Article
Environmental Sciences
Chaeyoon Cho, Sang-Woo Kim, Woosuk Choi, Man-Hae Kim
Summary: This study investigated the contribution of brown carbon (BrC) to the absorption aerosol optical depth (AAOD) in California during the August to October 2020 wildfires, finding a significant daily variation in BrC contribution correlated with fire pixel counts. The average BrC contribution to AAOD due to wildfires in Fresno, Monterey, and UCSB was approximately twice as high as sites without direct wildfire influence. Additionally, the BrC contribution from wildfires was approximately 20% greater than other BrC sources from various activities.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Meteorology & Atmospheric Sciences
Linghan Zeng, Amy P. Sullivan, Rebecca A. Washenfelder, Jack Dibb, Eric Scheuer, Teresa L. Campos, Joseph M. Katich, Ezra Levin, Michael A. Robinson, Rodney J. Weber
Summary: This study conducted direct online measurements of water-soluble BrC using three separate instruments on research aircraft, providing valuable insights into its concentration, sources, evolution, and impacts.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2021)
Article
Engineering, Environmental
Lu Zhang, Zhihan Luo, Yaojie Li, Yuanchen Chen, Wei Du, Gang Li, Hefa Cheng, Guofeng Shen, Shu Tao
Summary: This study assessed particulate BC and BrC emissions from real-world indoor coal and biomass burning, finding that coal cake combustion had the highest BC EF and charcoal burning had the highest BrC EF. Using iron stoves for burning fuel resulted in lower BC and BrC EFs, and the difference between heating and cooking activities was not statistically significant.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Geosciences, Multidisciplinary
R. A. Washenfelder, L. Azzarello, K. Ball, S. S. Brown, Z. C. J. Decker, A. Franchin, C. D. Fredrickson, K. Hayden, C. D. Holmes, A. M. Middlebrook, B. B. Palm, R. B. Pierce, D. J. Price, J. M. Roberts, M. A. Robinson, J. A. Thornton, C. C. Womack, C. J. Young
Summary: We investigated the light absorption characteristics of brown carbon after wildfires through sampling and measurement. The results showed that the mass absorption coefficient of brown carbon varied with plume age on a certain time scale, and there were no identifiable contributions from individual chromophores with structured absorption.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Fuying Tang, Weihe Wang, Fuqi Si, Haijin Zhou, Yuhan Luo, Yuanyuan Qian
Summary: This study presented the retrieval of absorbing aerosol index (AAI) for the first time using the Environmental Trace Gases Monitoring Instrument (EMI) on the Chinese GeoFen-5 satellite. The results showed that EMI AAI was consistent with TROPOMI AAI, both in terms of regional distribution and daily variations. The study demonstrated that EMI AAI can be effectively used to detect large aerosol events and reconstruct the spatial variability of UV absorbing aerosols.
Article
Meteorology & Atmospheric Sciences
Sang-Woo Kim, Chaeyoon Cho, Maheswar Rupakheti
Summary: In the highly polluted Kathmandu Valley, Nepal, the individual contributions of black carbon (BC) and brown carbon (BrC) to aerosol absorption were estimated. The study found that BC and BrC contributions varied significantly, with a substantial increase in aerosol absorption observed during winter and premonsoon periods due to biomass burning activities. The research also showed a strong correlation between surface aethalometer-based and column AERONET-based estimates for BC and BrC absorption.
ATMOSPHERIC RESEARCH
(2021)
Article
Environmental Sciences
Igor B. Konovalov, Nikolai A. Golovushkin, Matthias Beekmann, Solene Turquety
Summary: This study examined the feasibility of statistically characterizing the evolution of BrC absorption and related parameters in smoke plumes from intense wildfires in Siberia using a combination of data from three satellite instruments. The results showed a significant decrease in BrC absorption over time, but it remained considerable. This study provides valuable insights into the atmospheric evolution of BrC absorption and the partitioning of BrC and BC contributions to the total light absorption by BB aerosol.
