Articles | Volume 5, issue 7 
            
                
                    
            
            
            https://doi.org/10.5194/amt-5-1761-2012
                    © Author(s) 2012. This work is distributed under 
the Creative Commons Attribution 3.0 License.
                the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/amt-5-1761-2012
                    © Author(s) 2012. This work is distributed under 
the Creative Commons Attribution 3.0 License.
                the Creative Commons Attribution 3.0 License.
Global and regional evaluation of over-land spectral aerosol optical depth retrievals from SeaWiFS
A. M. Sayer
                                            Goddard Earth Sciences Technology And Research (GESTAR), Universities Space Research Association (USRA), Columbia, Maryland, USA
                                        
                                    
                                            NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
                                        
                                    N. C. Hsu
                                            NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
                                        
                                    C. Bettenhausen
                                            NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
                                        
                                    
                                            Science Systems Applications Inc., Lanham, Maryland, USA
                                        
                                    M.-J. Jeong
                                            Department of Atmospheric and Environmental Sciences, Gangneung-Wonju National University, Gangneung, Gangwon-do, Korea
                                        
                                    B. N. Holben
                                            NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
                                        
                                    J. Zhang
                                            Department of Atmospheric Sciences, University of North Dakota, Grand Forks, North Dakota, USA
                                        
                                    Related subject area
            Subject: Aerosols | Technique: Remote Sensing | Topic: Validation and Intercomparisons
            
                    
                        
                            
                            
                                     
                                Aerosol optical property measurement using the orbiting high-spectral-resolution lidar on board the DQ-1 satellite: retrieval and validation
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Regional validation of the solar irradiance tool SolaRes in clear-sky conditions, with a focus on the aerosol module
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                An empirical characterization of the aerosol Ångström exponent interpolation bias using SAGE III/ISS data
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Retrievals of aerosol optical depth over the western North Atlantic Ocean during ACTIVATE
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Characterization of dust aerosols from ALADIN and CALIOP measurements
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Evaluation of Aeolus feature mask and particle extinction coefficient profile products using CALIPSO data
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Lidar depolarization characterization using a reference system
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Assessment of NO2 uncertainty impact on aerosol optical depth retrievals at a global scale
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Improved Mean Field Estimates of GEMS AOD L3 Product: Using Spatio-temporal Variability
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Algorithm evaluation for polarimetric remote sensing of atmospheric aerosols
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Validation of initial observation from the first spaceborne high-spectral-resolution lidar with a ground-based lidar network
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Ozone and aerosol optical depth retrievals using the ultraviolet multi-filter rotating shadow-band radiometer
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Evaluation of “on site” calibration procedures for sun-sky photometers
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Expanding the coverage of Multi-angle Imaging SpectroRadiometer (MISR) aerosol retrievals over shallow, turbid, and eutrophic waters
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Aerosol properties derived from ground-based Fourier transform spectra within the COllaborative Carbon Column Observing Network
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Spectral aerosol optical depth from SI-traceable spectral solar irradiance measurements
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Quality assessment of aerosol lidars at 1064 nm in the framework of the MEMO campaign
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Satellite-based, top-down approach for the adjustment of aerosol precursor emissions over East Asia: the TROPOspheric Monitoring Instrument (TROPOMI) NO2 product and the Geostationary Environment Monitoring Spectrometer (GEMS) aerosol optical depth (AOD) data fusion product and its proxy
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Assessment of severe aerosol events from NASA MODIS and VIIRS aerosol products for data assimilation and climate continuity
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                First assessment of Aeolus Standard Correct Algorithm particle backscatter coefficient retrievals in the eastern Mediterranean
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Remote sensing of aerosol water fraction, dry size distribution and soluble fraction using multi-angle, multi-spectral polarimetry
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Estimates of remote sensing retrieval errors by the GRASP algorithm: application to ground-based observations, concept and validation
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Sensitivity of aerosol optical depth trends using long-term measurements of different sun photometers
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Extended validation and evaluation of the OLCI–SLSTR SYNERGY aerosol product (SY_2_AOD) on Sentinel-3
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Performance evaluation for retrieving aerosol optical depth from the Directional Polarimetric Camera (DPC) based on the GRASP algorithm
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Assessment of tropospheric CALIPSO Version 4.2 aerosol types over the ocean using independent CALIPSO–SODA lidar ratios
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Real-time UV index retrieval in Europe using Earth observation-based techniques: system description and quality assessment
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Evaluation of UV–visible MAX-DOAS aerosol profiling products by comparison with ceilometer, sun photometer, and in situ observations in Vienna, Austria
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Experimental assessment of a micro-pulse lidar system in comparison with reference lidar measurements for aerosol optical properties retrieval
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Characterization of aerosol size properties from measurements of spectral optical depth: a global validation of the GRASP-AOD code using long-term AERONET data
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Retrieval of aerosol fine-mode fraction over China from satellite multiangle polarized observations: validation and comparison
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Retrieval and evaluation of tropospheric-aerosol extinction profiles using multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements over Athens, Greece
                                
                            
                        
                    
                    
                        
                            
