUI environments. Collectively, the modeling and experimental results highlight the interconnected processes of structure ignition, burning, collapse, collapse-induced fire intensification, and structure-to-structure fire spread, providing essential insights for performance-based design and fire resilience in WUI communities.

About: Dr. Shuna Ni is an Assistant Professor of Fire Protection Engineering at the University of Maryland, College Park. Ni’s research focuses on fire forensics, fire resilience of wildland-urban interface communities, structural fire engineering, impact of fire on civil infrastructure, and fire safety of tall mass- timber buildings. Her research has been funded by the National Science Foundation, National Institute of Justice, Fire Protection Research Foundation, University Transportation Centers, BLM-National Interagency Fire Center, Grand Challenges Grants Program at the University of Maryland, and industrial partners such as FM.

Read About the Nels Nelson Memorial Fellowship

Distinguished Lecture: Tailings Dam Breach Analysis: Evolution and Challenges

Abstract: This presentation traces the history and development of dam breach analysis with a particular focus on its adaptation to tailings dam breach analysis (TDBA). Unlike conventional water-retaining dams, tailings dams are designed to store mining waste—primarily fine sediments—in surface tailings storage facilities (TSFs). Tailings are typically transported to TSFs as slurry via pipelines and pumps. As the slurry settles, a permanent pond with a fluctuating water level forms in the TSF. As a result, a TSF with a permanent pond resembles a man-made reservoir with an earthen dam, where the volume of water is significantly smaller than in conventional dams, and the reservoir is predominantly filled with fine sediments. 

There are two key differences between conventional water-retaining eathern dams and tailings dams when performing breach analysis: 

1. In the event of a tailings dam failure, the tailings within the TSF may be mobilized due to liquefaction (if they are liquefiable) and erosion (if an active pond is present). The volume of mobilized tailings is unknown and can be challenging to estimate.
2. The materials stored  behind a tailings dam may include water, sediments and occasionally other fluids. If a dam were to fail, the resulting flood wave may behave like a water flood, mud flood, mudflow, flow slide, or slumping event. 

Given these complexities, it is essential to understand the geotechnical characteristics of the tailings in the TSF and to consider the potential failure mode when performing a TDBA. 

This presentation highlights how these factors are integrated into current TDBA practices and discusses the contributions of the Canadian Dam Association’s working group, which developed the first guidelines for tailings dam breach analysis.

About the Distinguished Speaker: Omid M. Mohseni is a senior water resources engineer and a vice president at Barr Engineering Co. (Barr). He earned his B.S. in Civil Engineering from the University of Science and Technology of Iran in 1986, and his M.S. and Ph.D. in Civil Engineering from the University of Minnesota’s St. Anthony Falls Laboratory in 1995 and 1999, respectively. Omid joined Barr in 2001, then returned to the St. Anthony Falls Laboratory in 2003, where he served as Associate Director of Applied Research until 2008. He rejoined Barr that same year and has been with the firm since. Until 2021, he also held an adjunct associate professorship at the University of Minnesota, where he taught courses in hydrology, open channel hydraulics, and hydraulic structures. Throughout his career, Omid has led and contributed to a wide range of projects involving watershed hydrologic analysis and modeling, stormwater best management practices (BMPs), stream temperature analysis, hydrodynamic modeling of lakes and rivers, design and analysis of hydraulic structures, and dam breach assessments. He has analyzed, managed, and reviewed breach analyses for more than 70 water-retaining and tailings dams across North America, South America, Africa, and Asia. In addition, Omid served on the Canadian Dam Association’s working group that developed the first set of guidelines for tailings dam breach analysis.

Nels Nelson Memorial Fellowship Recipient:  Michael Chiappone, Department of Earth and Environmental Sciences, advised by Peter Makovicky.

About Michael Chiappone: As a vertebrate paleontologist, he studies the processes by which animal bones begin the road to fossilization (taphonomy) in fluvial environments. He runs actualistic experiments in flumes to examine how bones can be transported, sorted, and buried to form real-world fossil sites from which paleontological data is derived.