Articles | Volume 20, issue 23
Research article 11 Dec 2020
Research article | 11 Dec 2020
Aerosol-enhanced high precipitation events near the Himalayan foothills
Goutam Choudhury et al.
No articles found.
Pragati Rai, Jay G. Slowik, Markus Furger, Imad El Haddad, Suzanne Visser, Yandong Tong, Atinderpal Singh, Günther Wehrle, Varun Kumar, Anna K. Tobler, Deepika Bhattu, Liwei Wang, Dilip Ganguly, Neeraj Rastogi, Ru-Jin Huang, Jaroslaw Necki, Junji Cao, Sachchida N. Tripathi, Urs Baltensperger, and André S. H. Prévôt
Atmos. Chem. Phys., 21, 717–730,Short summary
We present a simple conceptual framework based on elemental size distributions and enrichment factors that allows for a characterization of major sources, site-to-site similarities, and local differences and the identification of key information required for efficient policy development. Absolute concentrations are by far the highest in Delhi, followed by Beijing, and then the European cities.
Matthias Tesche, Peggy Achtert, and Michael C. Pitts
Atmos. Chem. Phys., 21, 505–516,Short summary
We combine spaceborne lidar observations of clouds in the troposphere and stratosphere to assess the outcome of ground-based polar stratospheric cloud (PSC) observations that are often performed at the mercy of tropospheric clouds. We find that the outcome of ground-based lidar measurements of PSCs depends on the location of the measurement. We also provide recommendations regarding the most suitable sites in the Arctic and Antarctic.
Ravi Sahu, Ayush Nagal, Kuldeep Kumar Dixit, Harshavardhan Unnibhavi, Srikanth Mantravadi, Srijith Nair, Yogesh Simmhan, Brijesh Mishra, Rajesh Zele, Ronak Sutaria, Vidyanand Motiram Motghare, Purushottam Kar, and Sachchida Nand Tripathi
Atmos. Meas. Tech., 14, 37–52,Short summary
A unique feature of our low-cost sensor deployment is a swap-out experiment wherein four of the six sensors were relocated to different sites in the two phases. The swap-out experiment is crucial in investigating the efficacy of calibration models when applied to weather and air quality conditions vastly different from those present during calibration. We developed a novel local calibration algorithm based on metric learning that offers stable and accurate calibration performance.
Johannes Quaas, Antti Arola, Brian Cairns, Matthew Christensen, Hartwig Deneke, Annica M. L. Ekman, Graham Feingold, Ann Fridlind, Edward Gryspeerdt, Otto Hasekamp, Zhanqing Li, Antti Lipponen, Po-Lun Ma, Johannes Mülmenstädt, Athanasios Nenes, Joyce E. Penner, Daniel Rosenfeld, Roland Schrödner, Kenneth Sinclair, Odran Sourdeval, Philip Stier, Matthias Tesche, Bastiaan van Diedenhoven, and Manfred Wendisch
Atmos. Chem. Phys., 20, 15079–15099,Short summary
Anthropogenic pollution particles – aerosols – serve as cloud condensation nuclei and thus increase cloud droplet concentration and the clouds' reflection of sunlight (a cooling effect on climate). This Twomey effect is poorly constrained by models and requires satellite data for better quantification. The review summarizes the challenges in properly doing so and outlines avenues for progress towards a better use of aerosol retrievals and better retrievals of droplet concentrations.
Maria Kezoudi, Matthias Tesche, Helen Smith, Alexandra Tsekeri, Holger Baars, Maximilian Dollner, Víctor Estellés, Bernadett Weinzierl, Zbigniew Ulanowski, Detlef Müller, and Vassilis Amiridis
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACP
Karn Vohra, Eloise A. Marais, Shannen Suckra, Louisa Kramer, William J. Bloss, Ravi Sahu, Abhishek Gaur, Sachchida N. Tripathi, Martin Van Damme, Lieven Clarisse, and Pierre-F. Coheur
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
We find satellite observations of atmospheric composition generally reproduce variability in surface air pollution, so we use their long record to estimate air quality trends in major UK and Indian cities. Our trend analysis shows that pollutants targeted with air quality policies have not declined in Delhi and Kanpur, but have in London and Birmingham, with the exception of a recent and dramatic increase in reactive volatile organics in London. Unregulated ammonia has increased only in Delhi.
Liwei Wang, Jay G. Slowik, Nidhi Tripathi, Deepika Bhattu, Pragati Rai, Varun Kumar, Pawan Vats, Rangu Satish, Urs Baltensperger, Dilip Ganguly, Neeraj Rastogi, Lokesh K. Sahu, Sachchida N. Tripathi, and André S. H. Prévôt
Atmos. Chem. Phys., 20, 9753–9770,
Amit Misra, Sachchida Tripathi, Harjinder Sembhi, and Hartmut Boesch
Ann. Geophys. Discuss.,
Preprint under review for ANGEOShort summary
In this work we validated Copernicus Aerosol Monitoring Service (CAMS) derived aerosol optical depth (AOD) at four sites in Indo-Gangetic Basin and used it to study aerosol climatology and trend in AOD at these sites. We find that sulphate AOD has largest influence on total aerosol climatology. Comparison of CAMS AOD with AERONET AOD shows better correlation when aerosol climatology is dominated by coarse particles. Trend analysis shows largest increase in organic matter and least in sea salt.
Tongshu Zheng, Michael H. Bergin, Ronak Sutaria, Sachchida N. Tripathi, Robert Caldow, and David E. Carlson
Atmos. Meas. Tech., 12, 5161–5181,Short summary
Here we present a simultaneous Gaussian process regression (GPR) and linear regression pipeline to calibrate and monitor dense wireless low-cost particulate matter sensor networks (WLPMSNs) on the fly by using all available reference monitors across an area. Our approach can achieve an overall 30 % prediction error at a 24 h scale, can differentiate malfunctioning nodes, and track drift. Our solution can substantially reduce manual labor for managing WLPMSNs and prolong their lifetimes.
Eleni Marinou, Matthias Tesche, Athanasios Nenes, Albert Ansmann, Jann Schrod, Dimitra Mamali, Alexandra Tsekeri, Michael Pikridas, Holger Baars, Ronny Engelmann, Kalliopi-Artemis Voudouri, Stavros Solomos, Jean Sciare, Silke Groß, Florian Ewald, and Vassilis Amiridis
Atmos. Chem. Phys., 19, 11315–11342,Short summary
We assess the feasibility of ground-based and spaceborne lidars to retrieve profiles of cloud-relevant aerosol concentrations and ice-nucleating particles. The retrieved profiles are in good agreement with airborne in situ measurements. Our methodology will be applied to satellite observations in the future so as to provide a global 3D product of cloud-relevant properties.
Matthias Tesche, Alexei Kolgotin, Moritz Haarig, Sharon P. Burton, Richard A. Ferrare, Chris A. Hostetler, and Detlef Müller
Atmos. Meas. Tech., 12, 4421–4437,Short summary
Today, few lidar are capable of triple-wavelength particle linear depolarization ratio (PLDR) measurements. This study is the first systematic investigation of the effect of different choices of PLDR input on the inversion of lidar measurements of mineral dust and dusty mixtures using light scattering by randomly oriented spheroids. We provide recommendations of the most suitable input parameters for use with the applied methodology, based on a relational assessment of the inversion output.
