Article
Ecology
Leenu Raju, R. Gandhimathi, Aneesh Mathew, S. T. Ramesh
Summary: The present study primarily focuses on describing aerosol optical depth (AOD), its distribution pattern and seasonal variation, and modelling Particulate Matter (PM) concentrations in Chennai. The study finds that AOD can be used as a proxy for estimating PM2.5 in the region, and different models have been developed for PM2.5 estimation. The Random Forest model performs the best, explaining about 53.14% of the variability in PM2.5 concentration, with a prediction error of 15.89 μg/m^3.
ECOLOGICAL INFORMATICS
(2022)
Article
Engineering, Environmental
Aaron van Donkelaar, Melanie S. Hammer, Liam Bindle, Michael Brauer, Jeffery R. Brook, Michael J. Garay, N. Christina Hsu, Olga Kalashnikova, Ralph A. Kahn, Colin Lee, Robert C. Levy, Alexei Lyapustin, Andrew M. Sayer, Randall Martin
Summary: This study developed a methodology for monthly PM2.5 estimates and uncertainties using satellite retrievals, chemical transport modeling, and ground-based measurements. Findings show higher winter PM2.5 concentrations in many densely populated regions, with South Asia and East Asia having particularly high levels, although East Asia showed a decreasing trend in PM2.5 concentrations over the period studied.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Environmental Sciences
Laaziz El Amraoui, Matthieu Plu, Vincent Guidard, Flavien Cornut, Mickael Bacles
Summary: In this study, a pre-operational forecasting assimilation system of different types of aerosols is presented. The system utilizes MODIS data to predict and anticipate extreme events and their impacts on air quality and aviation safety. The system's outputs are validated using AERONET observations, and its ability to predict extreme events such as desert dust transport and biomass burning is tested and evaluated.
Article
Geosciences, Multidisciplinary
Soon-Young Park, Uzzal Kumar Dash, Jinhyeok Yu, Keiya Yumimoto, Itsushi Uno, Chul Han Song
Summary: A data assimilation system using EnKF technique was developed to improve the simulations of a chemical transport model. Results showed consistent improvements in PM2.5 predictability through assimilating initial and boundary conditions, with relative reductions in prediction bias up to 27.2% and 17.3% for 6-hour and 24-hour predictions, respectively. Additional reductions in prediction bias (9.0%) were achieved for 24-hour PM2.5 predictions after updating boundary conditions from China.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Article
Environmental Sciences
Tianning Zhang, Weihuan He, Hui Zheng, Yaoping Cui, Hongquan Song, Shenglei Fu
Summary: The study proposed a model using satellite data to estimate PM2.5 concentrations in China in 2017, showing good performance in temporal and spatial variability. The GBDT model excelled in estimating PM2.5 concentrations, especially in summer.
Article
Multidisciplinary Sciences
Chi Li, Aaron van Donkelaar, Melanie S. Hammer, Erin E. Mcduffie, Richard T. Burnett, Joseph V. Spadaro, Deepangsu Chatterjee, Aaron J. Cohen, Joshua S. Apte, Veronica A. Southerland, Susan C. Anenberg, Michael Brauer, Randall V. Martin
Summary: Satellite observations show a recent reversal from increase to decrease in global fine particulate matter air pollution, driven by unprecedented exposure reduction in China and slowed exposure growth in South Asia, the Middle East, and Africa.
NATURE COMMUNICATIONS
(2023)
Article
Geosciences, Multidisciplinary
Yi Wang, Jun Wang, Robert C. Levy, Yingxi R. Shi, Shana Mattoo, Jeffrey S. Reid
Summary: By developing the CW-1km algorithm, spatial continuity of Aerosol Optical Depth (AOD) between land, coast, and open ocean is improved, and the availability of AOD product is increased by 47.0%. Compared with 15 years of marine aerosol network measurements, CW-1km AODs are validated to have a normalized mean bias of 1.0%, much smaller than the 17.6% for the original DT product.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Benjamin Gaubert, David P. Edwards, Jeffrey L. Anderson, Avelino F. Arellano, Jerome Barre, Rebecca R. Buchholz, Sabine Darras, Louisa K. Emmons, David Fillmore, Claire Granier, James W. Hannigan, Ivan Ortega, Kevin Raeder, Antonin Soulie, Wenfu Tang, Helen M. Worden, Daniel Ziskin
Summary: This study developed an ensemble data assimilation system to optimize initial conditions and quantify anthropogenic and wildfire emission fluxes of carbon monoxide (CO) and aerosols. The results revealed underestimation of CO emissions in China while overestimation of fire emissions, especially in the tropics. Biases in hydroxyl radical (OH) chemistry were found to dominate the CO errors.
