Article
Engineering, Environmental
Katelyn A. Yu, Meng Li, Colin Harkins, Jian He, Qindan Zhu, Bert Verreyken, Rebecca H. Schwantes, Ronald C. Cohen, Brian C. Mcdonald, Robert A. Harley
Summary: The reduction in anthropogenic NOx emissions from motor vehicles due to emission control technologies and policies is significant but uncertain. This study evaluates a fuel-based emission inventory for southern California, finding that on-road vehicles are the main source of NOx emissions in the South Coast Air Basin. The fuel-based inventory provides different estimates of NOx emissions for different vehicle types compared to the planning inventory.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Environmental Sciences
Vineet Yadav, Kristal Verhulst, Riley Duren, Andrew Thorpe, Jooil Kim, Ralph Keeling, Ray Weiss, Dan Cusworth, Marikate Mountain, Charles Miller, James Whetstone
Summary: The Los Angeles basin accounted for 20% of California's methane emissions in 2016, emphasizing the need to reduce these emissions and meet greenhouse gas reduction targets. However, mitigation efforts face challenges due to the presence of diverse methane sources such as oil and gas production fields, refineries, landfills, wastewater treatment facilities, and natural gas infrastructure. This study analyzes the temporal variability in surface concentrations from February 2015 to April 2022 and detects a declining trend in methane emissions. Through inverse modeling, the study quantifies a 15 Gg (approximately 7%) reduction in methane emissions in the LA basin over a five-year period from January 2015 to May 2020.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Xiaoxiao Feng, Xiaole Zhang, Jing Wang
Summary: This study developed a method to update the SO2 emission inventory in Chongqing, which is useful for evaluating the SO2 pollution and designing effective emission reduction policies. The updated emission inventory was estimated by integrating the a priori knowledge of the baseline emissions and the current observations using Bayesian inference. The adjustment of the emissions improved the accuracy in predicting SO2 concentrations with the developed method.
ATMOSPHERIC ENVIRONMENT
(2023)
Article
Engineering, Environmental
Eva Y. Pfannerstill, Caleb Arata, Qindan Zhu, Benjamin C. Schulze, Roy Woods, Colin Harkins, Rebecca H. Schwantes, Brian C. Mcdonald, John H. Seinfeld, Anthony Bucholtz, Ronald C. Cohen, Allen H. Goldstein
Summary: Los Angeles is a major hotspot for air pollution, particularly ozone and particulate matter. Despite reductions in vehicular emissions, the improvement of ozone and PM2.5 levels in the region has been limited. Measurement of VOCs and comparison with emission inventories reveal discrepancies in the amount and distribution of observed VOC emissions in Los Angeles.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Kenan Li, John P. Wilson
Summary: Superblocks can transform urban areas into pedestrian-centric neighborhoods, providing significant health benefits. We developed a framework to build a Superblocks Model for the City of LA and assess its predicted health benefits. Transforming 5-10% of residential areas into superblocks resulted in significant reductions in hospital admissions and economic savings. The findings help stakeholders determine the balance between reduced car traffic and improved health outcomes.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Marine
Guangnian Xiao, Tian Wang, Xinqiang Chen, Lizhen Zhou
Summary: The role of the shipping industry in international logistics has become increasingly important, but it has also brought about environmental problems. This study analyzed the ship pollutant emissions in the ports of Los Angeles and Long Beach based on data from 2020, and found that there is a significant difference in emissions based on ship types and sailing states. Additionally, the effectiveness of ECA policies in controlling pollutant emissions varies.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Dustin Roten, John C. Lin, Saswati Das, Eric A. Kort
Summary: This study investigates the potential of using Snapshot Area Map observations from NASA's OCO-3 instrument to disaggregate sector-specific emissions of carbon dioxide (CO2). Results demonstrate that space-based observations of atmospheric CO2 are capable of accurately disentangling sector-specific CO2 fluxes, paving the way for monitoring the effects of carbon reduction policies and operational carbon monitoring systems.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Nasrin Mostafavi Pak, Sajjan Heerah, Junhua Zhang, Elton Chan, Doug Worthy, Felix Vogel, Debra Wunch
Summary: The study presents the Facility Level and Area Methane (CH4) Emissions inventory for the Greater Toronto Area (FLAME-GTA), estimating total emissions of CH4 to be about 86 ± 38 Gg/yr. Using a Lagrangian transport model, atmospheric mixing ratios based on different emission inventories are predicted and compared with in situ measurements. Results indicate the need for a more extensive measurement network and an improved atmospheric transport modeling effort for further evaluation of emission inventories.