Sung-Kyun Shin, Matthias Tesche, Youngmin Noh, and Detlef Müller
Atmos. Meas. Tech., 12, 3789–3803,Short summary
This study proposes an aerosol-type classification based on parameters from the AErosol RObotic NETwork (AERONET) version 3 level 2.0 inversion product that describe light depolarization and absorption properties of atmospheric particles. We compare our classification with an earlier method and find that the new approach allows for a refined classification of mineral dust that occurs as a mixture with other absorbing aerosols.
Erika Brattich, Encarnación Serrano Castillo, Fabrizio Giulietti, Jean-Baptiste Renard, Sachi N. Tripathi, Kunal Ghosh, Gwenael Berthet, Damien Vignelles, and Laura Tositti
Ann. Geophys., 37, 389–403,Short summary
This paper describes the aerosol measurement setup and results obtained from the BEXUS18 stratospheric balloon within the A5-Unib (Advanced Atmospheric Aerosol Acquisition and Analysis) experiment performed on 10 October 2014 in northern Sweden (Kiruna). The experiment and the results here presented broaden the understanding of the processes linking the presence of charges with particles all over the vertical heights from the ground to the stratosphere.
Chandan Sarangi, Yun Qian, Karl Rittger, Kathryn J. Bormann, Ying Liu, Hailong Wang, Hui Wan, Guangxing Lin, and Thomas H. Painter
Atmos. Chem. Phys., 19, 7105–7128,Short summary
Radiative forcing induced by deposition of light-absorbing particles (LAPs) on snow is an important surface forcing. Here, we have used high-resolution WRF-Chem (coupled with online snow–LAP–radiation model) simulations for 2013–2014 to estimate the spatial variation in LAP-induced snow albedo darkening effect in high-mountain Asia. Significant improvement in simulated LAP–snow properties with use of a higher spatial resolution for the same model configuration is illustrated over this region.
Sung-Kyun Shin, Matthias Tesche, Detlef Müller, and Youngmin Noh
Atmos. Meas. Tech., 12, 607–618,Short summary
We present a methodology to infer the contribution of mineral dust and non-dust aerosol to the absorbing aerosol optical depth (AAOD) of mixed aerosol layers. The method presents an adaptation of a lidar-based aerosol-type separation technique to passive measurements with AERONET sun photometers by using lidar-specific parameters obtained from the AERONET inversion. The findings on BC-related AAOD are compared to CAMS aerosol reanalysis data with promising results for sites in east Asia.
Sung-Kyun Shin, Matthias Tesche, Kwanchul Kim, Maria Kezoudi, Boyan Tatarov, Detlef Müller, and Youngmin Noh
Atmos. Chem. Phys., 18, 12735–12746,Short summary
We investigate lidar-specific parameters inferred from AERONET sun photometer measurements representative of mineral dust from different source regions. We compare our findings to the literature values on the lidar ratio and the particle linear depolarisation ratio. We find changing values for different source regions, which is in agreement with other observations. For longer wavelengths we find values that are in line with lidar observations.
Tongshu Zheng, Michael H. Bergin, Karoline K. Johnson, Sachchida N. Tripathi, Shilpa Shirodkar, Matthew S. Landis, Ronak Sutaria, and David E. Carlson
Atmos. Meas. Tech., 11, 4823–4846,Short summary
Low-cost particulate matter sensors are promising tools for supplementing existing air quality monitoring networks but their performance under field conditions is not well understood. We characterized how well Plantower PMS3003 sensors measure PM2.5 in a wide range of ambient conditions against different reference sensors. When a more precise reference method is used for calibration and proper RH corrections are made, our work suggests PMS3003's can measure PM2.5 within ~ 10 % of ambient values.
Christine A. Shields, Jonathan J. Rutz, Lai-Yung Leung, F. Martin Ralph, Michael Wehner, Brian Kawzenuk, Juan M. Lora, Elizabeth McClenny, Tashiana Osborne, Ashley E. Payne, Paul Ullrich, Alexander Gershunov, Naomi Goldenson, Bin Guan, Yun Qian, Alexandre M. Ramos, Chandan Sarangi, Scott Sellars, Irina Gorodetskaya, Karthik Kashinath, Vitaliy Kurlin, Kelly Mahoney, Grzegorz Muszynski, Roger Pierce, Aneesh C. Subramanian, Ricardo Tome, Duane Waliser, Daniel Walton, Gary Wick, Anna Wilson, David Lavers, Prabhat, Allison Collow, Harinarayan Krishnan, Gudrun Magnusdottir, and Phu Nguyen
Geosci. Model Dev., 11, 2455–2474,Short summary
ARTMIP (Atmospheric River Tracking Method Intercomparison Project) is a community effort with the explicit goal of understanding the uncertainties, and the implications of those uncertainties, in atmospheric river science solely due to detection algorithm. ARTMIP strives to quantify these differences and provide guidance on appropriate algorithmic choices for the science question posed. Project goals, experimental design, and preliminary results are provided.
Brent N. Holben, Jhoon Kim, Itaru Sano, Sonoyo Mukai, Thomas F. Eck, David M. Giles, Joel S. Schafer, Aliaksandr Sinyuk, Ilya Slutsker, Alexander Smirnov, Mikhail Sorokin, Bruce E. Anderson, Huizheng Che, Myungje Choi, James H. Crawford, Richard A. Ferrare, Michael J. Garay, Ukkyo Jeong, Mijin Kim, Woogyung Kim, Nichola Knox, Zhengqiang Li, Hwee S. Lim, Yang Liu, Hal Maring, Makiko Nakata, Kenneth E. Pickering, Stuart Piketh, Jens Redemann, Jeffrey S. Reid, Santo Salinas, Sora Seo, Fuyi Tan, Sachchida N. Tripathi, Owen B. Toon, and Qingyang Xiao
Atmos. Chem. Phys., 18, 655–671,Short summary
Aerosol particles, such as smoke, vary over space and time. This paper describes a series of very high-resolution ground-based aerosol measurement networks and associated studies that contributed new understanding of aerosol processes and detailed comparisons to satellite aerosol validation. Significantly, these networks also provide an opportunity to statistically relate grab samples of an aerosol parameter to companion satellite observations, a step toward air quality assessment from space.
Chandan Sarangi, Sachchida Nand Tripathi, Vijay P. Kanawade, Ilan Koren, and D. Sivanand Pai
Atmos. Chem. Phys., 17, 5185–5204,Short summary
Aerosol-induced perturbations in cloud systems and rainfall are very uncertain. This study provides observational evidence of a robust positive association between aerosol–cloud–rainfall properties over the Indian summer monsoon region. Observed and modeled aerosol–cloud microphysical changes illustrate that cloud invigoration under a high AOD scenario can explain most of the aerosol-associated changes in cloud fraction, cloud top pressure, and surface rainfall over this region.
Amit Misra, Vijay P. Kanawade, and Sachchida Nand Tripathi
Ann. Geophys., 34, 657–671,Short summary
For an accurate understanding of earth climate system, it is necessary to evaluate the performance of the climate models used to perform these simulations. In this work we have examined aerosol optical depths simulated by 17 models by comparing them with satellite-derived aerosol optical depth. Our results indicate the role of dust aerosols and biogeochemistry in the simulation of aerosols by models.