Article
Environmental Sciences
Chunmao Zhu, Takuma Miyakawa, Hitoshi Irie, Yongjoo Choi, Fumikazu Taketani, Yugo Kanaya
Summary: Brown carbon (BrC) aerosols have important warming effects on Earth's radiative forcing. This study evaluated the evolution of the light-absorption properties of BrC aerosols in the Asian outflow region using in-situ filter measurements and sky radiometer observations. The results showed a positive correlation between the light-absorption properties of BrC obtained from different methods, suggesting successful capture of BrC dynamics and climatic effects in East Asia.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Yuan Gao, Qiyuan Wang, Li Li, Wenting Dai, Jinjiang Yu, Limin Ding, Jianjun Li, Bo Xin, Weikang Ran, Yongming Han, Junji Cao
Summary: This study investigated the light-absorbing properties of primary and secondary Brown carbon (BrC) using the black carbon (BC) tracer method at Mount Hua, China during the 2018 summer period. The results showed that traffic emissions were the main source of primary BrC absorption, while secondary BrC was mainly influenced by secondary formation, indicating the importance of secondary BrC in light absorption in mountainous areas.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Linghan Zeng, Jack Dibb, Eric Scheuer, Joseph M. Katich, Joshua P. Schwarz, Ilann Bourgeois, Jeff Peischl, Tom Ryerson, Carsten Warneke, Anne E. Perring, Glenn S. Diskin, Joshua P. DiGangi, John B. Nowak, Richard H. Moore, Elizabeth B. Wiggins, Demetrios Pagonis, Hongyu Guo, Pedro Campuzano-Jost, Jose L. Jimenez, Lu Xu, Rodney J. Weber
Summary: This study investigates the characteristics and evolution of brown carbon (BrC) associated with aerosol particles during wildfires in the western United States. Two measurement methods were employed, one using solvent extracts and the other using in situ aerosol particle light absorption measurements. The results show a relationship between BrC absorption and carbon monoxide (CO) emissions. The study also reveals the complex evolution of BrC in the first 8 hours after emission, including enhancements, depletions, or constant levels. Ozone and temperature were found to be influential factors in the formation and evolution of BrC.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Engineering, Environmental
Haiyan Ni, Ru-Jin Huang, Simone M. Pieber, Joel C. Corbin, Giulia Stefenelli, Veronika Pospisilova, Felix Klein, Martin Gysel-Beer, Lu Yang, Urs Baltensperger, Imad El Haddad, Jay G. Slowik, Junji Cao, Andre S. H. Prevot, Ulrike Dusek
Summary: The experiments found that even after aging, most BrC is still insoluble in water. The mass absorption efficiency of primary organic aerosol (POA) was significantly higher than that of aged organic aerosol (SOA). Residential coal combustion emissions were among the strongest absorbing BrC organics among anthropogenic sources.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Lulu Xu, Yiran Peng, Kirpa Ram, Yanlin Zhang, Mengying Bao, Jing Wei
Summary: Recent studies have shown that including brown carbon (BrC) in global climate models can correct the underestimated aerosol absorption, but also introduce uncertainties. The impact of BrC on aerosol absorption simulations varies in different cities.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Geosciences, Multidisciplinary
Rajan K. Chakrabarty, Nishit J. Shetty, Arashdeep S. Thind, Payton Beeler, Benjamin J. Sumlin, Chenchong Zhang, Pai Liu, Juan C. Idrobo, Kouji Adachi, Nicholas L. Wagner, Joshua P. Schwarz, Adam Ahern, Arthur J. Sedlacek, Andrew Lambe, Conner Daube, Ming Lyu, Chao Liu, Scott Herndon, Timothy B. Onasch, Rohan Mishra
Summary: Observations of smoke plumes in the United States shows that atmospheric short-wave absorption due to wildfire smoke is mainly caused by dark brown carbon particles. Wildfires release large amounts of black carbon and light-absorbing organic carbon, known as brown carbon, into the atmosphere, which disrupts Earth's radiation budget. It is important to quantify these radiative impacts as wildfires are predicted to increase globally.
Article
Meteorology & Atmospheric Sciences
Adam T. Ahern, Frank Erdesz, Nicholas L. Wagner, Charles A. Brock, Ming Lyu, Kyra Slovacek, Richard H. Moore, Elizabeth B. Wiggins, Daniel M. Murphy
Summary: This paper presents an improved imaging nephelometer, LiNeph, for measuring the directionality and polarization of light with high temporal resolution. It can be deployed in both airborne and ground-based measurements, and has been verified during the 2019 FIREX-AQ campaign.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2022)
Article
Chemistry, Medicinal
Ditte B. Hermund, Hanna Torsteinsen, Julia Vega, Felix L. Figueroa, Charlotte Jacobsen
Summary: Phlorotannins in brown algae can function as photo-protectors and antioxidants in skin care formulations, but the current concentration of UV protecting compounds in the extracts is too low and needs further improvement.