ATMOSPHERIC ENVIRONMENT
(2021)
Article
Green & Sustainable Science & Technology
Brett F. Sanders, Jochen E. Schubert, Daniel T. Kahl, Katharine J. Mach, David Brady, Amir AghaKouchak, Fonna Forman, Richard A. Matthew, Nicola Ulibarri, Steven J. Davis
Summary: Flood risks in the United States have historically been underestimated, particularly with respect to human well-being and within low-wealth and marginalized communities. In Los Angeles, flood risks are disproportionately high for historically disadvantaged populations and communities already facing social inequities.
NATURE SUSTAINABILITY
(2023)
Article
Engineering, Environmental
Long Ta Bui, Phong Hoang Nguyen, Duyen Chau My Nguyen
Summary: This study developed a platform using a modelling and web technology approach to estimate methane emissions from landfills. The EnLandFill software was applied to quantify CH4 emissions and evaluate the range and level of impacts of landfill emissions.
Article
Engineering, Environmental
Michael Jorgen Hansen, Lise Bonne Guldberg, Sasha Daniel Hafner, Anders Feilberg, Frederik Rask Dalby
Summary: Reducing methane emissions from livestock slurry is crucial in mitigating global warming. Three strategies, including slurry funnels, slurry trays, and weekly flushing, were found to significantly reduce slurry methane emission by 89%, 81%, and 53% respectively. However, there is a risk of increased emissions from outside storage, negating the methane reductions from pig houses, which can be countered by combining removal strategies with anaerobic digestion pre-storage or storage mitigation technologies.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Geography
Richard Kirk
Summary: In this article, the authors introduce "Dracula urbanism" as a framework for understanding hidden dynamics in advanced capitalist cities engaged in smart city initiatives. The author argues that the concept of Dracula urbanism can be applied to urban redevelopment beyond real estate and smart cities, shedding light on issues such as gentrification and urban exclusion. The article emphasizes the importance of the local context in the multi-scalar imagination of Dracula urbanism and criticizes the notion of centerless and unbounded smart cities, revealing inter-urban competition and border-defined discourses.
Article
Geochemistry & Geophysics
Jack B. Muir, Robert W. Clayton, Victor C. Tsai, Quentin Brissaud
Summary: The proliferation of dense arrays improves the imaging of geological structures. However, integrating local high-resolution tomography with existing regional models remains challenging. Researchers developed a framework based on the level-set method to update regional models using local data, which is significant for seismic hazard assessment.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Environmental Sciences
David T. Allen, Felipe J. Cardoso-Saldana, Yosuke Kimura, Qining Chen, Zhanhong Xiang, Daniel Zimmerle, Clay Bell, Chris Lute, Jerry Duggan, Matthew Harrison
Summary: This study presents a tool for estimating routine emissions from oil and gas well sites at multiple time scales. It emphasizes the importance of developing detailed emission inventories that incorporate operational data when comparing measurements to routine emissions.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Multidisciplinary Sciences
Lei Yang, Xin Liu, Gregory C. Beroza
Summary: This study revisits the widespread deep seismicity in the upper mantle in Long Beach, California, utilizing a dense nodal seismic array to detect candidate events and develop a reliable imaging threshold. The results show that most small events detected at depths greater than 20 kilometers in the upper mantle fall below the reliability threshold, while a modest number of small, shallow events in the crust appear to align with the active Newport-Inglewood Fault.