Graydon Snider, Crystal L. Weagle, Kalaivani K. Murdymootoo, Amanda Ring, Yvonne Ritchie, Emily Stone, Ainsley Walsh, Clement Akoshile, Nguyen Xuan Anh, Rajasekhar Balasubramanian, Jeff Brook, Fatimah D. Qonitan, Jinlu Dong, Derek Griffith, Kebin He, Brent N. Holben, Ralph Kahn, Nofel Lagrosas, Puji Lestari, Zongwei Ma, Amit Misra, Leslie K. Norford, Eduardo J. Quel, Abdus Salam, Bret Schichtel, Lior Segev, Sachchida Tripathi, Chien Wang, Chao Yu, Qiang Zhang, Yuxuan Zhang, Michael Brauer, Aaron Cohen, Mark D. Gibson, Yang Liu, J. Vanderlei Martins, Yinon Rudich, and Randall V. Martin
Atmos. Chem. Phys., 16, 9629–9653,Short summary
We examine the chemical composition of fine particulate matter (PM2.5) collected on filters at traditionally undersampled, globally dispersed urban locations. Several PM2.5 chemical components (e.g. ammonium sulfate, ammonium nitrate, and black carbon) vary by more than an order of magnitude between sites while aerosol hygroscopicity varies by a factor of 2. Enhanced anthropogenic dust fractions in large urban areas are apparent from high Zn : Al ratios.
Holger Baars, Thomas Kanitz, Ronny Engelmann, Dietrich Althausen, Birgit Heese, Mika Komppula, Jana Preißler, Matthias Tesche, Albert Ansmann, Ulla Wandinger, Jae-Hyun Lim, Joon Young Ahn, Iwona S. Stachlewska, Vassilis Amiridis, Eleni Marinou, Patric Seifert, Julian Hofer, Annett Skupin, Florian Schneider, Stephanie Bohlmann, Andreas Foth, Sebastian Bley, Anne Pfüller, Eleni Giannakaki, Heikki Lihavainen, Yrjö Viisanen, Rakesh Kumar Hooda, Sérgio Nepomuceno Pereira, Daniele Bortoli, Frank Wagner, Ina Mattis, Lucja Janicka, Krzysztof M. Markowicz, Peggy Achtert, Paulo Artaxo, Theotonio Pauliquevis, Rodrigo A. F. Souza, Ved Prakesh Sharma, Pieter Gideon van Zyl, Johan Paul Beukes, Junying Sun, Erich G. Rohwer, Ruru Deng, Rodanthi-Elisavet Mamouri, and Felix Zamorano
Atmos. Chem. Phys., 16, 5111–5137,Short summary
The findings from more than 10 years of global aerosol lidar measurements with Polly systems are summarized, and a data set of optical properties for specific aerosol types is given. An automated data retrieval algorithm for continuous Polly lidar observations is presented and discussed by means of a Saharan dust advection event in Leipzig, Germany. Finally, a statistic on the vertical aerosol distribution including the seasonal variability at PollyNET locations around the globe is presented.
A. Arola, G. L. Schuster, M. R. A. Pitkänen, O. Dubovik, H. Kokkola, A. V. Lindfors, T. Mielonen, T. Raatikainen, S. Romakkaniemi, S. N. Tripathi, and H. Lihavainen
Atmos. Chem. Phys., 15, 12731–12740,Short summary
There have been relatively few measurement-based estimates for the direct radiative effect of brown carbon so far. This is first time that the direct radiative effect of brown carbon is estimated by exploiting the AERONET-retrieved imaginary indices. We estimated it for four sites in the Indo-Gangetic Plain: Karachi, Lahore, Kanpur and Gandhi College.
P. Zieger, P. P. Aalto, V. Aaltonen, M. Äijälä, J. Backman, J. Hong, M. Komppula, R. Krejci, M. Laborde, J. Lampilahti, G. de Leeuw, A. Pfüller, B. Rosati, M. Tesche, P. Tunved, R. Väänänen, and T. Petäjä
Atmos. Chem. Phys., 15, 7247–7267,Short summary
The effect of water uptake (hygroscopicity) on aerosol light scattering properties is generally lower for boreal aerosol due to the dominance of organic substances. A columnar optical closure study using ground-based and airborne measurements of aerosol optical, chemical and microphysical properties was conducted and the implications and limitations are discussed.
C. Chaudhuri, S. Tripathi, R. Srivastava, and A. Misra
Ann. Geophys., 33, 671–686,Short summary
In this paper a Himalayan cloudburst event is investigated. The conditions of formation, evolution, and triggering mechanisms of this cloudburst are studied, looking at varieties of observed data sets and simulation with the Weather Research and Forecasting (WRF) model. This cloudburst event is attributed to two mesoscale convective systems originating from Madhya Pradesh and Tibet which interacted over Uttarkashi, and under orographic uplifting in the presence of favorable moisture conditions.
G. Snider, C. L. Weagle, R. V. Martin, A. van Donkelaar, K. Conrad, D. Cunningham, C. Gordon, M. Zwicker, C. Akoshile, P. Artaxo, N. X. Anh, J. Brook, J. Dong, R. M. Garland, R. Greenwald, D. Griffith, K. He, B. N. Holben, R. Kahn, I. Koren, N. Lagrosas, P. Lestari, Z. Ma, J. Vanderlei Martins, E. J. Quel, Y. Rudich, A. Salam, S. N. Tripathi, C. Yu, Q. Zhang, Y. Zhang, M. Brauer, A. Cohen, M. D. Gibson, and Y. Liu
Atmos. Meas. Tech., 8, 505–521,Short summary
We have initiated a global network of ground-level monitoring stations to measure concentrations of fine aerosols in urban environments. Our findings include major ions species, total mass, and total scatter at three wavelengths. Results will be used to further evaluate and enhance satellite remote sensing estimates.
