Article
Environmental Sciences
Chao Wang, Xingqin An, Defeng Zhao, Zhaobin Sun, Linsen Jiang, Jiangtao Li, Qing Hou
Summary: This study presents the development and validation of the gaseous chemistry adjoint module for the GRAPES-CUACE meteorological-chemical model system. The adjoint model accurately captures the relationship between ozone concentration and precursor emissions, providing valuable guidance for environmental control policies.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Green & Sustainable Science & Technology
Mengya Wang, Tao Huang, David C. Wong, Kin Fai Ho, Guanghui Dong, Steve H. L. Yim
Summary: This study introduces an adjoint-based optimization framework to facilitate health-oriented O3 control in the Pearl River Delta Region (PRD). Results show that the regional O3 health benefits can be increased by 16-27% under current emission reduction policy, with significant reductions in NOx emissions observed in highly developed and populated areas such as Shenzhen and urban Guangzhou.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Geosciences, Multidisciplinary
F. Robertson, L. E. Revell, H. Douglas, A. T. Archibald, O. Morgenstern, D. Frame
Summary: The year when total column ozone (TCO) returns to 1980 levels is commonly used to measure recovery from ozone-depleting substances. However, this metric fails to account for internal variability and the timing of significant TCO losses. Using the signal-to-noise (S/N) metric, this study investigates how TCO can return to pre-disturbance conditions. The findings suggest that TCO de-emerges before returning to its 1980 value, making S/N a suitable metric for determining TCO recovery.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
F. Robertson, L. E. Revell, H. Douglas, A. T. Archibald, O. Morgenstern, D. Frame
Summary: Research suggests that the year when total column ozone (TCO) returns to 1980 levels is commonly used as an indicator of recovery from ozone-depleting substances. However, this date is somewhat arbitrary. In this study, the signal-to-noise (S/N) metric from climate change research is used to investigate how TCO might return to pre-ozone hole era levels. The findings show that a return to 1980 levels does not necessarily represent TCO recovery to pre-disturbance conditions, and the S/N ratio is a more appropriate and complementary metric.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
Dennis L. Hartmann
Summary: Since 1980, the tropical Pacific has been anomalously cold, potentially associated with the Antarctic ozone hole.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Environmental Sciences
Yixuan Gu, Daven K. Henze, M. Omar Nawaz, Ulrich J. Wagner
Summary: This study quantifies the impact of changes in anthropogenic emissions of O-3 precursors on premature deaths from long-term O-3 exposure in Europe. The research finds that reducing NOx emissions can decrease premature deaths in most of Europe, but may cause more deaths in areas where O-3 formation is NOx-saturated. The study also highlights that O-3 formation becomes less sensitive to volatile organic compound emissions and more limited by NOx emissions over time. Consequently, costlier regulations of NOx emissions are economically justified, and regulations targeted at road transport, industry, energy, and residential sectors will yield the highest health benefits per unit NOx emission.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Thibaud M. Fritz, Irene C. Dedoussi, Sebastian D. Eastham, Raymond L. Speth, Daven K. Henze, Steven R. H. Barrett
Summary: Depletion of stratospheric ozone and increase in global net ozone from emissions of different types of aircraft were studied. The study used a simulation tool to identify the location of the column ozone-neutral cruise altitude, which was found to vary with factors such as latitude and season.
ATMOSPHERIC ENVIRONMENT
(2022)
Article
Meteorology & Atmospheric Sciences
Yingli Niu, Fei Xie, Shaohua Wu
Summary: This study investigated the impact of ENSO Modoki on Antarctic stratospheric ozone variability in austral spring using observation and reanalysis data. It found that ENSO Modoki generates planetary wave anomalies in the troposphere, which subsequently affect the polar vortex and interannual variations in Antarctic stratospheric ozone. Analysis also revealed that wave-1 and wave-3 components play a significant role, while wave-2 effects are opposite and offset by waves 1 and 3. Furthermore, the study evaluated the performance of CMIP6 models in simulating the impacts of ENSO Modoki on the southern stratospheric polar vortex and ozone, finding that only two models closely resemble the reanalysis results.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
I Wohltmann, P. von der Gathen, R. Lehmann, H. Deckelmann, G. L. Manney, J. Davies, D. Tarasick, N. Jepsen, R. Kivi, N. Lyall, M. Rex
Summary: The winter of 2019/2020 in the Arctic stratosphere had the lowest observed ozone mixing ratios and was characterized by an unusually strong and long-lasting polar vortex. Some aspects of this winter resemble both Antarctic and Arctic conditions, such as the chemical processes and chlorine activation reactions. If the air masses had spent slightly more time below the upper temperature limit for polar stratospheric cloud formation and in sunlight, ozone levels in parts of the vortex could have been reduced to near zero values.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Meteorology & Atmospheric Sciences
N. A. Davis, D. Visioni, R. R. Garcia, D. E. Kinnison, D. R. Marsh, M. Mills, J. H. Richter, S. Tilmes, C. G. Bardeen, A. Gettelman, A. A. Glanville, D. G. Macmartin, A. K. Smith, F. Vitt