                            
                                     
                                Empirically derived parameterizations of the direct aerosol radiative effect based on ORACLES aircraft observations
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                TROPOMI aerosol products: evaluation and observations of synoptic-scale carbonaceous aerosol plumes during 2018–2020
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Combining low-cost, surface-based aerosol monitors with size-resolved satellite data for air quality applications
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Interannual and seasonal variations in the aerosol optical depth of the atmosphere in two regions of Spitsbergen (2002–2018)
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Evaluation of UV aerosol retrievals from an ozone lidar
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Aerosol data assimilation in the MOCAGE chemical transport model during the TRAQA/ChArMEx campaign: lidar observations
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Application of low-cost fine particulate mass monitors to convert satellite aerosol optical depth to surface concentrations in North America and Africa
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Evaluation of the OMPS/LP stratospheric aerosol extinction product using SAGE III/ISS observations
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                A fast visible-wavelength 3D radiative transfer model for numerical weather prediction visualization and forward modeling
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                A first comparison of TROPOMI aerosol layer height (ALH) to CALIOP data
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                The 2018 fire season in North America as seen by TROPOMI: aerosol layer height intercomparisons and evaluation of model-derived plume heights
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Evaluation of satellite-based aerosol datasets and the CAMS reanalysis over the ocean utilizing shipborne reference observations
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Aerosol and cloud top height information of Envisat MIPAS measurements
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Assessment of urban aerosol pollution over the Moscow megacity by the MAIAC aerosol product
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Aerosol retrievals from different polarimeters during the ACEPOL campaign using a common retrieval algorithm
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                A review and framework for the evaluation of pixel-level uncertainty estimates in satellite aerosol remote sensing
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Analysis of global three-dimensional aerosol structure with spectral radiance matching
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                A comparative evaluation of Aura-OMI and SKYNET near-UV single-scattering albedo products
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
            
        
        Chenxing Zha, Lingbing Bu, Zhi Li, Qin Wang, Ahmad Mubarak, Pasindu Liyanage, Jiqiao Liu, and Weibiao Chen
                                    Atmos. Meas. Tech., 17, 4425–4443, https://doi.org/10.5194/amt-17-4425-2024, https://doi.org/10.5194/amt-17-4425-2024, 2024
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                                                China has launched the atmospheric environment monitoring satellite DQ-1, which consists of an advanced lidar system. Our research presents a retrieval algorithm of the DQ-1 lidar system, and the retrieval results are consistent with other datasets. We also use the DQ-1 dataset to investigate dust and volcanic aerosols. This research shows that the DQ-1 lidar system can accurately measure the Earth's atmosphere and has potential for scientific applications.
                                            
                                            
                                        Thierry Elias, Nicolas Ferlay, Gabriel Chesnoiu, Isabelle Chiapello, and Mustapha Moulana
                                    Atmos. Meas. Tech., 17, 4041–4063, https://doi.org/10.5194/amt-17-4041-2024, https://doi.org/10.5194/amt-17-4041-2024, 2024
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                                                In the solar energy application field, it is key to simulate solar resources anywhere on the globe. We conceived the Solar Resource estimate (SolaRes) tool to provide precise and accurate estimates of solar resources for any solar plant technology. We present the validation of SolaRes by comparing estimates with measurements made on two ground-based platforms in northern France for 2 years at 1 min resolution. Validation is done in clear-sky conditions where aerosols are the main factors.
                                            
                                            
                                        Robert P. Damadeo, Viktoria F. Sofieva, Alexei Rozanov, and Larry W. Thomason
                                    Atmos. Meas. Tech., 17, 3669–3678, https://doi.org/10.5194/amt-17-3669-2024, https://doi.org/10.5194/amt-17-3669-2024, 2024
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                                                Comparing different aerosol data sets for scientific studies often requires converting aerosol extinction data between different wavelengths. A common approximation for the spectral behavior of aerosol is the Ångström formula; however, this introduces biases. Using measurements across many different wavelengths from a single instrument, we derive an empirical relationship to both characterize this bias and offer a correction for other studies that may employ this analysis approach.
                                            
                                            
                                        Leong Wai Siu, Joseph S. Schlosser, David Painemal, Brian Cairns, Marta A. Fenn, Richard A. Ferrare, Johnathan W. Hair, Chris A. Hostetler, Longlei Li, Mary M. Kleb, Amy Jo Scarino, Taylor J. Shingler, Armin Sorooshian, Snorre A. Stamnes, and Xubin Zeng
                                    Atmos. Meas. Tech., 17, 2739–2759, https://doi.org/10.5194/amt-17-2739-2024, https://doi.org/10.5194/amt-17-2739-2024, 2024
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                                                An unprecedented 3-year aerosol dataset was collected from a recent NASA field campaign over the western North Atlantic Ocean, which offers a special opportunity to evaluate two state-of-the-art remote sensing instruments, one lidar and the other polarimeter, on the same aircraft. Special attention has been paid to validate aerosol optical depth data and their uncertainties when no reference dataset is available.  Physical reasons for the disagreement between two instruments are discussed.
                                            
