News Article | December 12, 2016
Berkeley Lab scientists will present on a number of topics including climate modeling challenges, projects on Arctic permafrost, induced seismicity, cloud physics, Amazon forests, hydraulic fracturing, melting ice sheets, cool roofs, and more. And meet some of our scientists! They will be in the exhibit hall all week at booth #705. Mountainous watersheds in the Upper Colorado River Basin play a critical role in supplying water and nutrients to western North America. Ecosystem functioning in those regions - including plant dynamics and biogeochemical cycling - is limited by water availability. Under climate change, early snowmelt and increasing temperature are expected to intensify the drought conditions in early growing seasons. The objectives of this study are to map the regions where the plant dynamics are relatively more sensitive to drought conditions based on historical satellite and climate data, and to identify the environmental controls on drought sensitivity. Atmospheric rivers are narrow filaments of concentrated water vapor in the atmosphere whose presence has been connected to major flooding events along the West Coast of North America (California) and Western Europe (the UK). How to detect extreme weather phenomena like atmospheric rivers in climate datasets? The purpose of this research is to analyze large, high-dimensional climate datasets using Topological Data Analysis (TDA). The researchers are interested in the application of topological methods to other problems: extending similar concepts for extracting three-dimensional jet streams in the upper atmosphere, with the goal of characterizing activity and effects on storm systems. Uncertainty in Extreme Precipitation Representation in Numerical Simulations and Hydrological Datasets Understanding extreme weather is imperative to society, particularly given the growing body of evidence suggesting that the characteristics of weather extremes are changing. Thus it is crucial that climate models accurately simulate such extremes. Towards quantifying uncertainty in the extremes of precipitation, researchers examine the correspondence between a variety of data sources, including datasets from land-based and satellite measurements. They describe how results from their analysis can be used to quantify uncertainty in the extremes, and thus how model fidelity can be assessed. Enhanced Characterization of Faults and Fractures at Enhanced Geothermal Sites by CO2 Injection Coupled with Active Seismic Monitoring, Pressure-transient Testing, and Well Logging Faults and fractures in geothermal systems are difficult to image and characterize because they are nearly indistinguishable from host rock. Researchers are investigating the use of CO2 injection and production (push-pull) in faults and fractures for better characterization by active seismic, well logging, and push-pull pressure transient analysis. CO2 injected for push-pull well testing has a preference for flowing in the fault and fractures. Research results suggest that CO2 can be best imaged using time-lapse and wireline well-logging tools that measure electrical conductivity. These multiple complementary characterization approaches are being used to develop working models of fault and fracture zone characteristics relevant to energy recovery. Classification and Localization of Extreme Weather Patterns with Deep Learning Extreme weather events pose great potential risk on ecosystem, infrastructure and human health. Analyzing extreme weather and characterizing changes in extremes in simulations of future climate regimes is an important task. Researchers propose a new approach: machine learning to solve this problem. This talk will touch upon Deep Learning: the most powerful machine learning method at this point in time. Researchers will report compelling results from the successful application of Deep Learning to classify tropical cyclones, atmospheric rivers and weather front events. Can we train networks in a semi-supervised, or completely unsupervised manner? Permafrost is a crucial component of the Earth system yet has been poorly represented in Earth system models. None of the Earth system models of the CMIP5 generation included permafrost carbon dynamics, and many had poor representation of soil thermal dynamics. A number of key improvements have been made to address these shortcomings, including strategies for including permafrost carbon dynamics in models, as well as methods and datasets for benchmarking both the physical and biogeochemical components of the models. Koven will discuss recent progress and outstanding challenges that remain in understanding and quantifying the role that permafrost soils may play as feedback agents in the Earth system. With the overarching goal of understanding mineral-organic-microbe interactions on carbon and nutrient cycles, researchers are developing a model to better understand the impact of mineralogy on carbon turnover, among other things, in a floodplain site in Rifle, Colorado. Detailed characterization of the soil organic matter in sediments at the Rifle site, including radiocarbon dating and extraction and chemical characterization of mineral-bound pool of organic matter, is used to inform the modeling. Researchers will describe the development of a coupled unsaturated-saturated flow and biogeochemical reactive