M. Tesche, P. Zieger, N. Rastak, R. J. Charlson, P. Glantz, P. Tunved, and H.-C. Hansson
Atmos. Chem. Phys., 14, 7869–7882,
N. Rastak, S. Silvergren, P. Zieger, U. Wideqvist, J. Ström, B. Svenningsson, M. Maturilli, M. Tesche, A. M. L. Ekman, P. Tunved, and I. Riipinen
Atmos. Chem. Phys., 14, 7445–7460,
J. Huttunen, A. Arola, G. Myhre, A. V. Lindfors, T. Mielonen, S. Mikkonen, J. S. Schafer, S. N. Tripathi, M. Wild, M. Komppula, and K. E. J. Lehtinen
Atmos. Chem. Phys., 14, 6103–6110,
M. Michael, A. Yadav, S. N. Tripathi, V. P. Kanawade, A. Gaur, P. Sadavarte, and C. Venkataraman
Geosci. Model Dev. Discuss.,
Revised manuscript not accepted
J.-B. Renard, S. N. Tripathi, M. Michael, A. Rawal, G. Berthet, M. Fullekrug, R. G. Harrison, C. Robert, M. Tagger, and B. Gaubicher
Atmos. Chem. Phys., 13, 11187–11194,
A. Arola, T. F. Eck, J. Huttunen, K. E. J. Lehtinen, A. V. Lindfors, G. Myhre, A. Smirnov, S. N. Tripathi, and H. Yu
Atmos. Chem. Phys., 13, 7895–7901,
J. Wagner, A. Ansmann, U. Wandinger, P. Seifert, A. Schwarz, M. Tesche, A. Chaikovsky, and O. Dubovik
Atmos. Meas. Tech., 6, 1707–1724,
M. Michael, A. Yadav, S. N. Tripathi, V. P. Kanawade, A. Gaur, P. Sadavarte, and C. Venkataraman
Atmos. Chem. Phys. Discuss.,
Revised manuscript has not been submitted
Related subject area
Subject: Aerosols | Research Activity: Remote Sensing | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)Aerosol characteristics at the three poles of the Earth as characterized by Cloud–Aerosol Lidar and Infrared Pathfinder Satellite ObservationsAerosol impacts on warm-cloud microphysics and drizzle in a moderately polluted environmentAtmospheric boundary layer height estimation from aerosol lidar: a new approach based on morphological image processing techniquesLong-term multi-source data analysis about the characteristics of aerosol optical properties and types over AustraliaStatistical aerosol properties associated with fire events from 2002 to 2019 and a case analysis in 2019 over AustraliaObservation of absorbing aerosols above clouds over the south-east Atlantic Ocean from the geostationary satellite SEVIRI – Part 2: Comparison with MODIS and aircraft measurements from the CLARIFY-2017 field campaignFirst validation of GOME-2/MetOp absorbing aerosol height using EARLINET lidar observationsAutomated time–height-resolved air mass source attribution for profiling remote sensing applicationsAerosol type classification analysis using EARLINET multiwavelength and depolarization lidar observationsSatellite retrieval of aerosol combined with assimilated forecastA global analysis of diurnal variability in dust and dust mixture using CATS observationsSatellite-based radiative forcing by light-absorbing particles in snow across the Northern HemisphereConstraining the relationships between aerosol height, aerosol optical depth and total column trace gas measurements using remote sensing and modelsOptical characterization of pure pollen types using a multi-wavelength Raman polarization lidarMeasurement Report: Determination of aerosol vertical features on different timescales over East Asia based on CATS aerosol productsNorth African mineral dust sources: new insights from a combined analysis based on 3D dust aerosol distributions, surface winds and ancillary soil parametersEARLINET observations of Saharan dust intrusions over the northern Mediterranean region (2014–2017): properties and impact on radiative forcingAEROCOM/AEROSAT AAOT & SSA study, part I: evaluation and intercomparison of satellite measurementsElevated dust layers inhibit dissipation of heavy anthropogenic surface air pollutionAerosol radiative effect during the summer 2019 heatwave produced partly by an inter-continental Saharan dust outbreak. 1. Shortwave dust-induced direct impactBiomass burning events measured by lidars in EARLINET – Part 1: Data analysis methodologyStudy on variations in lidar ratios for Shanghai based on Raman lidarAn AeroCom–AeroSat study: intercomparison of satellite AOD datasets for aerosol model evaluationRadiative effects of long-range-transported Saharan air layers as determined from airborne lidar measurementsAerosol particle depolarization ratio at 1565 nm measured with a Halo Doppler lidarImpact of absorbing and non-absorbing aerosols on radiation and low-level clouds over the Southeast Atlantic from co-located satellite observationsAerosol solar radiative forcing near the Taklimakan Desert based on radiative transfer and regional meteorological simulations during the Dust Aerosol Observation-Kashi campaignAn EARLINET early warning system for atmospheric aerosol aviation hazardsOptical properties of Central Asian aerosol relevant for spaceborne lidar applications and aerosol typing at 355 and 532 nmOptical and geometrical aerosol particle properties over the United Arab EmiratesDetermination and climatology of the diurnal cycle of the atmospheric mixing layer height over Beijing 2013–2018: lidar measurements and implications for air pollutionSite representativity of AERONET and GAW remotely sensed aerosol optical thickness and absorbing aerosol optical thickness observationsReducing uncertainties in satellite estimates of aerosol–cloud interactions over the subtropical ocean by integrating vertically resolved aerosol observationsRemote sensing of two exceptional winter aerosol pollution events and representativeness of ground-based measurementsComparison of south-east Atlantic aerosol direct radiative effect over clouds from SCIAMACHY, POLDER and OMI–MODISThe mechanisms and seasonal differences of the impact of aerosols on daytime surface urban heat island effectAn observational study of the effects of aerosols on diurnal variation of heavy rainfall and associated clouds over Beijing–Tianjin–HebeiLong-term profiling of aerosol light extinction, particle mass, cloud condensation nuclei, and ice-nucleating particle concentration over Dushanbe, Tajikistan, in Central AsiaSatellite mapping of PM2.5 episodes in the wintertime San Joaquin Valley: a “static” model using column water vaporImproved 1 km resolution PM2.5 estimates across China using enhanced space–time extremely randomized treesMerging regional and global aerosol optical depth records from major available satellite productsSatellite observations of aerosols and clouds over southern China from 2006 to 2015: analysis of changes and possible interaction mechanismsInterannual variability and trends of combustion aerosol and dust in major continental outflows revealed by MODIS retrievals and CAM5 simulations during 2003–2017Technical note: A simple method for retrieval of dust aerosol optical depth with polarized reflectance over oceansHow should we aggregate data? Methods accounting for the numerical distributions, with an assessment of aerosol optical depthConstraining global aerosol emissions using POLDER/PARASOL satellite remote sensing observationsDetection and characterization of birch pollen in the atmosphere using a multiwavelength Raman polarization lidar and Hirst-type pollen sampler in FinlandDifferent strategies to retrieve aerosol properties at night-time with the GRASP algorithmTwo-dimensional mineral dust radiative effect calculations from CALIPSO observations over EuropeInvestigation of CATS aerosol products and application toward global diurnal variation of aerosols
Yikun Yang, Chuanfeng Zhao, Quan Wang, Zhiyuan Cong, Xingchuan Yang, and Hao Fan
Atmos. Chem. Phys., 21, 4849–4868,Short summary
The occurrence frequency of different aerosol types and aerosol optical depth over the Arctic, Antarctic and Tibetan Plateau (TP) show distinctive spatiotemporal differences. The aerosol extinction coefficient in the Arctic and TP has a broad vertical distribution, while that of the Antarctic has obvious seasonal differences. Compared with the Antarctic, the Arctic and TP are vulnerable to surrounding pollutants, and the source of air masses has obvious seasonal variations.
Ying-Chieh Chen, Sheng-Hsiang Wang, Qilong Min, Sarah Lu, Pay-Liam Lin, Neng-Huei Lin, Kao-Shan Chung, and Everette Joseph
Atmos. Chem. Phys., 21, 4487–4502,Short summary
In this study, we integrate satellite and surface observations to statistically quantify aerosol impacts on low-level warm-cloud microphysics and drizzle over northern Taiwan. Our result provides observational evidence for aerosol indirect effects. The frequency of drizzle is reduced under polluted conditions. For light-precipitation events (≤ 1 mm h-1), however, higher aerosol concentrations drive raindrops toward smaller sizes and thus increase the appearance of the drizzle drops.
Gemine Vivone, Giuseppe D'Amico, Donato Summa, Simone Lolli, Aldo Amodeo, Daniele Bortoli, and Gelsomina Pappalardo
Atmos. Chem. Phys., 21, 4249–4265,Short summary
We developed a methodology to retrieve the atmospheric boundary layer height from elastic and multi-wavelength lidar observations that uses a new approach based on morphological image processing techniques. The intercomparison with other state-of-the-art algorithms shows on average 30 % improved performance. The algorithm also shows excellent performance with respect to the running time, i.e., just few seconds to execute the whole signal processing chain over 72 h of continuous measurements.
Xingchuan Yang, Chuanfeng Zhao, Yikun Yang, and Hao Fan
Atmos. Chem. Phys., 21, 3803–3825,Short summary
We investigate the spatiotemporal distributions of aerosol optical properties and major aerosol types, along with the vertical distribution of the major aerosol types over Australia based on multi-source data. The results of this study provide significant information on aerosol optical properties in Australia, which can help to understand their characteristics and potential climate impacts.
