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
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
Multidisciplinary Sciences
Xin Liu, Gregory C. Beroza, Lei Yang, William L. Ellsworth
Summary: Seismic attenuation tomography in the Los Angeles basin provides important constraints on wave propagation and structural information, particularly effective for analyzing earthquake faults.
Article
Meteorology & Atmospheric Sciences
Si-Wan Kim, Brian C. McDonald, Seunghwan Seo, Kyoung-Min Kim, Michael Trainer
Summary: Ozone in the urban atmosphere, mainly derived from fossil fuel combustions and volatile chemical products, has a detrimental impact on the ecosystem and human health. The Los Angeles Basin, a classic example of an urban region with long-standing ozone pollution, has seen declines in ozone and precursor concentrations over the past half century due to pollution controls. However, since 2000, the ozone design value has not been able to fully reach the air quality standard set by the EPA. Our study reveals that the area is undergoing a significant transition in photochemistry towards lower ozone concentrations and suggests that further reductions of NOx emissions can lead to continued improvement of ozone pollution.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Multidisciplinary Sciences
Sunyoung Park, Changsoo Shin, Younglib Kim, Robert W. Clayton
Summary: Studying seismic wave propagation through complex media is crucial for understanding the behavior of earthquakes. This research utilized 3D printing to create physical models of geological structures and conducted lab-scale seismic experiments. The results revealed insights into wave propagation in sedimentary basins, challenging conventional views on the amplification of ground motion.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Environmental
Clara M. Nussbaumer, Ronald C. Cohen
Summary: Air quality policy in the Los Angeles megacity has significantly reduced aerosol concentrations and high aerosol event frequency over the last 20 years. Emission control has been effective in decreasing temperature-independent sources, making aerosol response to temperature a dominant feature of high aerosol events. Organics in aerosols increase with temperature, with certain molecules explaining the observed temperature dependence of PM 2.5.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
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
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
Engineering, Environmental
Vahid Jalali Farahani, Abdulmalik Altuwayjiri, Sina Taghvaee, Constantinos Sioutas
Summary: This study estimated the emission factors of PM10 and its chemical constituents from various sources on two freeways in the Los Angeles basin. The results showed that non-tailpipe emissions, particularly from heavy-duty vehicles on the I-710 freeway, had higher PM10 and metal element emission factors compared to the I-110 freeway. The study also found that road dust resuspension contributed twice as much non-tailpipe PM10 as tire and brake wear.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Geochemistry & Geophysics
Zhe Jia, Robert W. Clayton
Summary: This study investigates the shallow shear wave velocity structure of the Los Angeles Basin in southern California using ambient noise correlations, observing clear fundamental mode and first overtone Rayleigh waves. Through tomography, group velocity maps were obtained and a 3D shear wave velocity model was derived, revealing finer resolution of shallow velocity structure heterogeneities compared to existing models. The model accurately captures the presence of the Newport-Inglewood fault with a high velocity belt and provides more precise constraints on local ground motion predictions.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Valeria Villa, Yida Li, Robert W. Clayton, Patricia Persaud
Summary: The San Gabriel, Chino, and San Bernardino sedimentary basins in Southern California amplify earthquake ground motions and prolong shaking duration. A three-dimensional basement map of the basins is obtained by integrating gravity and seismic measurements, providing accurate ground-shaking models. The study demonstrates the importance of gravity data in interpreting the sediment-basement interface.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
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
Chemistry, Multidisciplinary
Paul Van Rooy, Afsara Tasnia, Barbara Barletta, Reina Buenconsejo, John D. Crounse, Christopher M. Kenseth, Simone Meinardi, Sara Murphy, Harrison Parker, Benjamin Schulze, John H. Seinfeld, Paul O. Wennberg, Donald R. Blake, Kelley C. Barsanti
Summary: During the COVID-19 pandemic in 2020, monitoring of volatile organic compounds in the Los Angeles Basin showed stable emission ratios relative to acetylene but a decrease in emission ratios relative to carbon monoxide. The observed results indicate a shift in source contributions, suggesting an increase in estimated OH exposure by 70-120% compared to 2010.
