Seminars

Abstract
California’s water system is among the most complex and engineered in the world, spanning vast geographic, climatic, and institutional scales. Its two major interlinked conveyance networks, the State Water Project (SWP) and the Federal Central Valley Project (CVP), collect, store, and transport water over ~1000 km from northern headwaters to southern agricultural and urban centers. Together, they sustain irrigation for >1.2 million ha of farmland and provide drinking water for more than 23 million people. However, these systems—originally designed in the mid-20th century—now face mounting challenges from climate change, ecosystem degradation, and groundwater depletion. Reduced snowpack, intensifying droughts, and shifting precipitation patterns strain both surface and subsurface storage, with cascading consequences for the state’s energy, agriculture, and ecological resilience. Substantial groundwater losses due to agricultural pumping during droughts (up to ~15,000 cubic hectom), highlighting the urgency of sustainable management. Implementation of the Sustainable Groundwater Management Act (SGMA) and investments in drought resilience innovation programs represent critical steps toward adaptation. Yet, balancing competing demands among agricultural, urban, and environmental sectors remains a formidable task. This seminar explores these ‘basics’ of California water and just some of the many technical, ecological, and policy dimensions of California’s water infrastructure under climate stress, including interdependencies between energy use, biodiversity, and water supply reliability. By integrating hydrological science with adaptive governance, California’s water future offers a global case study in managing scarcity within complexity. What can we learn from other countries in similar situations?

Bio 

Steve Blumenshine is the Executive Director of CSU-WATER. CSU-WATER (Water Advocacy Towards Education and Research) develops and strengthens water research and scholarship in the California State University System and throughout CA in collaboration with external partners and other water stakeholders. These efforts focus on including faculty and students throughout the 23 campus CSU System to address critical water resource issues and agricultural, urban, and environmental water allocations. We focus heavily on connecting students with agencies to support urgent water workforce needs. CSU-WATER also engages in research including climate, energy, and community issues. Prior to CSU-WATER, Steve was the Director of the Research & Education Division of the California Water Institute at Fresno State. He was a faculty member for 20 years in the Fresno State Biology Department where he taught and operated a very active freshwater & estuarine research lab with many students and external collaborators. Blumenshine’s international water research experience includes two U.S. Fulbright Awards, and engagement in Thailand, Germany, Israel, Switzerland, China, Australia, and Spain. His degrees include a PhD from the University of Notre Dame, MS from George Mason University, and BS at the University of Wisconsin.

ONLINE

Abstract

Although some prior research suggested little benefit in forecasting skill when horizontal grid spacing is reduced below 3 km for simulation of convection, it appears some important aspects of thunderstorms are better depicted with 1-km grid spacing than with 3-km.  In particular, upscale growth happens faster in 1-km runs, because new convection is initiated by gravity waves, whereas in 3-km runs, new cells wait until cold pool boundaries collide. In addition, 1-km runs simulate more bow echoes, with a frequency better agreeing with observations, as it appears storm-scale processes are able to initiate bowing, whereas in 3-km runs, other larger-scale features such as strong storm-relative inflow or the presence of mesoscale boundaries, may need to be present to trigger bowing in most cases. Finally, the challenges of forecasting the most damaging single thunderstorm event in United States history, the 10 August 2020 derecho, along with the mechanisms that allowed winds to exceed 60 m/s and last for up to an hour in some locations, will be discussed using 1-km and 3-km runs from the FV3, WRF, and MPAS models.

BIO

Dr. William Gallus is a Distinguished Professor of Meteorology at Iowa State University, starting his career there in 1995.  He received his PhD in Atmospheric Science in 1993 at Colorado State University. During his career, he has published over 120 refereed papers, and given over 250 conference presentations, generally focused on the use of numerical weather prediction models to better understand and forecast mesoscale phenomena, particularly heavy thunderstorm rainfall and severe weather. He has mentored 140 undergraduate student research projects and nearly 60 graduate students. He has received several teaching and research awards at his university, and the T. Theodore Fujita Research Achievement Award from the National Weather Association for his significant research contributions to operational meteorology.