                                            
                                        Rui Song, Adam Povey, and Roy G. Grainger
                                    Atmos. Meas. Tech., 17, 2521–2538, https://doi.org/10.5194/amt-17-2521-2024, https://doi.org/10.5194/amt-17-2521-2024, 2024
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                                                In our study, we explored aerosols, tiny atmospheric particles affecting the Earth's climate. Using data from two lidar-equipped satellites, ALADIN and CALIOP, we examined a 2020 Saharan dust event. The newer ALADIN's results aligned with CALIOP's. By merging their data, we corrected CALIOP's discrepancies, enhancing the dust event depiction. This underscores the significance of advanced satellite instruments in aerosol research. Our findings pave the way for upcoming satellite missions.
                                            
                                            
                                        Ping Wang, David Patrick Donovan, Gerd-Jan van Zadelhoff, Jos de Kloe, Dorit Huber, and Katja Reissig
                                        EGUsphere, https://doi.org/10.5194/egusphere-2024-731, https://doi.org/10.5194/egusphere-2024-731, 2024
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                                                We describe the new feature mask (AEL-FM) and aerosol profile retrieval (AEL-PRO) algorithms developed for Aeolus lidar and present the evaluation of the Aeolus products using CALIPSO data for dust aerosols over Africa. We have found that Aeolus and CALIPSO show similar aerosol patterns in the collocated orbits and have good agreement for the extinction coefficients for the dust aerosols, especially for the cloud-free scenes. The finding is applicable to Aeolus L2A product Baseline 17.
                                            
                                            
                                        Alkistis Papetta, Franco Marenco, Maria Kezoudi, Rodanthi-Elisavet Mamouri, Argyro Nisantzi, Holger Baars, Ioana Elisabeta Popovici, Philippe Goloub, Stéphane Victori, and Jean Sciare
                                    Atmos. Meas. Tech., 17, 1721–1738, https://doi.org/10.5194/amt-17-1721-2024, https://doi.org/10.5194/amt-17-1721-2024, 2024
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                                                We propose a method to determine depolarization parameters using observations from a reference instrument at a nearby location, needed for systems where a priori knowledge of cross-talk parameters is not available. It uses three-parameter equations to compare VDR between two co-located lidars at dust and molecular layers. It can be applied retrospectively to existing data acquired during campaigns. Its application to Cimel CE376 corrected VDR bias at high- and low-depolarizing layers.
                                            
                                            
                                        Akriti Masoom, Stelios Kazadzis, Masimo Valeri, Ioannis-Panagiotis Raptis, Gabrielle Brizzi, Kyriakoula Papachristopoulou, Francesca Barnaba, Stefano Casadio, Axel Kreuter, and Fabrizio Niro
                                        EGUsphere, https://doi.org/10.5194/egusphere-2024-682, https://doi.org/10.5194/egusphere-2024-682, 2024
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                                                Aerosols have a wide impact on climate, radiative forcing and human health which are widely represented by aerosol optical depth (AOD). AOD retrievals require Rayleigh scattering and atmospheric absorption (e.g., ozone, NO2, etc.) corrections. This work analyses NO2 (which has high spatiotemporal variation) uncertainty impact on AOD retrievals using the synergy of co-located ground-based instruments with long-term dataset at a global scale and found significant AOD over- or under- estimations.
                                            
                                            
                                        Sooyon Kim, Yeseul Cho, Hanjeong Ki, Seyoung Park, Dagun Oh, Seungjun Lee, Yeonghye Cho, Jhoon Kim, Wonjin Lee, Jaewoo Park, Ick Hoon Jin, and Sangwook Kang
                                        EGUsphere, https://doi.org/10.5194/egusphere-2024-604, https://doi.org/10.5194/egusphere-2024-604, 2024
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                                                The manuscript describes new work that improves the processing of GEMS AOD data by adding a better weighting algorithm with quality flags that was tested in simulations and a new spatio-temporal merging method that helps us learn more about how aerosols affect health and the climate.
                                            
                                            
                                        Otto Hasekamp, Pavel Litvinov, Guangliang Fu, Cheng Chen, and Oleg Dubovik
                                    Atmos. Meas. Tech., 17, 1497–1525, https://doi.org/10.5194/amt-17-1497-2024, https://doi.org/10.5194/amt-17-1497-2024, 2024
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                                                Aerosols are particles in the atmosphere that cool the climate by reflecting and absorbing sunlight (direct effect) and changing cloud properties (indirect effect). The scale of aerosol cooling is uncertain, hampering accurate climate predictions. We compare two algorithms for the retrieval of aerosol properties from multi-angle polarimetric measurements: Generalized Retrieval of Atmosphere and Surface Properties (GRASP) and Remote sensing of Trace gas and Aerosol Products (RemoTAP).
                                            