Article
Engineering, Environmental
Pamela S. Rickly, Matthew M. Coggon, Kenneth C. Aikin, Raul J. Alvarez II, Sunil Baidar, Jessica B. Gilman, Georgios I. Gkatzelis, Colin Harkins, Jian He, Aaron Lamplugh, Andrew O. Langford, Brian C. McDonald, Jeff Peischl, Michael A. Robinson, Andrew W. Rollins, Rebecca H. Schwantes, Christoph J. Senff, Carsten Warneke, Steven S. Brown
Summary: Increasing trends in biomass burning emissions significantly impact air quality in North America. The transport of smoke from local and long-range fires has been found to increase the mixing ratios of ozone (O3) in urban areas. This is primarily due to the transport of pyrogenic volatile organic compounds (PVOCs) and the influence of O3 produced within the smoke. Detailed chemical measurements have shown that both local and long-range smoke periods lead to increases in carbon monoxide, background O3, OH reactivity, and total VOCs, while the NOx mixing ratios remain constant. Box-model calculations indicate that local O3 production is in the NOx-sensitive regime, with PVOCs substantially increasing O3 production in the transition and NOx-saturated regimes.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Environmental Sciences
A. K. Thorpe, E. A. Kort, D. H. Cusworth, A. K. Ayasse, B. D. Bue, V Yadav, D. R. Thompson, C. Frankenberg, J. Herner, M. Falk, R. O. Green, C. E. Miller, R. M. Duren
Summary: In the summer of 2020, the AVIRIS-NG airborne imaging spectrometer conducted surveys in California's Southern San Joaquin Valley and the South Bay to identify and analyze anthropogenic methane emissions. The results showed a decrease in CH4 emissions from the energy and oil & natural gas sectors, with variations observed across different facilities and sectors. This study not only assessed the impact of COVID-19 on CH4 emissions but also highlighted the potential of remote sensing technology in quantifying emissions at a sector and facility level.
ENVIRONMENTAL RESEARCH COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Alan M. Gorchov Negron, Eric A. Kort, Yuanlei Chen, Adam R. Brandt, Mackenzie L. Smith, Genevieve Plant, Alana K. Ayasse, Stefan Schwietzke, Daniel Zavala-Araiza, Catherine Hausman, Angel F. Adames-Corraliza
Summary: The Gulf of Mexico is the largest offshore fossil fuel production basin in the United States. This study estimates the climate impact of current field operations by collecting airborne observations and combining them with previous surveys and inventories. The findings show high methane emissions exceeding inventories, resulting in an elevated carbon intensity (CI) of the basin. Shallow waters exhibit an extraordinarily high CI primarily driven by methane emissions, indicating the outsized climate impact of current production in these areas.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Multidisciplinary Sciences
Evan D. Sherwin, Jeffrey S. Rutherford, Yuanlei Chen, Sam Aminfard, Eric A. Kort, Robert B. Jackson, Adam R. Brandt
Summary: Satellites are considered a useful tool for identifying large greenhouse gas point sources, but independent verification is needed for acceptance. The first single-blind controlled methane release testing of satellite-based detection and quantification was conducted, with five teams analyzing data from one to five satellites. The teams correctly identified 71% of all emissions, ranging from 0.20 to 7.2 metric tons per hour.