Article
Multidisciplinary Sciences
Shang Liu, Cheng-Cheng Liu, Karl D. Froyd, Gregory P. Schill, Daniel M. Murphy, T. Paul Bui, Jonathan M. Dean-Day, Bernadett Weinzierl, Maximilian Dollner, Glenn S. Diskin, Gao Chen, Ru-Shan Gao
Summary: Research shows that higher sea surface temperature (SST) promotes the generation of sea spray aerosol (SSA) mass in the remote Pacific and Atlantic Oceans, and considering SST greatly enhances the predictability of SSA concentration variability.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Meteorology & Atmospheric Sciences
Therese S. Carter, Colette L. Heald, Christopher D. Cappa, Jesse H. Kroll, Teresa L. Campos, Hugh Coe, Michael Cotterell, Nicholas W. Davies, Delphine K. Farmer, Cathyrn Fox, Lauren A. Garofalo, Lu Hu, Justin M. Langridge, Ezra J. T. Levin, Shane M. Murphy, Rudra P. Pokhrel, Yingjie Shen, Kate Szpek, Jonathan W. Taylor, Huihui Wu
Summary: Biomass burning produces carbonaceous aerosols that significantly impact air quality and climate. Modeling shows underestimated BC emissions in southern Africa, with higher BC and/or BrC absorption downwind of Africa compared to the western United States.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Engineering, Chemical
Rachael Dal Porto, Monet N. Kunz, Theresa Pistochini, Richard L. Corsi, Christopher D. Cappa
Summary: Air filtration can reduce particle concentrations in indoor environments. The Corsi-Rosenthal air cleaner has been shown to efficiently reduce suspended particle concentrations in indoor environments.
AEROSOL SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Environmental
Yicong He, Andrew T. Lambe, John H. Seinfeld, Christopher D. Cappa, Jeffrey R. Pierce, Shantanu H. Jathar
Summary: In this study, a kinetic model for secondary organic aerosol (SOA) was developed and used to explain the evolution of SOA in both environmental chambers (ECs) and oxidation flow reactors (OFRs). The results show that by considering various processes, the model is able to explain the observed changes in SOA mass, composition, and size distribution.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Karl D. Froyd, Pengfei Yu, Gregory P. Schill, Charles A. Brock, Agnieszka Kupc, Christina J. Williamson, Eric J. Jensen, Eric Ray, Karen H. Rosenlof, Huisheng Bian, Anton S. Darmenov, Peter R. Colarco, Glenn S. Diskin, ThaoPaul Bui, Daniel M. Murphy
Summary: Mineral dust particles play a critical role in the formation of cirrus clouds, according to global-scale dust observations and a cirrus-formation model. The formation of cirrus clouds in the Northern Hemisphere is primarily triggered by mineral dust.
Article
Chemistry, Physical
Christopher M. Jernigan, Christopher D. Cappa, Timothy H. Bertram
Summary: The oxidation products of DMS contribute to the production and growth of cloud condensation nuclei. However, there is a lack of experimental measurements of the reactive uptake of HPMTF to aerosol particles. This study measured the reactive uptake coefficient of HPMTF to different types of aerosol particles using an aerosol flow reactor combined with chemical ionization mass spectrometry.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Engineering, Environmental
Emily B. Franklin, Sarah Amiri, Daniel Crocker, Clare Morris, Kathryn Mayer, Jonathan S. Sauer, Robert J. Weber, Christopher Lee, Francesca Malfatti, Christopher D. Cappa, Timothy H. Bertram, Kimberly A. Prather, Allen H. Goldstein
Summary: The organic composition of coastal sea spray aerosol, which is influenced by both human activities and biological processes, is investigated in this study. Through analyzing samples collected during a phytoplankton bloom experiment, it is found that the representation of biogenic marine organics is lower in mass spectral databases compared to marine organic pollutants.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Susan Solomon, Kane Stone, Pengfei Yu, D. M. Murphy, Doug Kinnison, A. R. Ravishankara, Peidong Wang
Summary: Remarkable changes in stratospheric chlorine species and ozone were observed after the 2020 Australian wildfires. Wildfire aerosols containing oxidized organics and sulfate increase hydrochloric acid solubility and reaction rates, activating reactive chlorine species and enhancing ozone loss rates. Comparisons between atmospheric observations and model simulations show agreement, indicating that wildfire aerosol chemistry can lead to an increase in the area of the ozone hole and a depletion of mid-latitude total column ozone. These findings raise concerns about the potential delay in ozone recovery due to more frequent and intense wildfires in a warming world.
Review
Geochemistry & Geophysics
Ralph A. A. Kahn, Elisabeth Andrews, Charles A. A. Brock, Mian Chin, Graham Feingold, Andrew Gettelman, Robert C. C. Levy, Daniel M. M. Murphy, Athanasios Nenes, Jeffrey R. R. Pierce, Thomas Popp, Jens Redemann, Andrew M. M. Sayer, Arlindo M. M. da Silva, Larisa Sogacheva, Philip Stier
Summary: Aerosol forcing uncertainty remains the largest climate forcing uncertainty and has not diminished significantly in the past 20 years. This review summarizes the contributions made by satellite observations, atmospheric measurements, modeling, and data assimilation to reduce the uncertainty in aerosol forcing of climate. The review highlights the need for systematic aircraft in situ measurements, suborbital programs, and integration of satellite observations, measurements, and modeling to reduce the persistent uncertainty in aerosol climate forcing.