                                            
                                        Qiantao Liu, Zhongwei Huang, Jiqiao Liu, Weibiao Chen, Qingqing Dong, Songhua Wu, Guangyao Dai, Meishi Li, Wuren Li, Ze Li, Xiaodong Song, and Yuan Xie
                                    Atmos. Meas. Tech., 17, 1403–1417, https://doi.org/10.5194/amt-17-1403-2024, https://doi.org/10.5194/amt-17-1403-2024, 2024
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                                                The achieved results revealed that the ACDL observations were in good agreement with the ground-based lidar measurements during dust events. The heights of cloud top and bottom from these two measurements were well matched and comparable. This study proves that the ACDL provides reliable observations of aerosol and cloud in the presence of various climatic conditions, which helps to further evaluate the impacts of aerosol on climate and the environment, as well as on the ecosystem in the future.
                                            
                                            
                                        Joseph Michalsky and Glen McConville
                                    Atmos. Meas. Tech., 17, 1017–1022, https://doi.org/10.5194/amt-17-1017-2024, https://doi.org/10.5194/amt-17-1017-2024, 2024
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                                                The ozone in the atmosphere is measured by looking at the sun and measuring how diminished the light in the ultraviolet is relative to how bright it is above the Earth's atmosphere. This typically uses spectral instruments that are either costly or no longer manufactured. This paper uses a relatively inexpensive interference filter instrument to perform the same task. Daily ozone measurements with the latter and this filter instrument are compared. Aerosols are calculated as a by-product.
                                            
                                            
                                        Monica Campanelli, Victor Estelles, Gaurav Kumar, Teruyuki Nakajima, Masahiro Momoi, Julian Gröbner, Stelios Kazadzis, Natalia Kouremeti, Angelos Karanikolas, Africa Barreto, Saulius Nevas, Kerstin Schwind, Phillipp Schneider, Iiro Harju, Petri Kärhä, Henri Diémoz, Rei Kudo, Akihiro Uchiyama, Akihiro Yamazaki, Anna Maria Iannarelli, Gabriele Mevi, Annalisa Di Bernardino, and Stefano Casadio
                                        Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2023-165, https://doi.org/10.5194/amt-2023-165, 2023
                                    Revised manuscript accepted for AMT 
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                                                To retrieve columnar aerosol properties from sun-photometers some calibrations factors are needed. The on-site calibrations, performed as frequently as possible to monitor change of the machine condition, allow operators to track and evaluate the calibration status on a continuous basis, reducing the data gaps incurred by the periodical shipments for performing centralized calibrations . The performance of the on-site calibration procedures was evaluated providing very good results.
                                            
                                            
                                        Robert R. Nelson, Marcin L. Witek, Michael J. Garay, Michael A. Bull, James A. Limbacher, Ralph A. Kahn, and David J. Diner
                                    Atmos. Meas. Tech., 16, 4947–4960, https://doi.org/10.5194/amt-16-4947-2023, https://doi.org/10.5194/amt-16-4947-2023, 2023
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                                                Shallow and coastal waters are nutrient-rich and turbid due to runoff. They are also located in areas where the atmosphere has more aerosols than open-ocean waters. NASA's Multi-angle Imaging SpectroRadiometer (MISR) has been monitoring aerosols for over 23 years but does not report results over shallow waters. We developed a new algorithm that uses all four of MISR’s bands and considers light leaving water surfaces. This algorithm performs well and increases over-water measurements by over 7 %.
                                            
                                            
                                        Óscar Alvárez, África Barreto, Omaira E. García, Frank Hase, Rosa D. García, Julian Gröbner, Sergio F. León-Luis, Eliezer Sepúlveda, Virgilio Carreño, Antonio Alcántara, Ramón Ramos, A. Fernando Almansa, Stelios Kazadzis, Noémie Taquet, Carlos Toledano, and Emilio Cuevas
                                    Atmos. Meas. Tech., 16, 4861–4884, https://doi.org/10.5194/amt-16-4861-2023, https://doi.org/10.5194/amt-16-4861-2023, 2023
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                                                In this work, we have extended the capabilities of a portable Fourier transform infrared (FTIR) instrument, which was originally designed to provide high-quality greenhouse gas monitoring within COCCON (COllaborative Carbon Column Observing Network). The extension allows the spectrometer to now also provide coincidentally column-integrated aerosol information. This addition of a reference instrument to a global network will be utilised to enhance our understanding of atmospheric chemistry.
                                            
                                            
                                        Julian Gröbner, Natalia Kouremeti, Gregor Hülsen, Ralf Zuber, Mario Ribnitzky, Saulius Nevas, Peter Sperfeld, Kerstin Schwind, Philipp Schneider, Stelios Kazadzis, África Barreto, Tom Gardiner, Kavitha Mottungan, David Medland, and Marc Coleman
                                    Atmos. Meas. Tech., 16, 4667–4680, https://doi.org/10.5194/amt-16-4667-2023, https://doi.org/10.5194/amt-16-4667-2023, 2023
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                                                Spectral solar irradiance measurements traceable to the International System of Units (SI) allow for intercomparability between instruments and for their validation according to metrological standards. Here we also validate and reduce the uncertainties of the top-of-atmosphere TSIS-1 Hybrid Solar Reference Spectrum (HSRS). The management of large networks, e.g. AERONET or GAW-PFR, will benefit from reducing logistical overhead, improving their resilience and achieving metrological traceability.
                                            