SCIENTIFIC REPORTS
(2023)
Article
Meteorology & Atmospheric Sciences
Emily G. Yang, Eric A. Kort, Lesley E. Ott, Tomohiro Oda, John C. Lin
Summary: Since a majority of CO2 emissions from fossil fuels come from cities, it is important to use novel techniques to utilize satellite observations of CO2 and proxy species to control urban CO2. This study aims to establish the relationship between satellite observations of CO2 and the proxy species of NO2 and estimate CO2 emissions based on NO2 data. The method was tested in Buenos Aires, Melbourne, and Mexico City and proved to be viable throughout the year. This method provides a valuable observational constraint on urban CO2 emissions, with comparable monthly urban CO2 emissions estimates to inventory estimates.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Daniel E. Huber, Allison L. Steiner, Eric A. Kort
Summary: As fossil fuel combustion decreases, the contribution of NOx emissions from managed and unmanaged soils (S-NOx) is increasing. While the Berkeley Dalhousie Soil NOx Parameterization (BDSNP) is commonly used to represent S-NOx, it relies on static relationships between soil moisture and S-NOx, which do not capture the dynamic nature of emissions. In this study, the BDSNP is updated to incorporate a dynamic S-NOx response to soil moisture, resulting in improved representation of S-NOx and reduced sensitivity to input soil moisture data.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Raj. M. M. Lal, Eric. A. A. Kort
Summary: Cities around the world have introduced initiatives to reduce CO2 emissions. Atmospheric observations can provide evaluation and assessment of these initiatives by quantifying emissions, considering local sources and sinks. The relative importance of the urban biosphere, which can act as both a source (respiration) and sink (photosynthesis) of CO2, has previously been suggested to strongly impact urban CO2 measurements, confounding the ability to use observations to study fossil emissions.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Engineering, Environmental
Kanako Sekimoto, Matthew M. Coggon, Georgios I. Gkatzelis, Chelsea E. Stockwell, Jeff Peischl, Amber J. Soja, Carsten Warneke
Summary: This study finds that emissions of volatile organic compounds (VOCs) from biomass burning, which have impacts on air quality and climate, can be characterized by high- and low-temperature pyrolysis VOC profiles. The variability in VOC speciation is mainly influenced by combustion conditions rather than fuel type. The findings are based on measurements of VOCs obtained during the FIREX-AQ project in 2019 using a proton-transfer reaction time-of-flight mass spectrometer.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Kanako Sekimoto, Matthew M. Coggon, Georgios I. Gkatzelis, Chelsea E. Stockwell, Jeff Peischl, Amber J. Soja, Carsten Warneke
Summary: Laboratory studies have shown that biomass burning emissions of volatile organic compounds (VOCs) are mainly affected by combustion conditions rather than fuel type. In this study, ambient smoke emissions from wildfires in the western US were analyzed using positive matrix factorization (PMF) and measured with a mass spectrometer. The results showed that the variability in VOC emissions can be described by high- and low-temperature pyrolysis VOC profiles, which is consistent with previous laboratory findings.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Environmental Sciences
Jeff Peischl, Kenneth C. Aikin, Brian C. McDonald, Colin Harkins, Ann M. Middlebrook, Andrew O. Langford, Owen R. Cooper, Kai -Lan Chang, Steven S. Brown
Summary: The COVID-19 pandemic led to lockdowns in the United States, resulting in decreased on-road emissions and lower concentrations of pollutants such as nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and particulate matter (PM2.5). The concentrations of these pollutants generally decreased in 9 U.S. cities during late March and early April, and decadal trends showed decreases in the summer months. The analysis also revealed anomalous increases in pollutants in western U.S. cities during late summer, attributed to wildfire emissions.