Link

ABSTRACT
A wave of unprecedented extreme weather events, breaking records worldwide, has raised urgent questions about the ability of current weather and climate models to anticipate the emerging impacts of climate change on human life and infrastructure. Among these, extreme wind speeds and gusts, often associated with midlatitude cyclones and low-level jets, pose a growing threat to critical sectors of society. In this talk, I will first present projections of near-surface extreme winds over the midlatitudes of both hemispheres under an idealized warming scenario, based on CMIP-class models. I will then illustrate how global kilometer-scale simulations may provide new insight into how the structure and intensity of North Atlantic midlatitude cyclones respond to climate warming. Finally, I will discuss results from a set of experiments with the GFDL-AM4 model that  incorporate improved turbulence representation via the CLUBB scheme. These highlight the role of prognosed momentum fluxes in better  capturing low-level jet dynamics and improving the simulation of the diurnal precipitation cycle. Together, these studies demonstrate the importance of refined physics and high-resolution modelling for advancing our understanding and prediction of wind extremes in a warming climate.

BIO
Emanuele Silvio Gentile is an atmospheric physicist and climate modeler, with a background in theoretical physics. His research combines
kilometre-scale climate models, higher-order turbulence physics, and emerging AI and machine learning tools to investigate how moist convection and sub-grid turbulent processes shape near-surface extremes, and how mesoscale weather responds to climate change. He studies the Earth's climate as an interconnected system, linking atmospheric dynamics with land, ocean, and wave interactions.

He is currently a Research Scientist at NCAS and the University of Reading, working within the CANARI project to run very high-resolution
simulations that assess how climate change is altering heavy precipitation, inland flooding, and extreme winds across the UK and North Atlantic. Previously, Emanuele worked at NOAA's Geophysical Fluid Dynamics Laboratory and Princeton University, where he collaborated with Ming Zhao and Leo Donner to advance the representation of boundary-layer turbulence, convection, and clouds in GFDL's AM4 model. He holds a PhD in Atmosphere, Ocean, and Climate from the University of Reading and a First-Class Honours degree in Theoretical Physics from Imperial College London, where he received the Tessella Prize for innovative use of computational techniques in physics. He is original from Bologna where
he was born and raised.

ONLINE

Forecasting Heavy Precipitation Events (HPE) in the Mediterranean is crucial but challenging due to the complexity of the processes involved. In this context, Artificial Intelligence methods have recently proven to be competitive with state-of-the-art Numerical Weather Prediction (NWP). Our work focuses on improving the prediction of the occurrence of HPE over periods from 1 h to 24 h based on Neural Network (NN) models. It uses both ground-station observations (OBS) and data from Meteo France’s Arome and Arpege NWP models, on two regions with oceanic and Mediterranean climates, respectively, for the period 2016-2018. Our verification metric is the Peirce Skill Score (PSS).

Our results show that the NN model using only OBS or NWP data performs better for shorter and longer rainfall accumulation period, respectively. In contrast, a hybrid method combining both OBS and NWP data offers the best performance and remains stable with the rainfall accumulation period. The hybrid method also improves the performance in predicting increasingly intense rainfall, from the 5 % to the 0.1 % rarest events. We also find that the choice of a balanced loss function---i.e. one that takes into account the under-representation of rare events---is crucial for not missing actual events and significantly improves performance. Therefore, we propose a balanced loss function based on the PSS that improves greatly the prediction of HPE. Finally, the hybrid method is particularly well suited for the prediction of HPE in the Mediterranean climate, especially during the fall season, period during which most HPE occur.

Link: https://teams.microsoft.com/l/meetup-join/19%3ameeting_YjI1ZGNjOGMtZTc5Zi00ZDg3LTgzOGQtOGE5YTU0YjI5MjBj%40thread.v2/0?context=%7b%22Tid%22%3a%2234c64e9f-d27f-4edd-a1f0-1397f0c84f94%22%2c%22Oid%22%3a%2205de29bc-843a-4657-ba7b-de69220f4f51%22%7d

Abstract

The reactivity of the hydroxyl radical (OH), which is the inverse of its lifetime, provides valuable information on the number of pollutants in an air parcel, since the OH radical reacts with all trace gases. In my group at Forschungszentrum Jülich, we measure OH reactivity using the laser photolysis laser-induced fluorescence (LP-LIF) technique.

This measurement technique has enabled us to explore a wide range of scientific questions over the years, from measuring elementary rate coefficients to investigating OH radical recycling in experiments conducted in the atmospheric simulation chamber SAPHIR. Recently, a more portable set-up was deployed on the DC8 aircraft during the AEROMMA campaign to quantify the contribution of volatile chemical products (VCPs) to ozone production in mega-cities in the USA. I will provide an overview of our recent activities and findings.