                                            
                                        Longlong Wang, Zhenping Yin, Zhichao Bu, Anzhou Wang, Song Mao, Yang Yi, Detlef Müller, Yubao Chen, and Xuan Wang
                                    Atmos. Meas. Tech., 16, 4307–4318, https://doi.org/10.5194/amt-16-4307-2023, https://doi.org/10.5194/amt-16-4307-2023, 2023
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                                                We report the lidar inter-comparison results with a reference lidar at 1064 nm, in order to homogenize the signals provided by different lidar systems for establishing a  lidar network in China. The profiles of relative deviation of lidar signals are less than 5 % within 500–2000 m and 10 % within 2000–5000 m, increasing confidence in the reliability of the signals provided by each lidar system in the channels at 1064 nm for a future lidar network in China.
                                            
                                            
                                        Jincheol Park, Jia Jung, Yunsoo Choi, Hyunkwang Lim, Minseok Kim, Kyunghwa Lee, Yun Gon Lee, and Jhoon Kim
                                    Atmos. Meas. Tech., 16, 3039–3057, https://doi.org/10.5194/amt-16-3039-2023, https://doi.org/10.5194/amt-16-3039-2023, 2023
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                                                In response to the recent release of new geostationary platform-derived observational data generated by the Geostationary Environment Monitoring Spectrometer (GEMS) and its sister instruments, this study utilized the GEMS data fusion product and its proxy data in adjusting aerosol precursor emissions over East Asia. The use of spatiotemporally more complete observation references in updating the emissions resulted in more promising model performances in estimating aerosol loadings in East Asia.
                                            
                                            
                                        Amanda Gumber, Jeffrey S. Reid, Robert E. Holz, Thomas F. Eck, N. Christina Hsu, Robert C. Levy, Jianglong Zhang, and Paolo Veglio
                                    Atmos. Meas. Tech., 16, 2547–2573, https://doi.org/10.5194/amt-16-2547-2023, https://doi.org/10.5194/amt-16-2547-2023, 2023
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                                                The purpose of this study is to create and evaluate a gridded dataset composed of multiple satellite instruments and algorithms to be used for data assimilation. An important part of aerosol data assimilation is having consistent measurements, especially for severe aerosol events. This study evaluates 4 years of data from MODIS, VIIRS, and AERONET with a focus on aerosol severe event detection from a regional and global perspective.
                                            
                                            
                                        Antonis Gkikas, Anna Gialitaki, Ioannis Binietoglou, Eleni Marinou, Maria Tsichla, Nikolaos Siomos, Peristera Paschou, Anna Kampouri, Kalliopi Artemis Voudouri, Emmanouil Proestakis, Maria Mylonaki, Christina-Anna Papanikolaou, Konstantinos Michailidis, Holger Baars, Anne Grete Straume, Dimitris Balis, Alexandros Papayannis, Tomasso Parrinello, and Vassilis Amiridis
                                    Atmos. Meas. Tech., 16, 1017–1042, https://doi.org/10.5194/amt-16-1017-2023, https://doi.org/10.5194/amt-16-1017-2023, 2023
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                                                We perform an assessment analysis of the Aeolus Standard Correct Algorithm (SCA) backscatter coefficient retrievals against reference observations acquired at three Greek lidar stations (Athens, Thessaloniki and Antikythera) of the PANACEA network. Overall, 43 cases are analysed, whereas specific aerosol scenarios in the vicinity of Antikythera island (SW Greece) are emphasised. All key Cal/Val aspects and recommendations, and the ongoing related activities, are thoroughly discussed.
                                            
                                            
                                        Bastiaan van Diedenhoven, Otto P. Hasekamp, Brian Cairns, Gregory L. Schuster, Snorre Stamnes, Michael Shook, and Luke Ziemba
                                    Atmos. Meas. Tech., 15, 7411–7434, https://doi.org/10.5194/amt-15-7411-2022, https://doi.org/10.5194/amt-15-7411-2022, 2022
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                                                The strong variability in the chemistry of atmospheric particulate matter affects the amount of water aerosols absorb and their effect on climate. We present a remote sensing method to determine the amount of water in particulate matter. Its application to airborne instruments indicates that the observed aerosols have rather low water contents and low fractions of soluble particles. Future satellites will be able to yield global aerosol water uptake data.
                                            
                                            
                                        Milagros E. Herrera, Oleg Dubovik, Benjamin Torres, Tatyana Lapyonok, David Fuertes, Anton Lopatin, Pavel Litvinov, Cheng Chen, Jose Antonio Benavent-Oltra, Juan L. Bali, and Pablo R. Ristori
                                    Atmos. Meas. Tech., 15, 6075–6126, https://doi.org/10.5194/amt-15-6075-2022, https://doi.org/10.5194/amt-15-6075-2022, 2022
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                                                This study deals with the dynamic error estimates of the aerosol-retrieved properties by the GRASP algorithm, which are provided for directly retrieved and derived parameters. Moreover, GRASP provides full covariance matrices that appear to be a useful approach for optimizing observation schemes and retrieval set-ups. The validation of the retrieved dynamic error estimates is done through real and synthetic measurements using sun photometer and lidar observations.
                                            