ACS EARTH AND SPACE CHEMISTRY
(2021)
Article
Environmental Sciences
I. Stanimirova, David Q. Rich, Armistead G. Russell, P. K. Hopke
Summary: This study evaluates the effects of air quality control policies implemented in California from 2005 to 2019 on air quality at two sampling sites in the Los Angeles Basin. The findings indicate a significant decrease in contributions of secondary nitrate and secondary sulfate to ambient PM2.5 concentrations due to the implementation of California programs. The study also identifies residual oil and traffic as the main sources of fuel combustion in the Los Angeles area, while separate gasoline and diesel vehicle sources were identified in Rubidoux. Additionally, wildfires, mineral dust transport, and storms were found to contribute to poor air quality.
ENVIRONMENTAL POLLUTION
(2024)
Article
Environmental Sciences
Kang Zhu, Xing Zhang, Qian Sun, Hai Wang, Jun Hu
Summary: Excessive extraction and recharge of groundwater cause long-term land subsidence in the Santa Ana basin, Los Angeles, USA, posing a danger to infrastructure and human lives. Traditional parameter estimation methods have limited understanding of the regional spatiotemporal characteristics. In this study, multitemporal InSAR data and independent component analysis (ICA) method were used to analyze the deformation patterns in the basin. The results showed a correlation between seasonal deformation and groundwater level, with a quick response to groundwater changes.
Article
Engineering, Chemical
Derek J. Price, Mary Kacarab, David R. Cocker, Kathleen L. Purvis-Roberts, Philip J. Silva
AEROSOL SCIENCE AND TECHNOLOGY
(2016)
Article
Environmental Sciences
Xiaochen Tang, Derek Price, Eric Praske, Su Anne Lee, Morgan A. Shattuck, Kathleen Purvis-Roberts, Philip J. Silva, Akua Asa-Awuku, David R. Cocker
ATMOSPHERIC ENVIRONMENT
(2013)
Article
Environmental Sciences
Derek J. Price, Christopher H. Clark, Xiaochen Tang, David R. Cocker, Kathleen L. Purvis-Roberts, Philip J. Silva
ATMOSPHERIC ENVIRONMENT
(2014)
Article
Biochemical Research Methods
Mark E. Erupe, Allegra Liberman-Martin, Philip J. Silva, Quentin G. J. Malloy, Naomi Yonis, David R. Cocker, Kathleen L. Purvis-Roberts
JOURNAL OF CHROMATOGRAPHY A
(2010)
Article
Genetics & Heredity
Bashar Alhoch, Alan Chen, Elaine Chan, Asmaa Elkabti, Sasha Farina, Catherine Gilbert, Jean Kang, Bradley King, Karen Leung, Julia Levy, Elizabeth Martin, Benjamin Mazer, Sara McKinney, Alexandra Moyzis, Margaret Nurimba, Michelle Ozaki, Kathleen Purvis-Roberts, Joshua Marc Rothman, Shravya Raju, Cynthia Selassie, Oliver Smith, Julia Ticus, Gretchen Edwalds-Gilbert, M. Cristina Negritto, Ruye Wang, Zhaohua Tang
G3-GENES GENOMES GENETICS
(2019)
Article
Green & Sustainable Science & Technology
Norasikin Ahmad Ludin, Nurfarhana Alyssa Ahmad Affandi, Kathleen Purvis-Roberts, Azah Ahmad, Mohd Adib Ibrahim, Kamaruzzaman Sopian, Sufian Jusoh
Summary: This study analyzes the technical and economic feasibility of three types of solar photovoltaic renewable energy systems in tropical climate regions, finding that grid-connected roof-mounted systems achieve the lowest levelized cost of energy compared to other types of installations.
Article
Environmental Sciences
Paul Van Rooy, Kathleen L. Purvis-Roberts, Philip J. Silva, Matthew J. Nee, David Cocker
Summary: This study investigated the oxidation mechanism and aerosol forming potential of DMS and DMDS under dry conditions in an environmental chamber. Results showed that with relatively low initial NOx concentrations, O(3P) dominated the oxidation of reduced sulfur precursor and resulted in aerosol mass yields of greater than 40%.