Xingchuan Yang, Chuanfeng Zhao, Yikun Yang, Xing Yan, and Hao Fan
Atmos. Chem. Phys., 21, 3833–3853,Short summary
Using long-term multi-source data, this study shows significant impacts of fire events on aerosol properties over Australia. The contribution of carbonaceous aerosols to the total was 26 % of the annual average but larger (30–43 %) in September–December; smoke and dust are the two dominant aerosol types at different heights in southeastern Australia for the 2019 fire case. These findings are helpful for understanding aerosol climate effects and improving climate modeling in Australia in future.
Fanny Peers, Peter Francis, Steven J. Abel, Paul A. Barrett, Keith N. Bower, Michael I. Cotterell, Ian Crawford, Nicholas W. Davies, Cathryn Fox, Stuart Fox, Justin M. Langridge, Kerry G. Meyer, Steven E. Platnick, Kate Szpek, and Jim M. Haywood
Atmos. Chem. Phys., 21, 3235–3254,Short summary
Satellite observations at high temporal resolution are a valuable asset to monitor the transport of biomass burning plumes and the cloud diurnal cycle in the South Atlantic, but they need to be validated. Cloud and above-cloud aerosol properties retrieved from SEVIRI are compared against MODIS and measurements from the CLARIFY-2017 campaign. While some systematic differences are observed between SEVIRI and MODIS, the overall agreement in the cloud and aerosol properties is very satisfactory.
Konstantinos Michailidis, Maria-Elissavet Koukouli, Nikolaos Siomos, Dimitris Balis, Olaf Tuinder, L. Gijsbert Tilstra, Lucia Mona, Gelsomina Pappalardo, and Daniele Bortoli
Atmos. Chem. Phys., 21, 3193–3213,Short summary
The aim of this study is to investigate the potential of the GOME-2 instrument aboard the MetOp-A, MetOp-B and MetOp-C platforms to deliver accurate geometrical features of lofted aerosol layers. For this purpose, we use archived ground-based data from lidar stations available from the EARLINET database. We show that for this well-developed and spatially well-spread aerosol layer, most GOME-2 retrievals fall within 1 km of the exact temporally collocated lidar observation.
Martin Radenz, Patric Seifert, Holger Baars, Athena Augusta Floutsi, Zhenping Yin, and Johannes Bühl
Atmos. Chem. Phys., 21, 3015–3033,
Maria Mylonaki, Elina Giannakaki, Alexandros Papayannis, Christina-Anna Papanikolaou, Mika Komppula, Doina Nicolae, Nikolaos Papagiannopoulos, Aldo Amodeo, Holger Baars, and Ourania Soupiona
Atmos. Chem. Phys., 21, 2211–2227,Short summary
We introduce an automated aerosol type classification method, SCAN. The output of SCAN is compared with two aerosol classification methods: (1) the Mahalanobis distance automatic aerosol type classification and (2) a neural network aerosol typing algorithm. A total of 97 free tropospheric aerosol layers from four EARLINET stations in the period 2014–2018 were classified.
Mayumi Yoshida, Keiya Yumimoto, Takashi M. Nagao, Taichu Y. Tanaka, Maki Kikuchi, and Hiroshi Murakami
Atmos. Chem. Phys., 21, 1797–1813,Short summary
We developed a new aerosol satellite retrieval algorithm combining a numerical aerosol forecast. This is the first study that utilizes the assimilated model forecast of aerosol as an a priori estimate of the retrieval. Aerosol retrievals were improved by effectively incorporating both model and satellite information. By using the assimilated forecast as an a priori estimate, information from previous observations can be propagated to future retrievals, thus leading to better retrieval accuracy.
Yan Yu, Olga V. Kalashnikova, Michael J. Garay, Huikyo Lee, Myungje Choi, Gregory S. Okin, John E. Yorks, James R. Campbell, and Jared Marquis
Atmos. Chem. Phys., 21, 1427–1447,Short summary
Given the current uncertainties in the simulated diurnal variability of global dust mobilization and concentration, observational characterization of the variations in dust mobilization and concentration will provide a valuable benchmark for evaluating and constraining such model simulations. The current study investigates the diurnal cycle of dust loading across the global tropics, subtropics, and mid-latitudes by analyzing aerosol observations from the International Space Station.
Jiecan Cui, Tenglong Shi, Yue Zhou, Dongyou Wu, Xin Wang, and Wei Pu
Atmos. Chem. Phys., 21, 269–288,Short summary
We make the first quantitative, remote-sensing-based, and hemisphere-scale assessment of radiative forcing (RF) due to light-absorbing particles (LAPs) in snow. We observed significant spatial variations in snow albedo reduction and RF due to LAPs throughout the Northern Hemisphere, with the lowest values occurring in the Arctic and the highest in northeastern China. We determined that the LAPs in snow play a critical role in spatial variability in Northern Hemisphere albedo reduction and RF.
Shuo Wang, Jason Blake Cohen, Chuyong Lin, and Weizhi Deng
Atmos. Chem. Phys., 20, 15401–15426,Short summary
We analyze global measurements of aerosol height from fires. A plume rise model reproduces measurements with a low bias in five regions, while a statistical model based on satellite measurements of trace gasses co-emitted from the fires reproduces measurements without bias in eight regions. We propose that the magnitude of the pollutants emitted may impact their height and subsequent downwind transport. Using satellite data allows better modeling of the global aerosol distribution.
Xiaoxia Shang, Elina Giannakaki, Stephanie Bohlmann, Maria Filioglou, Annika Saarto, Antti Ruuskanen, Ari Leskinen, Sami Romakkaniemi, and Mika Komppula
Atmos. Chem. Phys., 20, 15323–15339,Short summary
Measurements of the multi-wavelength Raman polarization lidar PollyXT have been combined with measurements of pollen type and concentration using a traditional pollen sampler at a rural forest site in Kuopio, Finland. The depolarization ratio was enhanced when there were pollen grains in the atmosphere, illustrating the potential of lidar to track pollen grains in the atmosphere. The depolarization ratio of pure pollen particles was assessed for birch and pine pollen using a novel algorithm.
Yueming Cheng, Tie Dai, Jiming Li, and Guangyu Shi
Atmos. Chem. Phys., 20, 15307–15322,Short summary
In this paper we present the analysis of the aerosol vertical features observed by CATS collected from 2015 to 2017 over three selected regions (North China, the Tibetan Plateau, and the Tarim Basin) over different timescales. This comprehensive information provides insights into the seasonal variations and diurnal cycles of the aerosol vertical features across East Asia.
Sophie Vandenbussche, Sieglinde Callewaert, Kerstin Schepanski, and Martine De Mazière
Atmos. Chem. Phys., 20, 15127–15146,Short summary
Mineral dust aerosols blown mostly from desert areas are a key player in the climate system. We use a new desert dust aerosol low-altitude concentration data set as well as additional information on the surface state and low-altitude winds to infer desert dust emission and source maps over North Africa. With 9 years of data, we observe a full seasonal cycle of dust emissions, differentiating morning and afternoon/evening emissions and providing a first glance at long-term changes.