Short Bio

Her research focuses on the experimental study of atmospheric radical chemistry, in particular organic peroxy radicals which plays a key role in determine type and amount of secondary pollutants formed. The current push to reduce emissionsin particularly from traffic and industrues is changing the chemical enviorment in urban areas. Reactions pathways are now becoming available for organic peroxy radicals which need to be investigated with chamber experiments and field studies. Working together with scientist from different backgrounds and countries, participating to field campaigns and performing chamber experiments contributing to a better understanding of how primary emissions are oxidized to secondary pollutants is what motivates her research.

ONLINE

ABSTRACT

The Center for Western Weather and Water Extremes (CW3E) mission is to provide 21st Century water cycle science, technology, and outreach to support effective policies and practices that address the impacts of extreme weather and water events on the environment, people, and the economy of Western North America. To fulfill its mission, CW3E scientists and engineers develop predictive capabilities based on physics-based, deep learning, and data-driven models. Those generate accurate and reliable estimates of precipitation and other atmospheric and hydrologic variables and are utilized by water managers across the Western US for reservoir operations, as part of the Forecast Informed Reservoir Operations Program. The goal is to maximize the water supply and reduce the risk of flooding, for an effective climate adaptation strategy. We will describe these prediction methods, which include a version of the Weather Research and Forecasting model tailored for the prediction of extreme weather associated with atmospheric rivers over the Western US (West-WRF), a 200-member ensemble at 9-km based on West-WRF, and a deep learning algorithm applied in a postprocessing framework to the 200-member ensemble. We will also present a recently developed, high-resolution (6-km), artificial intelligence (AI) data-driven weather model. We will discuss its ability to learn the underlying physical processes and how it can be used to generate very large ensembles (+1000 members), to better sample the tails of the distribution and more reliably predict extreme weather.

SHORT BIO

Dr. Luca Delle Monache is the Director of Research of the Center for Western Weather and Water Extremes (CW3E), Scripps Institution of Oceanography, University of California San Diego. Dr. Delle Monache oversees the research and development of the Center’s modeling, data assimilation, postprocessing, artificial intelligence, hydrology, subseasonal and seasonal, and supercomputing capabilities, with the goal of maintaining state-of-the-art models and tools while actively exploring innovative algorithms and approaches. In close coordination with the Center Director and the management team, he develops new scientific and programmatic strategies to maintain and further expand CW3E leadership on understanding, observing, and predicting extreme events in Western North America and other regions across the world. His interests include predicting extreme weather and water events via numerical weather prediction, data assimilation, artificial intelligence, and the design of ensemble methods for probabilistic prediction and uncertainty quantification. He has also made several contributions to renewable energy and air quality. He earned an M.S. in Mathematics from the University of Rome, Italy, an M.S. in Meteorology from San Jose State University, U.S., and a Ph.D. in Atmospheric Sciences from the University of British Columbia, Canada.

ONLINE

Abstract

Understanding the impact of climate change on groundwater recharge is crucial for the sustainable management of aquifers. Numerical models assist regulatory agencies in licensing decisions, but they rely on estimates of recharge fluxes that can be highly uncertain. Furthermore, management strategies in response to climate change face challenges such as the lack of empirical data to validate predicted changes or backing up processes that are not entirely understood.

By applying multiple estimation methods, using the data collected at seven locations in Western Australia, we emphasize the importance of deploying monitoring stations based on different sensor typologies. We delve into the biophysical processes that dictate the mechanism of groundwater recharge and highlight how the climatic variables and the vegetation response influence the dynamics and characteristics of wetting fronts. 

The insights obtained from this type of station can be utilised to understand the effect of diverse land uses, soil types, and climatic drivers on recharge and evapotranspiration fluxes. Estimates can then be benchmarked against broader observations, such as data provided by remote sensing or borewell measurements, while quantifying different sources of uncertainty (e.g. methodological or epistemic), generating robust databases useful for water resources models.

Bio

Simone is a Marie Curie research fellow at the DAGRI within the Universita' di Firenze and CNR - ISAC in Bologna. He spent 4 years at UWA in Perth after completing a joint PhD between Monash University in Melbourne and CSIRO Land & Water. With an international background in Hydraulic and Environmental Engineering (University of Pisa - Italy ), and a PhD in civil engineering (Monash and CSIRO), his experience spans hydrology, numerical modelling, field data collection, quantitative hydrology, remote sensing and model-data fusion techniques. He is passionate about water, vegetation and their intricate connection in the natural and built environment.