transport model of the Rifle site. Results suggest that soil mineralogy constitutes a dominant control over organic carbon stocks and residence times. Earth's terrestrial ecosystems absorb about one-third of all anthropogenic CO2 emissions from the atmosphere each year, greatly reducing the climate forcing those emissions would otherwise cause. This puts the size of the terrestrial carbon sink on par with the most aggressive climate mitigation measures proposed. Moreover, the land sink has been keeping pace with rising emissions and has roughly doubled over the past 40 years. But there is a fundamental lack of understanding of why the sink has been increasing and what its future trajectory could be. Better scientific understanding of the sink provides more options for policy design, enables mitigation strategies that capture co-benefits, and increases the chances that global mitigation commitments will be met. Increased subsurface fluid injection accompanying oil, gas, and geothermal exploitation and carbon dioxide sequestration, among other fluid injection applications, has increased the potential impact of injection-induced seismicity over the last few years, escalating the need to model the underlying physical processes and to assess potential seismic hazard and risks. Researchers are developing a method to assess the seismic impact of proposed fluid injection projects combining fluid flow modeling and earthquake simulation with probabilistic seismic hazard analysis. Researchers present an application of an integrated approach to hypothetical CO2 sequestration injection scenarios based on a simplified model of a faulted reservoir at King Island in the northern Sacramento Valley, California. Using Distributed Fiber Optic Sensing to Monitor Large Scale Permafrost Transitions: Preliminary Results from a Controlled Thaw Experiment In a warming world, permafrost landscapes are being rapidly transformed by thaw. The same transformations pose a threat to arctic infrastructure and can induce catastrophic failure of roads, runways, and pipelines. Scalable solutions to monitoring permafrost thaw dynamics are required to both quantitatively understand biogeochemical feedbacks as well as to protect built infrastructure from damage. Unfortunately, permafrost alteration happens over the time scale of climate change, years to decades, a decided challenge for testing new sensing technologies in a limited context. Researchers will present preliminary results from a large-scale controlled permafrost thaw experiment designed to evaluate the utility of different geophysical approaches for tracking the cause, precursors, and early phases of thaw subsidence. Precipitation extremes have impacts across a wide swath of natural and human systems. There has been quite a lot of work to understand how human activity (greenhouse gas emissions) has impacted extremes, but huge uncertainties remain. The representation of cloud processes, and resulting extreme precipitation, in climate model simulations is a huge source of uncertainty. A key uncertainty originates in the strong dependence of cloud processes on model resolution. Understanding, and ultimately improving such resolution dependence, would go a long way toward reducing uncertainty. Millennial-scale Vulnerability of the Antarctic Ice Sheet to Localized Subshelf Warm-water Forcing The Antarctic Ice Sheet (particularly the West Antarctic Ice Sheet [WAIS]) is potentially vulnerable to modes of thinning driven by climate forcing. As warm circumpolar deep water intrudes into the cavities under the ice shelves, it thins and weakens the ice shelves, compromising their ability to buttress the flow of their feeder ice streams. Both models and observations have borne out the idea that reduced buttressing can lead to rapid upstream thinning and even the onset of Marine Ice Sheet Instability. Researchers present a systematic examination of millennial-scale Antarctic vulnerability to scenarios of extreme ice-shelf melting. Enhanced Terrestrial Carbon Uptake Linked to a Recent Pause in the Growth Rate of Atmospheric CO2 The terrestrial carbon sink is increasing, yet the mechanisms responsible for its long-term enhancement, and implications for the growth rate of atmospheric CO2, remain unclear. Here, using global carbon budget estimates, ground, atmospheric and satellite observations, researchers examine the causes and consequences of the enhancement of the terrestrial carbon sink. They show that over the past century the enhanced sink is largely due to the effect of elevated CO2 on photosynthesis dominating over warming induced increases in respiration. The slowdown in global warming since the start of the 21st century is shown to have increased the sink, leading to a pause in the growth rate of atmospheric CO2. The effect of enhanced terrestrial carbon uptake on the atmospheric CO2 growth rate highlights the need to protect both existing carbon stocks and those areas where the sink is growing most rapidly. The State of Well Stimulation in California: Analyses of Data Submittals Over the past four years California has developed and instituted the most comprehensive regulation of well stimulation in the world. Analyses of the data submitted for a few hundred stimulations under the final regulations that went into effect July 2015 provides further insight into stimulation