Summary: Simulating the dynamics, chemistry, and physics of the entire atmosphere is computationally expensive. Simplified chemistry configurations can reliably simulate the whole atmosphere with reduced computational resources, except for cases requiring an accurate representation of tropospheric organic chemistry and secondary organic aerosols.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Meteorology & Atmospheric Sciences
Jun Zhang, Donald Wuebbles, Douglas Kinnison, Steven L. Baughcum
Summary: This study evaluates the potential impact on stratospheric ozone and climate forcing from supersonic aircraft emissions. The results show that the effects largely depend on levels of nitrogen oxides and water vapor emissions, with chemical interactions playing a key role in ozone production and depletion cycles. Assessing the radiative forcing impact from changes in ozone and water vapor distributions, the study confirms the importance of stratospheric water vapor emissions in potential climate impacts.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Meteorology & Atmospheric Sciences
Xiang Xiao, Yangyang Xu, Xiaorui Zhang, Fan Wang, Xiao Lu, Zongwei Cai, Guy Brasseur, Meng Gao
Summary: This study investigates the cooccurrences of heat and air pollution extremes in China. The results show a significant increase in the frequency of joint exceedances of wet-bulb temperature (w) and O-3, mainly in the Beijing-Tianjin-Hebei region and the Yangtze River delta. Moreover, the rate of joint exceedance is higher than the rate of T-w and O-3 themselves.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2022)
Article
Engineering, Environmental
Yuhan Wang, Lucas Bastien, Ling Jin, Robert A. Harley
Summary: Ground-level ozone has negative impacts on human health and ecosystems. In California's San Joaquin Valley (SJV), the effectiveness of controlling precursor emissions on ozone levels depends on the time and location of the emissions. The study shows that the impacts of local emissions and emissions from surrounding areas are similar in magnitude in the SJV. Same-day emission impacts are mainly attributed to local sources, with the most influential emissions of volatile organic compounds (VOCs) and nitrogen oxides (NOx) occurring in the morning and early afternoon. The influence from emissions in the Sacramento Valley peaks 5-6 hours later than emissions from the San Francisco Bay area for the northernmost SJV receptor, but this difference diminishes for receptors located further downwind. There is a shift towards NOx-sensitive conditions in the afternoon for all receptors except the southernmost one.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Statistics & Probability
Mirrelijn M. van Nee, Tim van de Brug, Mark A. van de Wiel
Summary: Elastic net penalization is a widely used method in high-dimensional prediction and variable selection. Group-adaptive elastic net penalization exploits auxiliary information on variables to improve performance. However, existing methods are computationally expensive or have limitations. This study presents a fast method for estimation of group-adaptive elastic net penalties in generalized linear models, allowing for improved computation time and performance.
JOURNAL OF COMPUTATIONAL AND GRAPHICAL STATISTICS
(2023)
Article
Meteorology & Atmospheric Sciences
Leonhard Hufnagl, Roland Eichinger, Hella Garny, Thomas Birner, Ales Kuchar, Patrick Joeckel, Phoebe Graf
Summary: The increase in atmospheric CO2 concentrations affects circulation by changing the atmospheric temperature distribution. This study quantifies the modification of the circulation response to CO2 forcing by stratospheric ozone through model simulations. The results show that ozone changes dampen the CO2-induced strengthening of the circulation, leading to various impacts on temperature gradients and polar vortices.
JOURNAL OF CLIMATE
(2023)
Article
Environmental Sciences
Jun-Wei Xu, Randall V. Martin, Barron H. Henderson, Jun Meng, Y. Burak Oztaner, Jenny L. Hand, Amir Hakami, Madeleine Strum, Sharon B. Phillips
ATMOSPHERIC ENVIRONMENT
(2019)
Article
Environmental Sciences
Tanya Christidis, Anders C. Erickson, Amanda J. Pappin, Daniel L. Crouse, Lauren L. Pinault, Scott A. Weichenthal, Jeffrey R. Brook, Aaron van Donkelaar, Perry Hystad, Randall V. Martin, Michael Tjepkema, Richard T. Burnett, Michael Brauer
ENVIRONMENTAL HEALTH
(2019)
Article
Environmental Sciences
Amanda J. Pappin, Tanya Christidis, Lauren L. Pinault, Dan L. Crouse, Jeffrey R. Brook, Anders Erickson, Perry Hystad, Chi Li, Randall V. Martin, Jun Meng, Scott Weichenthal, Aaron van Donkelaar, Michael Tjepkema, Michael Brauer, Richard T. Burnett
ENVIRONMENTAL HEALTH PERSPECTIVES
(2019)
Article
Public, Environmental & Occupational Health
Dan L. Crouse, Anders C. Erickson, Tanya Christidis, Lauren Pinault, Aaron van Donkelaar, Chi Li, Jun Meng, Randall Martin, Michael Tjepkema, Perry Hystad, Rick Burnett, Amanda Pappin, Michael Brauer, Scott Weichenthal
Article
Environmental Sciences
Congmeng Lyu, Shannon L. Capps, Amir Hakami, Shunliu Zhao, Jaroslav Resler, Gregory R. Carmichael, Adrian Sandu, Armistead G. Russell, Tianfeng Chai, Daven K. Henze
ENVIRONMENTAL RESEARCH LETTERS
(2019)
Article
Psychology, Biological
Huizhong Shen, Guofeng Shen, Yilin Chen, Armistead G. Russell, Yongtao Hu, Xiaoli Duan, Wenjun Meng, Yang Xu, Xiao Yun, Baolei Lyu, Shunliu Zhao, Amir Hakami, Jianping Guo, Shu Tao, Kirk R. Smith
Summary: Despite a decrease in outdoor PM2.5 during the COVID-19 quarantine in China, overall population exposure to PM2.5 increased. This was mainly driven by population migration from urban to rural areas before the Spring Festival, coupled with increased household energy consumption during the quarantine, leading to a higher percentage of people exposed to rural household air pollution.