ELEMENTA-SCIENCE OF THE ANTHROPOCENE
(2023)
Article
Environmental Sciences
Hao Guo, Clare M. Flynn, Michael J. Prather, Sarah A. Strode, Stephen D. Steenrod, Louisa Emmons, Forrest Lacey, Jean-Francois Lamarque, Arlene M. Fiore, Gus Correa, Lee T. Murray, Glenn M. Wolfe, Jason M. St. Clair, Michelle Kim, John Crounse, Glenn Diskin, Joshua DiGangi, Bruce C. Daube, Roisin Commane, Kathryn McKain, Jeff Peischl, Thomas B. Ryerson, Chelsea Thompson, Thomas F. Hanisco, Donald Blake, Nicola J. Blake, Eric C. Apel, Rebecca S. Hornbrook, James W. Elkins, Eric J. Hintsa, Fred L. Moore, Steven C. Wofsy
Summary: The NASA ATom mission collected in situ measurements of key reactive species in air parcels over the Pacific and Atlantic oceans. The study found that a large portion of the total reactivity is concentrated in a fraction of all air parcels, supporting previous model-only studies. The results also showed that current global chemistry models can capture much of the heterogeneity in tropospheric chemistry.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Cynthia H. Whaley, Kathy S. Law, Jens Liengaard Hjorth, Henrik Skov, Stephen R. Arnold, Joakim Langner, Jakob Boyd Pernov, Garance Bergeron, Ilann Bourgeois, Jesper H. Christensen, Rong-You Chien, Makoto Deushi, Xinyi Dong, Peter Effertz, Gregory Faluvegi, Mark Flanner, Joshua S. Fu, Michael Gauss, Greg Huey, Ulas Im, Rigel Kivi, Louis Marelle, Tatsuo Onishi, Naga Oshima, Irina Petropavlovskikh, Jeff Peischl, David A. Plummer, Luca Pozzoli, Jean-Christophe Raut, Tom Ryerson, Ragnhild Skeie, Sverre Solberg, Manu A. Thomas, Chelsea Thompson, Kostas Tsigaridis, Svetlana Tsyro, Steven T. Turnock, Knut von Salzen, David W. Tarasick
Summary: This study summarizes recent research on the observations and modeling of tropospheric ozone in the Arctic, revealing significant differences in the seasonal cycles of surface ozone at different locations. The 12 state-of-the-art models used in this study lack the necessary surface halogen chemistry to accurately simulate coastal Arctic surface ozone depletion. The multi-model median underestimates Arctic surface ozone by 5% to 15% depending on the location, and there is a wide variability among the models.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Alkuin M. Koenig, Olivier Magand, Bert Verreyken, Jerome Brioude, Crist Amelynck, Niels Schoon, Aurelie Colomb, Beatriz Ferreira Araujo, Michel Ramonet, Mahesh K. Sha, Jean-Pierre Cammas, Jeroen E. Sonke, Aurelien Dommergue
Summary: This article investigates atmospheric mercury concentrations and redox reactions in the lower free troposphere, and finds a lack of continuous monitoring stations in the Southern Hemisphere. By analyzing data from the Maido mountain observatory for 9 months, it identifies significant diurnal and seasonal variations in atmospheric elemental mercury.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Viral Shah, Daniel J. Jacob, Ruijun Dang, Lok N. Lamsal, Sarah A. Strode, Stephen D. Steenrod, K. Folkert Boersma, Sebastian D. Eastham, Thibaud M. Fritz, Chelsea Thompson, Jeff Peischl, Ilann Bourgeois, Ilana B. Pollack, Benjamin A. Nault, Ronald C. Cohen, Pedro Campuzano-Jost, Jose L. Jimenez, Simone T. Andersen, Lucy J. Carpenter, Tomas Sherwen, Mat J. Evans
Summary: Satellite-based retrievals of tropospheric NO2 columns are widely used to infer NOx emissions. These retrievals rely on model information for the vertical distribution of NO2. Free tropospheric background above 2 km is important for these retrievals and has a significant impact on tropospheric OH and ozone concentrations.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Christopher Hoang, Olivier Magand, Jerome Brioude, Andrea Dimuro, Christophe Brunet, Claudine Ah-Peng, Yann Bertrand, Aurelien Dommergue, Ying Duan Lei, Frank Wania
Summary: Reliably recording low GEM concentrations in remote regions is challenging. In this study, passive air samplers were deployed in extreme environments for up to three years. The size of the sequestered mercury and contamination of field blank samples influenced the reliable recording of GEM concentrations. Longer deployment periods and storage in sealed glass jars were found to be effective in reducing contamination. However, sampling in Antarctica was compromised due to extreme temperatures and material failure.
ENVIRONMENTAL SCIENCE-ATMOSPHERES
(2023)