practice, which was almost entirely hydraulic fracturing during the period, as well as what regulations are working and what could be improved with regard to the required submittals. The data indicate 22 constituents are typically used in each stimulation, which is essentially the same as indicated by analysis of data sources available two years ago. However, while most of the stimulation constituents reported under the final regulations had been reported previously in other data sets regarding California, 53 constituents were reported for the first time, indicating the value of mandatory disclosure requirements. While intrinsic factors such as tree competition and soil nutrients have commonly been proposed to explain the observed patterns of tree mortality in Amazonia, researchers show in this study that windthrows, or blowdowns, act as important contributors to those observed patterns. Windthrows are more frequent in areas with no dry season, but are spatially and temporally variable across the basin. Over the next century, projected increases in extreme rainfall events may produce a dramatic increase in windthrows across the basin. Monitoring CO2 Intrusion in Shallow Aquifer Using Complex Electrical Methods and a Novel CO2 Sensitive Lidar-based Sensor While subsurface storage of CO2 in geological formations offers significant potential to mitigate atmospheric greenhouse gasses, approaches are needed to monitor the efficacy of the strategy as well as possible negative consequences, such as leakage of CO2 or brine into groundwater or release of fugitive gaseous CO2. Researchers will present results using surface electrical resistivity tomography (ERT) and a novel CO2 sensitive Lidar-based sensor to monitor a controlled CO2 release at the Zero Emission Research and Technology Center (Bozeman, Montana). The experiment suggests how a range of geophysical, remote sensing, hydrological and geochemical measurement approaches can be optimally configured to detect the distribution and explore behavior of possible CO2 leakages in distinct compartments, including groundwater and atmosphere. Climate Modeling and Analysis with Decision Makers in Mind There is a growing need for information about future climate conditions to support adaptation planning across a wide range of sectors and stakeholder communities. However, our principal tools for understanding future climate - global Earth system models - were not developed with these user needs in mind. Here, researchers highlight some of the barriers to communication and collaboration that must be overcome to improve the dialogue among researchers and climate adaptation practitioners in a meaningful way and present a vision for advancing the science of model evaluation in the context of predicting decision-relevant hydroclimate regime shifts in North America. Interactions between Cool Roofs and Urban Irrigation: Do Cooling Strategies Reduce Water Consumption in the San Francisco Bay Area? In this study, for the first time, researchers assess the overarching benefits of cooling strategies on urban water consumption. They employ a satellite-supported regional climate-modeling framework over the San Francisco Bay Area to assess the effects of cool roofs on urban irrigation. Their analysis shows that widespread incorporation of cool roofs would result in a mean daytime cooling of about 0.7° C, which in turn results in roughly 4% reduction in irrigation water. They further investigate the critical interactions between cool roofs, wind, and sea-breeze patterns as well as fog formation, in the San Francisco Bay area. Seismic hazard strongly depends on local site response, which is rarely captured by even the densest seismometer arrays. Using laser-based Rayleigh scattering with fiber optic telecommunication cables, seismic wavefield information can be recorded with a technique known as distributed acoustic sensing (DAS). Recent active and passive DAS experiments confirm trade-offs in directionality and sensitivity compared with standard seismic sensors, however the possibility of using inexpensive fiber optics and a single instrument to characterize and monitor entire earthquake-prone regions with field-scale accuracy could represent a complimentary new direction for array seismology, seismic hazard analysis, and earthquake early warning. The oceanic crust forms two thirds of the Earth's surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. Researchers present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the Lo'ihi Seamount, Hawai'i, and the East Pacific Rise (EPR). Basalt communities from Lo'ihi and the EPR show considerable metabolic and phylogenetic overlap down to the genus level despite geographic distance and slightly different seafloor basalt mineralogy. Tuesday through Friday, Berkeley Lab scientists will be available at the Earth & Environmental Sciences booth for conversations about their research. Berkeley Lab is developing 21st century approaches and scientific understanding relevant to both energy and the environment, including geothermal, nuclear waste, and geosciences, as well as fundamental research in climate studies, hydrogeology, and microbial ecology. A hallmark of the Lab's research is considering process interactions occurring within and across many Earth system compartments and scales. For a complete list of scientists, stop by booth 705.