ATMOSPHERIC ENVIRONMENT
(2021)
Article
Environmental Sciences
Paul Van Rooy, Ryan Drover, Tanner Cress, Cara Michael, Kathleen L. Purvis-Roberts, Philip J. Silva, Matthew J. Nee, David Cocker
Summary: The study investigates the mechanisms and factors influencing the formation of particulate MSA through oxidation experiments on dimethylsulfide and dimethyldisulfide. Results show that substantial water vapor and the presence of NOx are essential for MSA formation, with nitrate radical oxidation potentially playing a significant role in ambient MSA levels. Further research is needed to better understand the impacts of reduced sulfur compounds on health and climate.
ATMOSPHERIC ENVIRONMENT
(2021)
Article
Green & Sustainable Science & Technology
M. M. Junedi, N. A. Ludin, P. R. Kathleen, N. H. Hamid, J. Hasila, N. A. Ahmad Affandi
Summary: Land utilisation by the solar energy industry and other sectors has become competitive, making space optimisation essential. This article discusses the configurations of integrated photovoltaic systems, including PV-wind, building integrated- or applied- PV, and agrophotovoltaic systems. These systems differ in their electricity generation methods but all aim to reduce emissions and provide economic benefits.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Green & Sustainable Science & Technology
Nurfarhana Alyssa Ahmad Affandi, Norasikin Ahmad Ludin, Mirratul Mukminah Junedi, Kathleen Purvis-Roberts
Summary: The number of fuelling stations continues to grow with increasing population and demand. The concept of low carbon building for cities and communities has prompted a re-evaluation of fuel station provision, using solar photovoltaics as a safe and mature renewable system. This study examines the emissions of a fuel retail building in Malaysia, finding that carbon emissions are not concentrated at the fuelling area, but instead come from vehicle emissions, operation and maintenance. The installation of a solar photovoltaic system greatly reduces emissions and saves costs, although the return on investment may take a long time. Renewable technology can improve the built environment and air quality management in cities.
CLEANER ENGINEERING AND TECHNOLOGY
(2022)
Article
Asian Studies
Kathleen L. Purvis-Roberts
Summary: With support from EnviroLab Asia initiative, the author revamped an Environmental Chemistry course to focus on Asian environmental issues. Collaborating with UKM in Malaysia, students worked on renewable energy projects and attended a symposium. The author is now establishing a network to involve universities in the Asia-Pacific region in providing policy recommendations for the APEC Energy Working Group.
ASIANETWORK EXCHANGE-A JOURNAL FOR ASIAN STUDIES IN THE LIBERAL ARTS
(2021)
Article
Environmental Sciences
Franck Fu, Kathleen L. Purvis-Roberts, Branwen Williams
Article
Environmental Sciences
X. Tang, D. Price, E. Praske, D. N. Vu, K. Purvis-Roberts, P. J. Silva, D. R. Cocker, A. Asa-Awuku
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2014)
Article
Chemistry, Multidisciplinary
Kathleen L. Purvis-Roberts, Gretchen Edwalds-Gilbert, Adam S. Landsberg, Newton Copp, Lisa Ulsh, David E. Drew
JOURNAL OF CHEMICAL EDUCATION
(2009)
Article
Environmental Sciences
Muhammad Waqas, Majid Nazeer, Man Sing Wong, Wu Shaolin, Li Hon, Joon Heo
Summary: The socio-economic restriction measures implemented in the United States have significantly reduced nitrogen dioxide (NO2) emissions. The study highlights the impact of factors such as human mobility, population density, income, climate, and stationary sources on the reduction of NO2 at different stations. The research emphasizes the scientific impacts of the NO2 reduction and income inequality revealed by the pandemic on air quality and health disparities.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Guorui Zhi, Jinhong Du, Aizhong Chen, Wenjing Jin, Na Ying, Zhihui Huang, Peng Xu, Di Wang, Jinghua Ma, Yuzhe Zhang, Jiabao Qu, Hao Zhang, Li Yang, Zhanyun Ma, Yanjun Ren, Hongyan Dang, Jianglong Cui, Pengchuan Lin, Zhuoshi He, Jinmin Zhao, Shuo Qi, Weiqi Zhang, Wenjuan Zhao, Yingxin Li, Qian Liu, Chen Zhao, Yi Tang, Peng Wei, Jingxu Wang, Zhen Song, Yao Kong, Xiangzhe Zhu, Yi Shen, Tianning Zhang, Yangxi Chu, Xinmin Zhang, Jiafeng Fu, Qingxian Gao, Jingnan Hu, Zhigang Xue
