Environmental Science and Technology
Air Quality and Climate Modeling
Energy policies and related technological development can impact energy markets, air quality, human health, regional meteorology, and climate. Conversely, regional meteorological trends, climate, and air quality can impact solar and wind power generation.
We examine both of these impact pathways through the use of state-of-the-art atmospheric and urban modeling tools, and the analysis of satellite, surface, and other types of observational environmental data. We collaborate with industry and academic partners to address the most pressing and applicable problems.
Ambient air pollution is a result of interactions of natural and anthropogenic emissions with meteorology through chemical transport processes with the atmosphere, vegetation, and building surfaces. We develop and apply air quality modeling and sensitivity analysis tools to investigate:
- Source-receptor relationships
- Meteorology-chemistry interactions
- Single and multiple pollutant control strategies
- Urban air pollution and chemical hazard mitigation
- Effective air pollution mitigation strategies for specific geographic regions, energy sources, and technologies
We also develop and apply meteorological modeling tools and analyses to investigate what drives variability in resource availability (e.g. wind speed, or surface insolation) in order to determine how best to utilize renewable resources.
Scientists use and develop a wide range of models, depending on the spatial and temporal requirements of the research. These include meso-scale models, urban-scale large-eddy simulations, and regulatory puff models.
Greenhouse Gas Measurements and Modeling
The combination of greenhouse gas (GHG) measurements and modeling allows us to better understand the sources of GHGs from anthropogenic sources, including short-lived climate pollutants, and ultimately validate the estimation methods and inventories used to make policy and model future climate impacts. The California Greenhouse Gas Emissions Measurement Project (CALGEM) currently comprises a full-scope combination of field sites, measurement instrumentation, and numerical modeling as a user facility for quantification of anthropogenic GHG emissions of individual facilities to air basin scales.
- Long-term field sites outside major urban centers in Central (San Francisco and Sacramento) and Southern California (San Bernardino)
- Continuous full-suite GHG (CO2, CH4, N2O, CO), and/or periodic flask (e.g., 14CO2, 13CO2, 13CH4) measurements
- Mobile field measurement capabilities include instrumented aircraft, balloon borne full column GHG sampling, and mobile plume integrator survey (MPI) instrument
- Laboratory measurements of all major GHGs (CO2, CH4, N2O, CO) and selected stable isotopes (13CO2, 13CH4) for secondary reference gas calibration
- Spatiotemporally-explicit bottom-up estimates for California methane emissions
- Atmospheric transport simulation using the NCAR Weather Research Forecasts (WRF) at 1 km resolution in domains over California
- Stochastic Time Inverted Lagrangian Transport (STILT) model calculations receptor footprints
- Inverse emissions estimation capabilities including linear and hierarchical Bayesian, as well as geo-statistical inverse models
- Evaluation of predicted transport using wind velocity and boundary layer depth and turbulence data from using network data from radar wind profilers
Air Pollution Science and Technology
Air pollution is the leading environmental contributor to diseases that cause millions of premature deaths around the world each year. Our team researches cutting-edge clean air technologies, develops novel air pollution sensors, pollutant transport and transformation, and evaluates in-use pollutant emissions and controls. We focus on a range of pollutants and sources. Areas of focus include:
- Leading research to measure the in-use performance and durability of diesel particle filters and selective catalytic reduction systems on heavy-duty diesel truck emissions of gaseous and particulate pollutants
- Developing new sensing technologies for methods for measuring atmospheric particulate matter and black carbon, including novel applications of low cost sensors for distributed monitoring to learn how pollutants vary in space and with time in residential communities
- Quantifying emissions of greenhouse gases, odorous compounds, and other air pollutants associated with anaerobic digestion of organic municipal solid waste to produce biogas, conversion to electricity, and composting processes
- Examining how black and brown carbon from wildfires, residential fireplaces, and other sources interact with sunlight on surfaces including snow and rooftops
- Developing operational tools to predict coupled urban and indoor transport of airborne hazardous materials, to support real-time decision-makers and pre-event planners
- Developing a virtual simulation environment by coupling a Large Eddy Simulation atmospheric transport and dispersion model to building interior models. The goal is to produce virtual datasets of airborne material dispersion in urban areas, in order to evaluate operational tools and train analysts
- Evaluating how conventional (combustion) cigarettes and innovative nicotine-delivery devices (such as electronic cigarettes) contribute to poor indoor environmental quality
- Understanding chemical transformations of surface-bound tobacco contaminants (“thirdhand smoke”) leading to long-term exposures via inhalation and dermal contact
- Exploring the potential of photocatalytic self-cleaning and de-polluting building envelope surfaces to maintain high albedos and contribute to scrubbing nitrogen oxides and other pollutants from urban atmospheres
- Evaluating air cleaning technologies for buildings and the aircraft cabin