Article
Environmental Sciences
Jianbing Jin, Mijie Pang, Arjo Segers, Wei Han, Li Fang, Baojie Li, Haochuan Feng, Hai Xiang Lin, Hong Liao
Summary: In this study, the emissions that led to the 2021 spring dust storms in East Asia were estimated through assimilation of satellite and ground-based measurements. The results revealed that both China and Mongolia contributed to the wind-blown dust emissions during these severe events. The Mongolian Gobi posed a greater threat to densely populated regions in northern China than the Chinese Gobi, with a significant proportion of the dust deposition being attributed to transnational transport.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Environmental Sciences
Syuichi Itahashi, Tatsuya Sakurai, Hikari Shimadera, Shin Araki, Hiroshi Hayami
Summary: This study analyzed the long-term trends of air pollution over the Seto Inland Sea in Japan, showing changes in AOD(f) values from 2001 to 2020, with a decrease especially after 2010. Aerosol pollution from long-range transport from the Asian continent also impacts pollution levels over the SIS. Reductions in aerosol pollution in 2020 can be attributed to the COVID-19 pandemic restrictions on human activity and regulations on SO2 emissions from ships.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Stefan Becker, Ramesh Prasad Sapkota, Binod Pokharel, Loknath Adhikari, Rudra Prasad Pokhrel, Sujan Khanal, Basant Giri
Summary: Kathmandu has high levels of particulate matter pollution and the analysis of data reveals distinct annual patterns with winter peaks and summer lows. Despite variations throughout the day and year, public health guidelines are frequently exceeded, particularly during winter. Remote sensing data provides a valuable alternative approach to studying pollution levels and understanding their variability in the Kathmandu valley.
ATMOSPHERIC RESEARCH
(2021)
Article
Environmental Sciences
Mounir Chrit, Marwa Majdi
Summary: This study assimilated MODIS AOD data into the Chimere model in Europe to improve modeling of PM2.5 concentrations and AOD field. Evaluation showed that data assimilation technique can push the model results closer to surface observations, but the difficulty in distributing AOD over different particle sizes may lead to false alarms.
Article
Chemistry, Analytical
Sung Hoon Baek
Summary: Fine particulate matter is harmful to health, and conventional PM monitors can have errors under high humidity. This study presents a new type of PM monitor that improves energy efficiency and dehumidification by changing the structure of the dryer and the direction of air flow. Experimental results show that the proposed monitor meets the relevant indicators.
Article
Environmental Sciences
Nicolae Ajtai, Alexandru Mereuta, Horatiu Stefanie, Andrei Radovici, Camelia Botezan, Olga Zawadzka-Manko, Iwona S. Stachlewska, Kerstin Stebel, Claus Zehner
Summary: This study validates the AOD retrieved from SEVIRI data by comparing it with AERONET, Poland-AOD, and MODIS data. The results show that the SEVIRI AOD has the best correlation with AERONET, followed by Poland-AOD and MODIS. A revised uncertainty estimate is proposed based on the observed bias from the AERONET validation efforts.
Article
Environmental Sciences
Jiongming Pang, Xuemei Wang
Summary: Accurate estimation of background error covariance (BEC) is essential for successful data assimilation (DA), especially in aerosol three-dimensional variational (3DVAR) DA. A modified module was developed to adjust the BEC of individual aerosol species, showing that horizontal length scales play a more crucial role than standard deviations in the impacts of BEC on PM(10 )24-hour forecast. The study highlights the importance of modifying aerosol BEC in 3DVAR for better aerosol forecast and analysis, especially during polluted periods.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Multidisciplinary Sciences
Brian C. McDonald, Joost A. de Gouw, Jessica B. Gilman, Shantanu H. Jathar, Ali Akherati, Christopher D. Cappa, Jose L. Jimenez, Julia Lee-Taylor, Patrick L. Hayes, Stuart A. McKeen, Yu Yan Cui, Si-Wan Kim, Drew R. Gentner, Gabriel Isaacman-VanWertz, Allen H. Goldstein, Robert A. Harley, Gregory J. Frost, James M. Roberts, Thomas B. Ryerson, Michael Trainer
Article
Environmental Sciences