News Article | December 1, 2016
« NREL report finds hydrogen fuel cell bus fuel economy up to 1.4x that of diesel, 1.9x CNG | Main | Toyota approves Mentor Graphics Volcano VSTAR AUTOSAR stack for ECU deployment in next-gen Toyota vehicles » The Federal Transit Administration (FTA) announced the availability of $2.75 million of funding for its Zero Emission Research Opportunity (ZERO) (FTA-2017-001-TRI). The ZERO program is to facilitate the advancement, production, and deployment of zero-emission public transportation vehicle technology and related infrastructure. FTA intends to select, and enter into cooperative agreements with, multiple (up to three) nonprofit consortia to build on past research innovation and development efforts to facilitate the deployment of zero-emission vehicles and associated advanced technology. Eligibility for future ZERO funding opportunities in fiscal years 2017-2020 will be limited to those nonprofit consortia selected under this fiscal year 2017 notice. The purpose of ZERO is to work with US industry to remove obstacles on the critical path to the wider adoption of zero emission technology in public transportation. Examples include improving charging standards for battery-electric transit vehicles, improved passenger compartment heating systems, or expanding hydrogen infrastructure. For purposes of this program, zero emission technology refers to any technology that provides a pathway to the immediate or eventual adoption of transit vehicles that produce no harmful emissions in any, and all, operating modes. Battery-electric and hydrogen fuel cell technology are typical examples. Not all pathways to zero emission vehicles have to be zero emission, but they have to be shown to be on an evolutionary pathway to zero emission. For example, hybrid technology is considered zero emission technology for the purposes of this program if it can be shown to advance the pathway to improved vehicle electrification. The projects under ZERO may address aspects of the following subject areas: Potential research partners such as transit agencies, other nonprofits, vendors, suppliers and systems integrators may work with multiple consortia. The federal cost-share of a project carried out under ZERO will not exceed 80%. Subject to FTA discretion and future appropriations, the selected organization(s) will be eligible for future funding from FY17-FY20, without further competition. Since 2008, FTA has provided more than $150 million to support the research, development and deployment of cleaner more efficient public transit vehicles. The ongoing Low and No Emission Vehicle Deployment Program has proven the interest of transit agencies to procure and operate highly innovative and efficient models, including battery electric and hydrogen fuel cell buses. In implementing ZERO, FTA will use a cooperative research model similar to FTA’s National Fuel Cell Bus Program. Under this model, research and demonstration projects are defined and conducted by pre-selected non-profit consortia that, under FTA direction, assemble and manage project teams. Teams, comprised of transit agencies, vendors, suppliers, and others, will introduce an enhanced level of research management, program continuity, and flexibility to federally funded transit research. Through ZERO, FTA seeks to refine this research model and create a research environment that results in greater industry involvement and more innovative and successful projects.
Serov A.,University of New Mexico |
Artyushkova K.,University of New Mexico |
Niangar E.,Zero Emission Research |
Wang C.,Zero Emission Research |
And 6 more authors.