Ourania Soupiona, Alexandros Papayannis, Panagiotis Kokkalis, Romanos Foskinis, Guadalupe Sánchez Hernández, Pablo Ortiz-Amezcua, Maria Mylonaki, Christina-Anna Papanikolaou, Nikolaos Papagiannopoulos, Stefanos Samaras, Silke Groß, Rodanthi-Elisavet Mamouri, Lucas Alados-Arboledas, Aldo Amodeo, and Basil Psiloglou
Atmos. Chem. Phys., 20, 15147–15166,Short summary
51 dust events over the Mediterranean from EARLINET were studied regarding the aerosol geometrical, optical and microphysical properties and radiative forcing. We found δp532 values of 0.24–0.28, LR532 values of 49–52 sr and AOT532 of 0.11–0.40. The aerosol mixing state was also examined. Depending on the dust properties, intensity and solar zenith angle, the estimated solar radiative forcing ranged from −59 to −22 W m−2 at the surface and from −24 to −1 W m−2 at the TOA (cooling effect).
Nick Schutgens, Oleg Dubovik, Otto Hasekamp, Omar Torres, Hiren Jethva, Peter J. T. Leonard, Pavel Litvinov, Jens Redemann, Yohei Shinozuka, Gerrit de Leeuw, Stefan Kinne, Thomas Popp, Michael Schulz, and Philip Stier
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Absorptive aerosol has a potentially large impact on climate change. We evaluate and intercompare four global satellite datasets of Absorptive Aerosol Optical Depth (AAOD) and Single Scattering Albedo (SSA). We show that these datasets show reasonable correlations with the AERONET reference although significant biases remain. In a follow-up paper we show that these observations nevertheless can be used for model evaluation.
Zhuang Wang, Cheng Liu, Zhouqing Xie, Qihou Hu, Meinrat O. Andreae, Yunsheng Dong, Chun Zhao, Ting Liu, Yizhi Zhu, Haoran Liu, Chengzhi Xing, Wei Tan, Xiangguang Ji, Jinan Lin, and Jianguo Liu
Atmos. Chem. Phys., 20, 14917–14932,Short summary
Significant stratification of aerosols was observed in North China. Polluted dust dominated above the PBL, and anthropogenic aerosols prevailed within the PBL, which is mainly driven by meteorological conditions. The key role of the elevated dust is to alter atmospheric thermodynamics and stability, causing the suppression of turbulence exchange and a decrease in PBL height, especially during the dissipation stage, thereby inhibiting dissipation of persistent heavy surface haze pollution.
Carmen Córdoba-Jabonero, Michaël Sicard, María-Ángeles López-Cayuela, Albert Ansmann, Adolfo Comerón, María-Paz Zorzano, Alejandro Rodríguez-Gómez, and Constantino Muñoz-Pocar
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
The particular pathway of the dust outbreaks defines the aerosol scenario, and hence, the SW direct dust radiative effects (DRE). The synergetic use of POLIPHON method with continuous P-MPL measurements allows evaluating separately the radiative effect of both dust coarse (Dc) and fine (Df) particles. A dust-induced cooling effect is found, and despite Dc usually dominate for intense dust events, the Df contribution to the total DRE can be significant, being higher at the TOA than on surface.
Mariana Adam, Doina Nicolae, Iwona S. Stachlewska, Alexandros Papayannis, and Dimitris Balis
Atmos. Chem. Phys., 20, 13905–13927,Short summary
Biomass burning events measured by EARLINET are analysed using intensive parameters. The pollution layers are labelled smoke layers if fires were found along the air-mass back trajectory. The number of contributing fires to the smoke measurements is quantified. It is shown that most of the time we measure mixed smoke. The methodology provides three research directions: fires measured by several stations, long-range transport from N. America, and an analysis function of continental sources.
Tongqiang Liu, Qianshan He, Yonghang Chen, Jie Liu, Qiong Liu, Wei Gao, Guan Huang, and Wenhao Shi
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACP
Nick Schutgens, Andrew M. Sayer, Andreas Heckel, Christina Hsu, Hiren Jethva, Gerrit de Leeuw, Peter J. T. Leonard, Robert C. Levy, Antti Lipponen, Alexei Lyapustin, Peter North, Thomas Popp, Caroline Poulsen, Virginia Sawyer, Larisa Sogacheva, Gareth Thomas, Omar Torres, Yujie Wang, Stefan Kinne, Michael Schulz, and Philip Stier
Atmos. Chem. Phys., 20, 12431–12457,Short summary
We intercompare 14 different datasets of satellite observations of aerosol. Such measurements are challenging but also provide the best opportunity to globally observe an atmospheric component strongly related to air pollution and climate change. Our study shows that most datasets perform similarly well on a global scale but that locally errors can be quite different. We develop a technique to estimate satellite errors everywhere, even in the absence of surface reference data.
Manuel Gutleben, Silke Groß, Martin Wirth, and Bernhard Mayer
Atmos. Chem. Phys., 20, 12313–12327,Short summary
Airborne lidar measurements in the vicinity of Barbados are used to investigate radiative effects of long-range-transported Saharan air layers. Derived atmospheric heating rates indicate that observed enhanced water vapor concentrations inside these layers are the main drivers for dust vertical mixing inside the layers. Additionally, they may play a major role for the suppression of subjacent convective cloud development.
Ville Vakkari, Holger Baars, Stephanie Bohlmann, Johannes Bühl, Mika Komppula, Rodanthi-Elisavet Mamouri, and Ewan James O'Connor
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Depolarization ratio is a valuable parameter for aerosol categorization from remote sensing measurements. Here, we introduce particle depolarization ratio measurements at 1565 nm wavelength, which is substantially longer than previously utilised wavelengths and enhances our capabilities to study wavelength dependency of particle depolarization ratio.
Alejandro Baró Pérez, Abhay Devasthale, Frida Bender, and Annica M. L. Ekman
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
We study the impacts of biomass burning plumes on radiation and clouds over the Southeast Atlantic using data derived from satellite observations and data-constrained models simulations. A substantial fraction of the aerosols within the plumes is not classified as smoke by the satellite. The atmosphere warms more with increasing smoke aerosol loading, but we find no effect on the clouds. The cloud top radiative cooling decreases weakly with increasing moisture within the overlying aerosol layer.
Li Li, Zhengqiang Li, Wenyuan Chang, Yang Ou, Philippe Goloub, Chengzhe Li, Kaitao Li, Qiaoyun Hu, Jianping Wang, and Manfred Wendisch
Atmos. Chem. Phys., 20, 10845–10864,Short summary
Dust Aerosol Observation-Kashi (DAO-K) campaign was conducted near the Taklimakan Desert in April 2019 to obtain comprehensive aerosol, atmosphere, and surface parameters. Estimations of aerosol solar radiative forcing by a radiative transfer (RT) model were improved based on the measured aerosol parameters, additionally considering atmospheric profiles and diurnal variations of surface albedo. RT simulations agree well with simultaneous irradiance observations, even in dust-polluted conditions.
Nikolaos Papagiannopoulos, Giuseppe D'Amico, Anna Gialitaki, Nicolae Ajtai, Lucas Alados-Arboledas, Aldo Amodeo, Vassilis Amiridis, Holger Baars, Dimitris Balis, Ioannis Binietoglou, Adolfo Comerón, Davide Dionisi, Alfredo Falconieri, Patrick Fréville, Anna Kampouri, Ina Mattis, Zoran Mijić, Francisco Molero, Alex Papayannis, Gelsomina Pappalardo, Alejandro Rodríguez-Gómez, Stavros Solomos, and Lucia Mona
Atmos. Chem. Phys., 20, 10775–10789,Short summary
Volcanic and desert dust particles affect human activities in manifold ways; consequently, mitigation tools are important. Their early detection and the issuance of early warnings are key elements in the initiation of operational response procedures. A methodology for the early warning of these hazards using European Aerosol Research Lidar Network (EARLINET) data is presented. The tailored product is investigated during a volcanic eruption and mineral dust advected in the eastern Mediterranean.