REVIEWS OF GEOPHYSICS
(2023)
Article
Multidisciplinary Sciences
J. M. Katich, E. C. Apel, I. Bourgeois, C. A. Brock, T. P. Bui, P. Campuzano-Jost, R. Commane, B. Daube, M. Dollner, M. Fromm, K. D. Froyd, A. J. Hills, R. S. Hornbrook, J. L. Jimenez, A. Kupc, K. D. Lamb, K. McKain, F. Moore, D. M. Murphy, B. A. Nault, J. Peischl, A. E. Perring, D. A. Peterson, E. A. Ray, K. H. Rosenlof, T. Ryerson, G. P. Schill, J. C. Schroder, B. Weinzierl, C. Thompson, C. J. Williamson, S. C. Wofsy, P. Yu, J. P. Schwarz
Summary: Pyrocumulonimbus (pyroCb) are wildfire-generated convective clouds that can inject smoke directly into the stratosphere. In situ measurements of pyroCb smoke reveal its distinctive and exceptionally stable aerosol properties and define the long-term influence of pyroCb activity on the stratospheric aerosol budget. Analysis of 13 years of airborne observations shows that pyroCb are responsible for 10 to 25% of the black carbon and organic aerosols in the present-day lower stratosphere, with similar impacts in both the North and South Hemispheres. These results suggest that, should pyroCb increase in frequency and/or magnitude in future climates, they could generate dominant trends in stratospheric aerosol.
Article
Environmental Sciences
Siying Lian, Luxi Zhou, Daniel M. Murphy, Karl D. Froyd, Owen B. Toon, Pengfei Yu
Summary: Dust aerosols have a significant impact on the radiative and energy balance at local and global scales. This study improves the simulated size distribution of dust aerosol and finds that North African, Middle Eastern, and Asian dust contribute the most to global dust emissions, with Asian dust dominating the dust mass budget in the upper troposphere and lower stratosphere.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Meteorology & Atmospheric Sciences
Adam T. Ahern, Frank Erdesz, Nicholas L. Wagner, Charles A. Brock, Ming Lyu, Kyra Slovacek, Richard H. Moore, Elizabeth B. Wiggins, Daniel M. Murphy
Summary: This paper presents an improved imaging nephelometer, LiNeph, for measuring the directionality and polarization of light with high temporal resolution. It can be deployed in both airborne and ground-based measurements, and has been verified during the 2019 FIREX-AQ campaign.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(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
Charles A. Brock, Karl D. Froyd, Maximilian Dollner, Christina J. Williamson, Gregory Schill, Daniel M. Murphy, Nicholas J. Wagner, Agnieszka Kupc, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Jason C. Schroder, Douglas A. Day, Derek J. Price, Bernadett Weinzierl, Joshua P. Schwarz, Joseph M. Katich, Siyuan Wang, Linghan Zeng, Rodney Weber, Jack Dibb, Eric Scheuer, Glenn S. Diskin, Joshua P. DiGangi, ThaoPaul Bui, Jonathan M. Dean-Day, Chelsea R. Thompson, Jeff Peischl, Thomas B. Ryerson, Ilann Bourgeois, Bruce C. Daube, Roisin Commane, Steven C. Wofsy
Summary: In situ measurements of aerosol microphysical, chemical, and optical properties were conducted during global-scale flights from 2016-2018 as part of the Atmospheric Tomography Mission (ATom). The data obtained were used to estimate aerosol hygroscopicity, size distributions, and other intensive and extensive aerosol properties, providing valuable insights into atmospheric aerosols and their behavior. By comparing different measurements and calculations, the study showed no substantial bias in the results, demonstrating the reliability and accuracy of the methodology.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Environmental Sciences
Christina J. Williamson, Agnieszka Kupc, Andrew Rollins, Jan Kazil, Karl D. Froyd, Eric A. Ray, Daniel M. Murphy, Gregory P. Schill, Jeff Peischl, Chelsea Thompson, Ilann Bourgeois, B. Ryerson A. Thomas, Glenn S. Diskin, Joshua P. DiGangi, Donald R. Blake, Thao Paul V. Bui, Maximilian Dollner, Bernadett Weinzierl, Charles A. Brock
Summary: Observations in the lowermost stratosphere at mid- and high latitudes reveal a mode of aerosol smaller than 12 nm, as well as elevated levels of SO2, an important precursor for new particle formation and growth. Aircraft emissions are suggested as likely sources of SO2, as well as potential sources of nucleation mode particles that can grow to larger sizes and affect heterogeneous chemistry and aerosol-radiation interactions.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