                                            
                                        Angelos Karanikolas, Natalia Kouremeti, Julian Gröbner, Luca Egli, and Stelios Kazadzis
                                    Atmos. Meas. Tech., 15, 5667–5680, https://doi.org/10.5194/amt-15-5667-2022, https://doi.org/10.5194/amt-15-5667-2022, 2022
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                                                The aim of this work is to investigate the limitations of calculating long-term trends of a parameter that quantifies the overall effect of atmospheric aerosols on the solar radiation. A main finding is that even instruments with good agreement between their observations can show significantly different linear trends. By calculating time-varying trends, the trend agreement is shown to improve. We also show that different methods of trend estimation can result in significant trend differences.
                                            
                                            
                                        Larisa Sogacheva, Matthieu Denisselle, Pekka Kolmonen, Timo H. Virtanen, Peter North, Claire Henocq, Silvia Scifoni, and Steffen Dransfeld
                                    Atmos. Meas. Tech., 15, 5289–5322, https://doi.org/10.5194/amt-15-5289-2022, https://doi.org/10.5194/amt-15-5289-2022, 2022
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                                                The aim of this study was to provide global characterisation of a new SYNERGY aerosol product derived from the data from the OLCI and SLSTR sensors aboard the Sentinel-3A and Sentinel-3B satellites. Over ocean, the performance of SYNERGY-retrieved AOD is good. Reduced performance over land was expected since the surface reflectance and angular distribution of scattering are more difficult to treat. Validation statistics are often slightly better for S3B and in the Southern Hemisphere.
                                            
                                            
                                        Shikuan Jin, Yingying Ma, Cheng Chen, Oleg Dubovik, Jin Hong, Boming Liu, and Wei Gong
                                    Atmos. Meas. Tech., 15, 4323–4337, https://doi.org/10.5194/amt-15-4323-2022, https://doi.org/10.5194/amt-15-4323-2022, 2022
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                                                Aerosol parameter retrievals have always been a research focus. In this study, we used an advanced aerosol algorithms (GRASP, developed by Oleg Dubovik) to test the ability of DPC/Gaofen-5 (the first polarized multi-angle payload developed in China) images to obtain aerosol parameters. The results show that  DPC/GRASP achieves good results (R > 0.9). This research will contribute to the development of hardware and algorithms for aerosols
                                            
                                            
                                        Zhujun Li, David Painemal, Gregory Schuster, Marian Clayton, Richard Ferrare, Mark Vaughan, Damien Josset, Jayanta Kar, and Charles Trepte
                                    Atmos. Meas. Tech., 15, 2745–2766, https://doi.org/10.5194/amt-15-2745-2022, https://doi.org/10.5194/amt-15-2745-2022, 2022
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                                                For more than 15 years, CALIPSO has revolutionized our understanding of the role of aerosols in climate. Here we evaluate CALIPSO aerosol typing over the ocean using an independent CALIPSO–CloudSat product. The analysis suggests that CALIPSO correctly categorizes clean marine aerosol over the open ocean, elevated smoke over the SE Atlantic, and dust over the tropical Atlantic. Similarities between clean and dusty marine over the open ocean implies that algorithm modifications are warranted.
                                            
                                            
                                        Panagiotis G. Kosmopoulos, Stelios Kazadzis, Alois W. Schmalwieser, Panagiotis I. Raptis, Kyriakoula Papachristopoulou, Ilias Fountoulakis, Akriti Masoom, Alkiviadis F. Bais, Julia Bilbao, Mario Blumthaler, Axel Kreuter, Anna Maria Siani, Kostas Eleftheratos, Chrysanthi Topaloglou, Julian Gröbner, Bjørn Johnsen, Tove M. Svendby, Jose Manuel Vilaplana, Lionel Doppler, Ann R. Webb, Marina Khazova, Hugo De Backer, Anu Heikkilä, Kaisa Lakkala, Janusz Jaroslawski, Charikleia Meleti, Henri Diémoz, Gregor Hülsen, Barbara Klotz, John Rimmer, and Charalampos Kontoes
                                    Atmos. Meas. Tech., 14, 5657–5699, https://doi.org/10.5194/amt-14-5657-2021, https://doi.org/10.5194/amt-14-5657-2021, 2021
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                                                Large-scale retrievals of the ultraviolet index (UVI) in real time by exploiting the modern Earth observation data and techniques are capable of forming operational early warning systems that raise awareness among citizens of the health implications of high UVI doses. In this direction a novel UVI operating system, the so-called UVIOS, was introduced for massive outputs, while its performance was tested against ground-based measurements revealing a dependence on the input quality and resolution.
                                            