Link: https://meet.goto.com/932307501

Abstract
Biosphere-Atmosphere interactions represent the feedback processes between plant (and organisms functioning) and atmosphere processes as these relate to carbon and water cycles. While these bio-physical processes are becoming better understood, the role of the biosphere, namely biodiversity in terms of composition and functioning remains poorly understood. The development of remote sensing sensors, data and techniques has now enabled us to not only assess change in land cover and its change, but also obtain information on plant traits and proxies of biodiversity fundamental for biosphere-atmosphere interactions, and assessing the role of human activities. In this presentation I will show (i) recent advancements of remote sensing to measure biodiversity and plant traits, (ii) the potential effect of changes in plant traits on fundamental water variables that determine moisture recycling flows, and (iii) how moisture recycling is fundamental to the maintenance of the Amazon and the regulation of our global climate system.

Bio
Maria is a Professor in Earth System Sciences at the University of Zurich in Switzerland. She holds a doctoral degree in Ecology from the University of California Davis. Her research asks questions around the co-evolution of social-ecological systems, a fundamental step to place Earth System Sciences in the context of the Anthropocene. Her approach is interdisciplinary, and observes, describes, measures drivers and their impact, and models the interactions and feedbacks between Earth System spheres and the human system.

IT
Maria è docente di Earth System Science presso l'Università di Zurigo, in Svizzera. Ha conseguito un dottorato in Ecology presso l'Università della California Davis. La sua ricerca riguarda la coevoluzione dei sistemi socio-ecologici, un aspetto fondamentale per studiare le Scienze del Sistema della Terra nel contesto dell'Antropocene. Segue un approccio interdisciplinare, attraverso l'osservazione, descrizione e misura dei driver e del loro impatto, e la modellizzazione di interazioni e feedback tra le componenti del Sistema Terra e il sistema umano.

SEE IT ON YOUTUBE

Abstract - In general usage, ‘storylines’ are causal explanations which help to make sense of a real or imagined situation or sequence of events. They are distinguished from predictions by the incorporation of contingent (i.e. unpredictable) causal factors. Storylines have an obvious power in literature and drama. But they have a pedigree in science too, notably in natural history. Recently, storylines have become an accepted tool within climate science, defined by the IPCC as “a self-consistent and plausible unfolding of a physical trajectory of the climate system, or a weather or climate event, on time scales from hours to multiple decades”. In this talk, I will discuss the rationale behind physical climate storylines, some of the ways in which they have been used to make sense of climate change in situations involving deep (i.e., hard-to-quantify) uncertainty, and some of the questions which keep cropping up whenever I talk about storylines.

Bio - https://research.reading.ac.uk/meteorology/people/ted-shepherd/

Link to join the seminar online - https://meet.goto.com/932307501

Abstract

Water vapor, clouds and precipitations: exploiting remote sensing and machine learning 
to better understand the atmospheric water cycle
In a changing climate a thorough understanding of the water cycle and especially the local availability of water resources is crucial. This holds especially for desert areas where often very view measurements are available. Modern remote sensing techniques and in particular recent satellite launches provide unique possibilities to study water vapor, clouds and precipitation from the satellite perspective. However, satellite measurements are especially challenging close to the surface calling for ground-based and airborne measurements to allow a complete assessment. With more and more data from observations but also high-resolution modelling intelligent methods are necessary to extract the essential information. 

The talk will start with an introduction to the Center for Earth Observation and Computational Analysis (CESOC; hcesoc.net) which has been founded between the Universities of Bonn and Cologne and the Research Center Jülich. CESOC drives the integration of Earth System Science with Computer Science and connects the European Center for Medium Range Weather Forecast (ECMWF), specifically its Bonn location. Next I will give a short overview on the activities of the Atmospheric Water Cycle and Remote Sensing (AWARES) group before providing specific example from two “dry” regions: 1) The Arctic where the strongest changes in the coupled climate system are observed and studied within the Collaborative Research Center (CRC) “Arctic Amplification”, 2) The Atacama desert, the driest place on Earth whose evolution is investigated within the CRC “Earth at the dry limit” and where the westward located stratocumulus deck seems to be connected to a region of cooling opposite to the global trend. 

Bio

Link to join the seminar online https://meet.goto.com/932307501