NATURE HUMAN BEHAVIOUR
(2021)
Article
Environmental Sciences
Congmeng Lyu, Shannon L. Capps, Kent Kurashima, Daven K. Henze, Gordon Pierce, Amir Hakami, Shunliu Zhao, Jaroslav Resler, Gregory R. Carmichael, Adrian Sandu, Armistead G. Russell, Tianfeng Chai, Jana Milford
Summary: Recent expansion of oil and natural gas production activities in the Denver-Julesburg Basin have led to significant increase in nonmethane hydrocarbon (NMHC) emissions, contributing to ground-level ozone formation. Using different methods, it was estimated that O&NG activities in Platteville and Denver have different contributions to NMHC mixing ratios. Vehicle emissions in Denver have a larger impact on NMHC levels compared to O&NG activities.
ATMOSPHERIC ENVIRONMENT
(2021)
Article
Environmental Sciences
Sina Voshtani, Richard Menard, Thomas W. Walker, Amir Hakami
Summary: This study presents a parametric Kalman filter data assimilation system using GOSAT methane observations within the hemispheric CMAQ model. The system can generate forecasts and analyses of concentrations and computes its evolving error variance while remaining computationally competitive. The study also discusses extensions to include methane transport and emissions in the CMAQ model and perform a bias correction for the GOSAT observations.
Article
Environmental Sciences
Sina Voshtani, Richard Menard, Thomas W. Walker, Amir Hakami
Summary: We applied the parametric variance Kalman filter (PvKF) data assimilation to GOSAT methane observations and optimized the methane field with its error variance. The assimilation results were validated and showed significant improvement compared to available observations. Additionally, the method was able to capture the spatial structure of bias and uncertainty reduction across the Northern Hemisphere.
Article
Environmental Sciences
Sina Voshtani, Richard Menard, Thomas W. Walker, Amir Hakami
Summary: This study combines parametric variance Kalman filter (PvKF) assimilation with 4D-Var inversion to improve methane emissions estimation. It revisits the assumptions made in the traditional 4D-Var algorithm and objectively accounts for error correlations and the evolution of analysis error variances. Experimental results show that using PvKF optimal analysis instead of the model forecast improves posterior emissions estimate and retains the effects of background correlation structures, resulting in more reliable estimates of posterior emissions. The addition of PvKF optimal analysis field benefits the 4D-Var inversion by reducing computational time.
Article
Environmental Sciences
Yilin Chen, Huizhong Shen, Jennifer Kaiser, Yongtao Hu, Shannon L. Capps, Shunliu Zhao, Amir Hakami, Jhih-Shyang Shih, Gertrude K. Pavur, Matthew D. Turner, Daven K. Henze, Jaroslav Resler, Athanasios Nenes, Sergey L. Napelenok, Jesse O. Bash, Kathleen M. Fahey, Gregory R. Carmichael, Tianfeng Chai, Lieven Clarisse, Pierre-Francois Coheur, Martin Van Damme, Armistead G. Russell
Summary: Ammonia emissions have significant impacts on air quality and nitrogen deposition, with large uncertainties existing in bottom-up emission inventories. This study utilizes satellite measurements and modeling tools to optimize NH3 emission estimates, revealing a 26% underestimation in the 2011 NEI with overestimation in the Midwest and underestimation in the Southern States.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Geosciences, Multidisciplinary
Shunliu Zhao, Matthew G. Russell, Amir Hakami, Shannon L. Capps, Matthew D. Turner, Daven K. Henze, Peter B. Percell, Jaroslav Resler, Huizhong Shen, Armistead G. Russell, Athanasios Nenes, Amanda J. Pappin, Sergey L. Napelenok, Jesse O. Bash, Kathleen M. Fahey, Gregory R. Carmichael, Charles O. Stanier, Tianfeng Chai
GEOSCIENTIFIC MODEL DEVELOPMENT
(2020)
Article
Environmental Sciences
Matthew Russell, Amir Hakami, Paul A. Makar, Ayodeji Akingunola, Junhua Zhang, Michael D. Moran, Qiong Zheng
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2019)