Nano Energy | Year: 2015
A highly active and durable non-platinum group metal (non-PGM) electrocatalyst was synthesized at high temperature from a catalyst precursor involving a ferrous iron salt and a nitrogen-containing charge-transfer salt as a precursor to form a nano-structured catalyst with performance level that makes it suitable for automotive applications. Such precursors have not been previously investigated for non-PGM catalysts. The synthesized material belongs to the class of metal-nitrogen-carbon catalysts and possesses an open-frame structure controlled by the silica-templating synthesis method. Thorough characterization using X-ray photoelectron, Mössbauer and in situ X-ray absorption spectroscopies demonstrates the successful formation of FeNxCy moieties that are active towards the oxygen reduction reaction. We report high kinetic current densities and high power performance in both rotating disk electrode and membrane electrode assembly studies. This Fe-N-C catalyst, jointly investigated by academic and industry partners, has shown high durability under different protocols, including that defined by the US Department of Energy Durability Working Group and Nissan[U+05F3]s load cycling protocol. In summary, the present Fe-N-C catalyst is highly active and durable, making it a viable alternative to Pt-based electrocatalysts for automobile fuel cell applications. © 2015 Elsevier Ltd.
Brodt M.,Vanderbilt University |
Wycisk R.,Vanderbilt University |
Pintauro P.,Vanderbilt University |
Han T.,Zero Emission Research |
And 2 more authors.
ECS Transactions | Year: 2013
Nanofiber electrodes prepared with three different commercial Pt/C catalysts and 1100 EW Nafion® binder were fabricated by electrospinning. The electrodes were further processed into membrane-electrode- assemblies (MEAs) using Nafion 211 as the membrane material. MEAs were evaluated for catalyst activity and power output in a hydrogen/air fuel cell at 80°C. Tanaka Kikinzoku Kogyo (TKK) TEC10E50E (46.1% Pt on Ketjen Black) was more electrochemically active and produced slightly more power than its heat-treated counterpart, TKK TEC10E50E-HT (50.5% Pt on Ketjen Black), and Johnson Matthey HiSpec 4000 catalyst (40% Pt on Vulcan carbon). The nanofiber cathodes were compared to MEAs with standard non-structured gas diffusion electrodes (GDEs) containing the same catalysts, and in all cases, the electrospun fibers generated more power. For example, with a Pt loading of 0.10 mg/cm2, the electrospun TKK TEC10E50E generated 470 mW/cm2 at a 0.65 V vs. 349 mW/cm2 for the GDEbased MEA, an improvement of 35%. The effect of nanofiber composition (the ratio of Pt/C to Nafion) and the effect of fiber diameter on power output were also investigated. In general, such changes had a little or no impact on performance and all the electrospun mats tested yielded MEAs that produced very high power. © The Electrochemical Society.
Brodt M.,Vanderbilt University |
Han T.,Zero Emission Research |
Dale N.,Zero Emission Research |
Niangar E.,Zero Emission Research |
And 2 more authors.
Journal of the Electrochemical Society | Year: 2015
A series of electrospun nanofiber mat electrodes with two different commercial Pt/C catalysts and a binder of Nafion and poly(acrylic acid) were fabricated and evaluated. The electrodes were assembled into membrane-electrode-assemblies (MEAs) using Nafion 211 as the membrane. Variations in catalyst type, nanofiber composition (the ratio of Pt/C to Nafion), and fiber diameter had little or no impact on hydrogen/air fuel cell power output. 25 cm2 nanofiber and sprayed gas diffusion electrode MEAs were compared in terms of beginning of life (BoL) and end of life (EoL) performance after automotive-specific load cycling (Pt dissolution) and start-stop cycling (carbon corrosion) cathode durability protocols. Nanofiber electrode MEAs (0.10 mg/cm2 Pt loading for the anode and cathode) were clearly superior to sprayed MEAs; they produced more power at BoL and maintained a higher percentage of their power after the carbon corrosion durability protocol, resulting in much higher EoL fuel cell performance. On the other hand, there was no effect of electrode morphology on MEA durability for the Pt dissolution test. The higher MEA power output after carbon corrosion with electrospun electrodes is attributed to better oxygen and water transport within the nanofiber electrode and a higher electrochemical surface area for the fiber cathode. © The Author(s) 2014.