Julian Hofer, Albert Ansmann, Dietrich Althausen, Ronny Engelmann, Holger Baars, Khanneh Wadinga Fomba, Ulla Wandinger, Sabur F. Abdullaev, and Abduvosit N. Makhmudov
Atmos. Chem. Phys., 20, 9265–9280,Short summary
For the first time, a dense data set of particle extinction-to-backscatter ratios (lidar ratios), depolarization ratios, and backscatter- and extinction-related Ångström exponents for a Central Asian site are presented. The observations were performed with a continuously running multiwavelength polarization Raman lidar at Dushanbe, Tajikistan, during an 18-month campaign. The found optical properties reflect the large range of occurring aerosol mixtures.
Maria Filioglou, Elina Giannakaki, John Backman, Jutta Kesti, Anne Hirsikko, Ronny Engelmann, Ewan O'Connor, Jari T. T. Leskinen, Xiaoxia Shang, Hannele Korhonen, Heikki Lihavainen, Sami Romakkaniemi, and Mika Komppula
Atmos. Chem. Phys., 20, 8909–8922,Short summary
Dust optical properties are region-dependent. Saharan, Asian, and Arabian dusts do not pose similar optical properties in terms of lidar ratios; thus, a universal lidar ratio for dust particles will lead to biases. The present study analyses observations over the United Arab Emirates, quantifying the optical and geometrical extents of the aerosol layers in the area, providing at the same time the Arabian dust properties along with chemical analysis of dust samples collected in the region.
Haofei Wang, Zhengqiang Li, Yang Lv, Ying Zhang, Hua Xu, Jianping Guo, and Philippe Goloub
Atmos. Chem. Phys., 20, 8839–8854,Short summary
Lidar shows good performance in calculating the convective layer height in the daytime and the residual layer height at night, as well as having the potential to describe the stable layer height at night. The MLH seasonal change in Beijing indicates that it is low in winter and autumn and high in spring and summer. From 2014 to 2018, the magnitude of the diurnal cycle of MLH increased year by year. MLH from lidar shows better accuracy than a radiosonde when calculating surface pollution.
Nick A. J. Schutgens
Atmos. Chem. Phys., 20, 7473–7488,Short summary
Aerosols are tiny particles in the air that affect human health and climate. To study these particles, measurement networks across the world are used. Each site, however, can only observe the air directly above it, so how representative is this measurement for the wider environment? The sites of a well-known remote sensing network (AERONET) are examined and ranked according to their representativity. This should benefit researchers using this measurement network.
David Painemal, Fu-Lung Chang, Richard Ferrare, Sharon Burton, Zhujun Li, William L. Smith Jr., Patrick Minnis, Yan Feng, and Marian Clayton
Atmos. Chem. Phys., 20, 7167–7177,Short summary
Aerosol–cloud interactions (ACIs) are the most uncertain aspect of anthropogenic forcing. Although satellites provide the observational dataset for the global ACI quantification, retrievals are limited to vertically integrated quantities (e.g., aerosol optical depth – AOD), which are typically used as an aerosol proxy. This study demonstrates that matching vertically resolved aerosol from CALIOP at the cloud-layer height with satellite cloud retrievals reduces uncertainties in ACI estimates.
Alexandre Baron, Patrick Chazette, and Julien Totems
Atmos. Chem. Phys., 20, 6749–6768,Short summary
Two major winter aerosol pollution events have been sampled over the Paris area. They correspond to weather conditions with a high-pressure system. We show that during such events the ground-based particle matter content can be related to lidar-derived aerosol extinction coefficient within the atmospheric planetary boundary layer. This opens a new horizon for the monitoring of intense pollution events from space-borne active sensors.
Martin de Graaf, Ruben Schulte, Fanny Peers, Fabien Waquet, L. Gijsbert Tilstra, and Piet Stammes
Atmos. Chem. Phys., 20, 6707–6723,Short summary
The radiative effect from smoke by wildfires has been found to be much stronger than models predict. The effect is complex; smoke generally cools the climate system by reflecting sunlight but strongly warms the system when it is found over a bright cloud deck. In this paper three different satellite datasets are compared and all three confirm the strong warming of African smoke over the cloud deck in the south-east Atlantic. The intercomparison reduces the uncertainties in the observations.
Wenchao Han, Zhanqing Li, Fang Wu, Yuwei Zhang, Jianping Guo, Tianning Su, Maureen Cribb, Jiwen Fan, Tianmeng Chen, Jing Wei, and Seoung-Soo Lee
Atmos. Chem. Phys., 20, 6479–6493,Short summary
Observational data and model simulation were used to analyze the daytime urban heat island intensity (UHII) under polluted and clean conditions in China. We found that aerosols reduce the UHII in summer but increase the UHII in winter. Two mechanisms, the aerosol radiative effect (ARE) and the aerosol dynamic effect (ADE), behave differently in summer and winter. In summer, the UHII is mainly affected by the ARE, and the ADE is weak, and the opposite is the case in winter.
Siyuan Zhou, Jing Yang, Wei-Chyung Wang, Chuanfeng Zhao, Daoyi Gong, and Peijun Shi
Atmos. Chem. Phys., 20, 5211–5229,Short summary
Aerosol–cloud–precipitation interaction is a challenging problem in regional climate. Our study contrasted the observed diurnal variation of heavy rainfall and associated clouds over Beijing–Tianjin–Hebei between clean and polluted days during the 2002–2012 summers. We found the heavy rainfall under pollution has earlier start time, earlier peak time and longer duration, and further found the absorbing aerosols and scattering aerosols play different roles in the heavy rainfall diurnal variation.
Julian Hofer, Albert Ansmann, Dietrich Althausen, Ronny Engelmann, Holger Baars, Sabur F. Abdullaev, and Abduvosit N. Makhmudov
Atmos. Chem. Phys., 20, 4695–4711,Short summary
For the first time, continuous, vertically resolved long-term aerosol measurements were conducted with a state-of-the-art multiwavelength lidar over a Central Asian site. Such observations are urgently required in efforts to predict future climate and environmental conditions and to support spaceborne remote sensing (ground truth activities).
Robert B. Chatfield, Meytar Sorek-Hamer, Robert F. Esswein, and Alexei Lyapustin
Atmos. Chem. Phys., 20, 4379–4397,Short summary
There is a great need to define health-affecting pollution by small particles as “respirable aerosol”. The wintertime San Joaquin Valley experiences severe episodes that need full maps. A few air pollution monitors are set out by agencies in such regions. Satellite data on haziness and daily calibration using the monitors map out improved pollution estimates for the winter of 2012–2013. These show patterns of valuable empirical information about sources, transport, and cleanout of pollution.
Jing Wei, Zhanqing Li, Maureen Cribb, Wei Huang, Wenhao Xue, Lin Sun, Jianping Guo, Yiran Peng, Jing Li, Alexei Lyapustin, Lei Liu, Hao Wu, and Yimeng Song
Atmos. Chem. Phys., 20, 3273–3289,Short summary
This study introduced an enhanced space–time extremely randomized trees (STET) approach to improve the 1 km resolution ground-level PM2.5 estimates across China using the remote sensing technology. The STET model shows high accuracy and strong predictive power and appears to outperform most models reported by previous studies. Thus, it is of great importance for future air pollution studies at medium- or small-scale areas and will be applied to generate the historical PM2.5 dataset across China.