                                            
                                        Stefan F. Schreier, Tim Bösch, Andreas Richter, Kezia Lange, Michael Revesz, Philipp Weihs, Mihalis Vrekoussis, and Christoph Lotteraner
                                    Atmos. Meas. Tech., 14, 5299–5318, https://doi.org/10.5194/amt-14-5299-2021, https://doi.org/10.5194/amt-14-5299-2021, 2021
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                                                This paper reports on the evaluation of aerosol profiling products retrieved from ground-based MAX-DOAS instruments using the BOREAS algorithm. Aerosol extinction profiles, near-surface aerosol extinction, and aerosol optical depth are compared to measurements collected with ceilometer, sun photometer, and in situ instruments. We show that these MAX-DOAS aerosol profiling products provide useful information to study spatial and temporal variations above the urban area of Vienna.
                                            
                                            
                                        Carmen Córdoba-Jabonero, Albert Ansmann, Cristofer Jiménez, Holger Baars, María-Ángeles López-Cayuela, and Ronny Engelmann
                                    Atmos. Meas. Tech., 14, 5225–5239, https://doi.org/10.5194/amt-14-5225-2021, https://doi.org/10.5194/amt-14-5225-2021, 2021
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                                                An experimental assessment of a polarized micro-pulse lidar (P-MPL) in comparison to reference lidars is presented regarding the retrieval of aerosol optical properties. The evaluation is focused on both the optimally determined overlap function and volume linear depolarization ratio. A P-MPL overlap must be regularly estimated to derive suitable aerosol products (backscatter, extinction, and particle depolarization ratio). This methodology can be easily applied to other P-MPL systems.
                                            
                                            
                                        Benjamin Torres and David Fuertes
                                    Atmos. Meas. Tech., 14, 4471–4506, https://doi.org/10.5194/amt-14-4471-2021, https://doi.org/10.5194/amt-14-4471-2021, 2021
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                                                The article shows the capacity of the new GRASP-AOD approach to be used for large datasets of aerosol optical depth from ground-based observations, through a comparison with standard AERONET codes. This new approach reduces the requirements in terms of measurements (no need of scattering information) to derive some basic aerosol size and optical properties.  A broad use of this algorithm would increase the datasets of aerosol properties from ground-based observations.
                                            
                                            
                                        Yang Zhang, Zhengqiang Li, Zhihong Liu, Yongqian Wang, Lili Qie, Yisong Xie, Weizhen Hou, and Lu Leng
                                    Atmos. Meas. Tech., 14, 1655–1672, https://doi.org/10.5194/amt-14-1655-2021, https://doi.org/10.5194/amt-14-1655-2021, 2021
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                                                The aerosol fine-mode fraction (FMF) is an important parameter reflecting the content of man-made aerosols. This study carried out the retrieval of FMF in China based on multi-angle polarization data and validated the results. The results of this study can contribute to the FMF retrieval algorithm of multi-angle polarization sensors. At the same time, a high-precision FMF dataset of China was obtained, which can provide basic data for atmospheric environment research.
                                            
                                            
                                        Myrto Gratsea, Tim Bösch, Panagiotis Kokkalis, Andreas Richter, Mihalis Vrekoussis, Stelios Kazadzis, Alexandra Tsekeri, Alexandros Papayannis, Maria Mylonaki, Vassilis Amiridis, Nikos Mihalopoulos, and Evangelos Gerasopoulos
                                    Atmos. Meas. Tech., 14, 749–767, https://doi.org/10.5194/amt-14-749-2021, https://doi.org/10.5194/amt-14-749-2021, 2021
                            Sabrina P. Cochrane, K. Sebastian Schmidt, Hong Chen, Peter Pilewskie, Scott Kittelman, Jens Redemann, Samuel LeBlanc, Kristina Pistone, Meloë Kacenelenbogen, Michal Segal Rozenhaimer, Yohei Shinozuka, Connor Flynn, Amie Dobracki, Paquita Zuidema, Steven Howell, Steffen Freitag, and Sarah Doherty
                                    Atmos. Meas. Tech., 14, 567–593, https://doi.org/10.5194/amt-14-567-2021, https://doi.org/10.5194/amt-14-567-2021, 2021
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                                                Based on observations from the 2016 and 2017 field campaigns of ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS), this work establishes an observationally driven link from mid-visible aerosol optical depth (AOD) and other scene parameters to broadband shortwave irradiance (and by extension the direct aerosol radiative effect, DARE). The majority of the case-to-case DARE variability within the ORACLES dataset is attributable to the dependence on AOD and scene albedo.
                                            
                                            
                                        Omar Torres, Hiren Jethva, Changwoo Ahn, Glen Jaross, and Diego G. Loyola
                                    Atmos. Meas. Tech., 13, 6789–6806, https://doi.org/10.5194/amt-13-6789-2020, https://doi.org/10.5194/amt-13-6789-2020, 2020
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                                                TROPOMI measures the quantity of small suspended particles (aerosols). We describe initial results of aerosol measurements using a NASA algorithm that retrieves the UV aerosol index, aerosol optical depth, and single-scattering albedo. An evaluation of derived products using sun-photometer observations shows close agreement. We also use these results to discuss important biomass burning and wildfire events around the world that got the attention of scientists and news media alike.
                                            