Renate Forkel, Johannes Werhahn, Ayoe Buus Hansen, Stuart McKeen, Steven Peckham, Georg Grell, Peter Suppan
ATMOSPHERIC ENVIRONMENT
(2012)
Article
Engineering, Environmental
R. Bahreini, A. M. Middlebrook, C. A. Brock, J. A. de Gouw, S. A. McKeen, L. R. Williams, K. E. Daumit, A. T. Lambe, P. Massoli, M. R. Canagaratna, R. Ahmadov, A. J. Carrasquillo, E. S. Cross, B. Ervens, J. S. Holloway, J. F. Hunter, T. B. Onasch, I. B. Pollack, J. M. Roberts, T. B. Ryerson, C. Warneke, P. Davidovits, D. R. Worsnop, J. H. Kroll
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2012)
Article
Geosciences, Multidisciplinary
J. B. Nowak, J. A. Neuman, R. Bahreini, A. M. Middlebrook, J. S. Holloway, S. A. McKeen, D. D. Parrish, T. B. Ryerson, M. Trainer
GEOPHYSICAL RESEARCH LETTERS
(2012)
Article
Meteorology & Atmospheric Sciences
J. Brioude, G. Petron, G. J. Frost, R. Ahmadov, W. M. Angevine, E. -Y. Hsie, S. -W. Kim, S. -H. Lee, S. A. McKeen, M. Trainer, F. C. Fehsenfeld, J. S. Holloway, J. Peischl, T. B. Ryerson, K. R. Gurney
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2012)
Article
Meteorology & Atmospheric Sciences
R. Ahmadov, S. A. McKeen, A. L. Robinson, R. Bahreini, A. M. Middlebrook, J. A. de Gouw, J. Meagher, E-Y Hsie, E. Edgerton, S. Shaw, M. Trainer
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2012)
Article
Multidisciplinary Sciences
Ann M. Middlebrook, Daniel M. Murphy, Ravan Ahmadov, Elliot L. Atlas, Roya Bahreini, Donald R. Blake, Jerome Brioude, Joost A. de Gouw, Fred C. Fehsenfeld, Gregory J. Frost, John S. Holloway, Daniel A. Lack, Justin M. Langridge, Rich A. Lueb, Stuart A. McKeen, James F. Meagher, Simone Meinardi, J. Andrew Neuman, John B. Nowak, David D. Parrish, Jeff Peischl, Anne E. Perring, Ilana B. Pollack, James M. Roberts, Thomas B. Ryerson, Joshua P. Schwarz, J. Ryan Spackman, Carsten Warneke, A. R. Ravishankara
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2012)
Article
Meteorology & Atmospheric Sciences
Agnes Borbon, J. B. Gilman, W. C. Kuster, N. Grand, S. Chevaillier, A. Colomb, C. Dolgorouky, V. Gros, M. Lopez, R. Sarda-Esteve, J. Holloway, J. Stutz, H. Petetin, S. McKeen, M. Beekmann, C. Warneke, D. D. Parrish, J. A. de Gouw
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2013)
Article
Geosciences, Multidisciplinary
Li Zhang, Raffaele Montuoro, Stuart A. McKeen, Barry Baker, Partha S. Bhattacharjee, Georg A. Grell, Judy Henderson, Li Pan, Gregory J. Frost, Jeff McQueen, Rick Saylor, Haiqin Li, Ravan Ahmadov, Jun Wang, Ivanka Stajner, Shobha Kondragunta, Xiaoyang Zhang, Fangjun Li
Summary: This paper describes the development of the GEFS-Aerosols model and evaluates its real-time and retrospective runs using various observations. The GEFS-Aerosols system shows significant improvements in the composition and variability of aerosol distributions compared to the previous NGACv2 system.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Article
Geosciences, Multidisciplinary
Li Zhang, Georg A. Grell, Stuart A. McKeen, Ravan Ahmadov, Karl D. Froyd, Daniel Murphy
Summary: The global Flow-following finite-volume Icosahedral Model (FIM) has been coupled with aerosol and gas-phase chemistry schemes to simulate aerosol and gas-phase chemical species at different complexities. The model performance has been evaluated by comparing the results with observational data.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Article
Environmental Sciences
J. Brioude, W. M. Angevine, R. Ahmadov, S. -W. Kim, S. Evan, S. A. McKeen, E. -Y. Hsie, G. J. Frost, J. A. Neuman, I. B. Pollack, J. Peischl, T. B. Ryerson, J. Holloway, S. S. Brown, J. B. Nowak, J. M. Roberts, S. C. Wofsy, G. W. Santoni, T. Oda, M. Trainer
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2013)
Article
Geosciences, Multidisciplinary
J. Brioude, W. M. Angevine, S. A. McKeen, E. -Y. Hsie
GEOSCIENTIFIC MODEL DEVELOPMENT
(2012)
Article
Geosciences, Multidisciplinary
M. Stuefer, S. R. Freitas, G. Grell, P. Webley, S. Peckham, S. A. McKeen, S. D. Egan
GEOSCIENTIFIC MODEL DEVELOPMENT
(2013)
Article
Environmental Sciences
D. D. Parrish, T. B. Ryerson, J. Mellqvist, J. Johansson, A. Fried, D. Richter, J. G. Walega, R. A. Washenfelder, J. A. de Gouw, J. Peischl, K. C. Aikin, S. A. McKeen, G. J. Frost, F. C. Fehsenfeld, S. C. Herndon
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2012)