Summary: An comprehensive emission inventory for China in 2019, which includes both air pollutants and greenhouse gases, was developed in this study. The inventory utilizes existing frameworks and data to provide comparable emissions data and demonstrates the relationship between emissions and economic development.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
I-Ting Ku, Yong Zhou, Arsineh Hecobian, Katherine Benedict, Brent Buck, Emily Lachenmayer, Bryan Terry, Morgan Frazier, Jie Zhang, Da Pan, Lena Low, Amy Sullivan, Jeffrey L. Collett Jr
Summary: Unconventional oil and natural gas development (UOGD) in the United States has expanded rapidly in recent decades, raising concerns about its impact on air quality. This study conducted extensive air monitoring during the development of several large well pads in Broomfield, Colorado, providing a unique opportunity to examine changes in local air toxics and VOC concentrations during well drilling and completions and production. The study identified significant increases in VOC concentrations during drilling operations, highlighting the importance of emissions from synthetic drilling mud. The findings suggest opportunities to mitigate emissions during UOGD operations.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Puji Lestari, Akbar R. Tasrifani, Wiranda I. Suri, Martin J. Wooster, Mark J. Grosvenor, Yusuke Fujii, Vissia Ardiyani, Elisa Carboni, Gareth Thomas
Summary: This study developed field emission factors for various pollutants in peatland fires and estimated the total emissions. Gas samples were collected using an analyzer, while particulate samples were collected using air samplers. The study found significant emissions of CO2, CO, PM2.5, carbon aerosols, water-soluble ions, and elements from the fires in Central Kalimantan, Indonesia in 2019.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Ligang Li, Yuyu Chen, Lu Fan, Dong Sun, Hu He, Yongshou Dai, Yong Wan, Fangfang Chen
Summary: A high-precision retrieval method based on a deep convolutional neural network and satellite remote sensing data is proposed to obtain accurate methane vertical profiles.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Hyung Joo Lee, Toshihiro Kuwayama, Michael Fitzgibbon
Summary: This study investigated the changes in nitrogen dioxide (NO2) air pollution levels and their disparities in California, U.S. during the pandemic of coronavirus disease 2019 (COVID-19). The results showed a decrease in NO2 concentrations, especially in urban and high-traffic areas. However, socially vulnerable populations still experienced higher levels of NO2 exposure. The study suggests that reducing NO2 disparities, particularly racial inequity, can be achieved through continued regulatory actions targeting traffic-related NOx emissions.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Maria Chiara Pietrogrande, Beatrice Biffi, Cristina Colombi, Eleonora Cuccia, Umberto Dal Santo, Luisa Romanato
Summary: This study investigates the chemical composition and oxidative potential of PM10 particles in the Po Valley, Italy, and demonstrates the impact of high levels of atmosphere ammonia. The rural area had significantly higher ammonia concentrations compared to the urban site, resulting in higher levels of secondary inorganic aerosol. Although the SIA components did not contribute significantly to the PM10 oxidative reactivity, they were correlated with the oxidative potential measurements. This suggests that the contribution of SIA to PM oxidative toxicity cannot be ignored.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Natalie Allen, Jan Gacnik, Sarrah M. Dunham-Cheatham, Mae Sexauer Gustin
Summary: Accurate measurement of atmospheric reactive mercury is challenging due to its reactivity and low concentrations. The University of Nevada, Reno Reactive Mercury Active System (RMAS) has been shown to be more accurate than the industry standard, but has limitations including long time resolution and sampling biases. Increasing the sampling flow rate negatively affected RM concentrations, but did not impact the chemical composition of RM captured on membranes.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Chin-Yu Hsu, Wei-Ting Hsu, Ching-Yi Mou, Pei-Yi Wong, Chih-Da Wu, Yu-Cheng Chen