Larisa Sogacheva, Thomas Popp, Andrew M. Sayer, Oleg Dubovik, Michael J. Garay, Andreas Heckel, N. Christina Hsu, Hiren Jethva, Ralph A. Kahn, Pekka Kolmonen, Miriam Kosmale, Gerrit de Leeuw, Robert C. Levy, Pavel Litvinov, Alexei Lyapustin, Peter North, Omar Torres, and Antti Arola
Atmos. Chem. Phys., 20, 2031–2056,Short summary
The typical lifetime of a single satellite platform is on the order of 5–15 years; thus, for climate studies the usage of multiple satellite sensors should be considered. Here we introduce and evaluate a monthly AOD merged product and AOD global and regional time series for the period 1995–2017 created from 12 individual satellite AOD products, which provide a long-term perspective on AOD changes over different regions of the globe.
Nikos Benas, Jan Fokke Meirink, Karl-Göran Karlsson, Martin Stengel, and Piet Stammes
Atmos. Chem. Phys., 20, 457–474,Short summary
In this study we analyse aerosol and cloud changes over southern China from 2006 to 2015 and investigate their possible interaction mechanisms. Results show decreasing aerosol loads and increasing liquid cloud cover in late autumn. Further analysis based on various satellite data sets shows consistency with the aerosol semi-direct effect, whereby less absorbing aerosols in the cloud layer would lead to an overall decrease in the evaporation of cloud droplets, thus increasing cloud amount.
Hongbin Yu, Yang Yang, Hailong Wang, Qian Tan, Mian Chin, Robert C. Levy, Lorraine A. Remer, Steven J. Smith, Tianle Yuan, and Yingxi Shi
Atmos. Chem. Phys., 20, 139–161,Short summary
Emissions and long-range transport of mineral dust and combustion-related aerosol from burning fossil fuels and biomass vary from year to year, driven by the evolution of the economy and changes in meteorological conditions and environmental regulations. This study offers both satellite and model perspectives on interannual variability and possible trends in combustion aerosol and dust in major continental outflow regions over the past 15 years (2003–2017).
Wenbo Sun, Yongxiang Hu, Rosemary R. Baize, Gorden Videen, Sungsoo S. Kim, Young-Jun Choi, Kyungin Kang, Chae Kyung Sim, Minsup Jeong, Ali Omar, Snorre A. Stamnes, David G. MacDonnell, and Evgenij Zubko
Atmos. Chem. Phys., 19, 15583–15586,Short summary
Dusts have a significant impact on climate and environment. Detecting dust using satellite instruments is generally conducted by measuring at multiple observation angles due to the uncertainty of the surface reflection. This report shows that the degree of polarization of reflected light can be used for retrieving the optical depth of dust at backscatter angles only, regardless of surface conditions. This simple method is suitable for surveying dust aerosols over oceans with low-cost satellites.
Andrew M. Sayer and Kirk D. Knobelspiesse
Atmos. Chem. Phys., 19, 15023–15048,Short summary
Data about the Earth are routinely obtained from satellite observations, model simulations, and ground-based or other measurements. These are at different space and timescales, and it is common to average them to reduce gaps and increase ease of use. The question of how the data should be averaged depends on the underlying distribution of the quantity. This study presents a method for determining how to appropriately aggregate data and applies it to data sets about atmospheric aerosol levels.
Cheng Chen, Oleg Dubovik, Daven K. Henze, Mian Chin, Tatyana Lapyonok, Gregory L. Schuster, Fabrice Ducos, David Fuertes, Pavel Litvinov, Lei Li, Anton Lopatin, Qiaoyun Hu, and Benjamin Torres
Atmos. Chem. Phys., 19, 14585–14606,Short summary
Global BC, OC and DD aerosol emissions are inverted from POLDER/PARASOL observations for the year 2010 based on the GEOS-Chem inverse modeling framework. The retrieved emissions are 18.4 Tg yr−1 BC, 109.9 Tg yr−1 OC and 731.6 Tg yr−1 DD, which indicate an increase of 166.7 % for BC and 184.0 % for OC, while a decrease of 42.4 % for DD with respect to GEOS-Chem a priori emission inventories is seen. Global annul mean AOD and AAOD resulting from retrieved emissions are 0.119 and 0.0071 at 550 nm.
Stephanie Bohlmann, Xiaoxia Shang, Elina Giannakaki, Maria Filioglou, Annika Saarto, Sami Romakkaniemi, and Mika Komppula
Atmos. Chem. Phys., 19, 14559–14569,Short summary
Measurements of the multiwavelength Raman polarization lidar PollyXT have been combined with measurements of pollen type and concentration using a traditional pollen sampler at the rural forest site in Vehmasmäki, Finland. High particle depolarization ratios were observed during an intense pollination event of birch pollen occasionally mixed with spruce pollen. Our observations illustrate the potential of the particle depolarization ratio to track pollen grains in the atmosphere.
Jose Antonio Benavent-Oltra, Roberto Román, Juan Andrés Casquero-Vera, Daniel Pérez-Ramírez, Hassan Lyamani, Pablo Ortiz-Amezcua, Andrés Esteban Bedoya-Velásquez, Gregori de Arruda Moreira, África Barreto, Anton Lopatin, David Fuertes, Milagros Herrera, Benjamin Torres, Oleg Dubovik, Juan Luis Guerrero-Rascado, Philippe Goloub, Francisco Jose Olmo-Reyes, and Lucas Alados-Arboledas
Atmos. Chem. Phys., 19, 14149–14171,Short summary
In this paper, we use the GRASP algorithm combining different remote-sensing measurements to obtain the aerosol vertical and column properties, both during the day and at night-time. The column properties are compared with AERONET products, and the vertical properties retrieved by GRASP are compared with in situ measurements at high-altitude stations. As an originality, we proposed three new schemes to retrieve the night-time aerosol properties.
Maria José Granados-Muñoz, Michaël Sicard, Nikolaos Papagiannopoulos, Rubén Barragán, Juan Antonio Bravo-Aranda, and Doina Nicolae
Atmos. Chem. Phys., 19, 13157–13173,Short summary
The use of satellite data is of great interest for the determination of aerosol radiative forcing at regional or even global scales, as previous studies in the literature are predominantly only valid locally. A methodology to retrieve 2-D dust radiative effects with large spatial and temporal coverage based on combined satellite data from CALIPSO, MODIS and CERES is presented and evaluated against well-established methods based on ground-based lidar measurements, obtaining quite good results.
Logan Lee, Jianglong Zhang, Jeffrey S. Reid, and John E. Yorks
Atmos. Chem. Phys., 19, 12687–12707,Short summary
The study of the diurnal variation of aerosol optical depth (AOD) and aerosol vertical distribution is necessary for the monitoring and modeling of aerosol particles for various air pollution, visibility and climate-related studies. Upon evaluating 1064 nm AOD and aerosol extinction profiles from the Cloud-Aerosol Transport System (CATS) level 2 aerosol product, we studied the diurnal variation of AOD and aerosol extinction profiles on both regional and global scales.
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This study uses 17 years (2001–2017) of observed rain rate, aerosol optical depth (AOD), meteorological reanalysis fields and outgoing long-wave radiation to investigate high precipitation events at the foothills of the Himalayas. Composite analysis of all data sets for high precipitation events (daily rainfall > 95th percentile) indicates clear and robust associations between high precipitation events, high aerosol loading and high moist static energy values.
This study uses 17 years (2001–2017) of observed rain rate, aerosol optical depth (AOD),...