Summary: This study estimated the daily exposure concentrations of PM2.5 for elderly individuals residing in different regions of Taiwan using land use regression with machine learning (LUR_ML) and microenvironmental exposure (ME) models. The accuracy of the models varied across regions, with the ME models exhibiting higher predictions and lower biases. The use of region-specific microenvironmental measurements in the ME model showed potential for accurate prediction of personal PM2.5 exposure.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Xiaohan Si, Kerrie Mengersen, Chuchu Ye, Wenbiao Hu
Summary: This study found that there is an interactive effect between air pollutants and weather factors, which significantly affects influenza transmission. Future research should consider the interactive effects between pollutants and temperature or humidity to evaluate the environment-influenza association.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Luxi Xu, Ruijun Xu, Yunshao Ye, Rui Wang, Jing Wei, Chunxiang Shi, Qiaoxuan Lin, Ziquan Lv, Suli Huang, Qi Tian, Yuewei Liu
Summary: This study aimed to evaluate the impact of ambient air pollution on hospital admissions for angina. The results showed that exposure to ambient particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone are associated with an increased risk of hospital admissions for angina. The association with nitrogen dioxide exposure was found to be the strongest.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Xinyu Yu, Man Sing Wong, Majid Nazeer, Zhengqiang Li, Coco Yin Tung Kwok
Summary: This study proposes a novel method to address the challenge of missing values in satellite-derived AOD products and creates a comprehensive daily AOD dataset for the Guangdong-Hong Kong-Macao Greater Bay Area. By reconstructing missing values and developing a new model, the derived dataset outperforms existing products and agrees well with ground-based observations. Additionally, the dataset exhibits consistent temporal patterns and more spatial details.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Yidan Zhang, Yifan Xu, Bo Peng, Wu Chen, Xiaoyu Cui, Tianle Zhang, Xi Chen, Yuan Yao, Mingjin Wang, Junyi Liu, Mei Zheng, Tong Zhu
Summary: This study developed a sensitive method to measure the metallic components of atmospheric fine particulate matter (PM2.5) and compared the results with different analysis methods. The concentrations of metallic components in personal PM2.5 samples were found to be significantly different from corresponding fixed-site samples. Personal sampling can reduce exposure misclassifications, and measuring metallic components is useful for exploring health risks and identifying sources of PM2.5.
ATMOSPHERIC ENVIRONMENT
(2024)
Review
Environmental Sciences
Jamie Leonard, Lea Ann El Rassi, Mona Abdul Samad, Samantha Prehn, Sanjay K. Mohanty
Summary: Increasing concentrations of microplastics in the Earth's atmosphere could have adverse effects on ecosystems and human health. The deposition rate of airborne microplastics is influenced by both land use and climate, and a global analysis suggests that climate may have a greater impact on the concentration and deposition rate of microplastics than land use.
ATMOSPHERIC ENVIRONMENT
(2024)
Article
Environmental Sciences
Tian Zhou, Xiaowen Zhou, Zining Yang, Carmen Cordoba-Jabonero, Yufei Wang, Zhongwei Huang, Pengbo Da, Qiju Luo, Zhijuan Zhang, Jinsen Shi, Jianrong Bi, Hocine Alikhodja
Summary: This study investigated the long-range transport and effects of North African and Middle Eastern dust in East Asia using lidar observations and model simulations. The results showed that the dust originated from multiple sources and had a long transport time. The vertical distribution of the dust was found to be crucial for assessing its impacts.
ATMOSPHERIC ENVIRONMENT
(2024)