                                            
                                        Priyanka deSouza, Ralph A. Kahn, James A. Limbacher, Eloise A. Marais, Fábio Duarte, and Carlo Ratti
                                    Atmos. Meas. Tech., 13, 5319–5334, https://doi.org/10.5194/amt-13-5319-2020, https://doi.org/10.5194/amt-13-5319-2020, 2020
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                                                This paper presents a novel method to constrain the size distribution derived from low-cost optical particle counters (OPCs) using satellite data to develop higher-quality particulate matter (PM) estimates. Such estimates can enable cities that do not have access to expensive reference air quality monitors, especially those in the global south, to develop effective air quality management plans.
                                            
                                            
                                        Dmitry M. Kabanov, Christoph Ritter, and Sergey M. Sakerin
                                    Atmos. Meas. Tech., 13, 5303–5317, https://doi.org/10.5194/amt-13-5303-2020, https://doi.org/10.5194/amt-13-5303-2020, 2020
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                                                Long-term photometer measurements of two sites on Spitsbergen, Barentsburg and Ny-Ålesund, in the European Arctic are presented and compared. We find slightly higher aerosol optical depths at Barentsburg and attribute this to a higher concentration of small particles.
                                            
                                            
                                        Shi Kuang, Bo Wang, Michael J. Newchurch, Kevin Knupp, Paula Tucker, Edwin W. Eloranta, Joseph P. Garcia, Ilya Razenkov, John T. Sullivan, Timothy A. Berkoff, Guillaume Gronoff, Liqiao Lei, Christoph J. Senff, Andrew O. Langford, Thierry Leblanc, and Vijay Natraj
                                    Atmos. Meas. Tech., 13, 5277–5292, https://doi.org/10.5194/amt-13-5277-2020, https://doi.org/10.5194/amt-13-5277-2020, 2020
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                                                Ozone lidar is a state-of-the-art remote-sensing instrument to measure atmospheric ozone concentrations with high spatiotemporal resolution. In this study, we show that an ozone lidar can also provide reliable aerosol measurements through intercomparison with colocated aerosol lidar observations.
                                            
                                            
                                        Laaziz El Amraoui, Bojan Sič, Andrea Piacentini, Virginie Marécal, Nicolas Frebourg, and Jean-Luc Attié
                                    Atmos. Meas. Tech., 13, 4645–4667, https://doi.org/10.5194/amt-13-4645-2020, https://doi.org/10.5194/amt-13-4645-2020, 2020
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                                                The aim of this paper is to present the assimilation of lidar observations from the CALIOP instrument onboard the CALIPSO satellite in the chemistry-transport model of Météo-France, MOCAGE. We presented the first results of the assimilation of the extinction coefficient observations of the CALIOP lidar instrument during the pre-ChArMEx-TRAQA field campaign. We evaluated the added value of the assimilation product to better document a desert dust transport event compared to the model free run.
                                            
                                            
                                        Carl Malings, Daniel M. Westervelt, Aliaksei Hauryliuk, Albert A. Presto, Andrew Grieshop, Ashley Bittner, Matthias Beekmann, and R. Subramanian
                                    Atmos. Meas. Tech., 13, 3873–3892, https://doi.org/10.5194/amt-13-3873-2020, https://doi.org/10.5194/amt-13-3873-2020, 2020
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                                                Most air quality information comes from accurate but expensive instruments. These can be supplemented by lower-cost sensors to increase the density of ground data and expand monitoring into less well-instrumented areas, like sub-Saharan Africa. In this paper, we look at how low-cost sensor data can be combined with satellite information on air quality (which requires ground data to properly calibrate measurements) and assess the benefits these low-cost sensors provide in this context.
                                            
                                            
                                        Zhong Chen, Pawan K. Bhartia, Omar Torres, Glen Jaross, Robert Loughman, Matthew DeLand, Peter Colarco, Robert Damadeo, and Ghassan Taha
                                    Atmos. Meas. Tech., 13, 3471–3485, https://doi.org/10.5194/amt-13-3471-2020, https://doi.org/10.5194/amt-13-3471-2020, 2020
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                                                The scope of the paper is the evaluation of stratospheric aerosols derived from the OMPS/LP instrument via comparison with independent datasets from the SAGE III/ISS instrument. Results show very good agreement for extinction profiles between an altitude of 19 and 27 km, to within ±25 %, and show systematic differences (LP-SAGE III/ISS) above 28 km and below 19 km (greater than ±25 %).
                                            
                                            
                                        Steven Albers, Stephen M. Saleeby, Sonia Kreidenweis, Qijing Bian, Peng Xian, Zoltan Toth, Ravan Ahmadov, Eric James, and Steven D. Miller
                                    Atmos. Meas. Tech., 13, 3235–3261, https://doi.org/10.5194/amt-13-3235-2020, https://doi.org/10.5194/amt-13-3235-2020, 2020
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                                                A fast 3D visible-light forward operator is used to realistically visualize, validate, and potentially assimilate ground- and space-based camera and satellite imagery with NWP models. Three-dimensional fields of hydrometeors, aerosols, and 2D land surface variables are considered in the generation of radiance fields and RGB imagery from a variety of vantage points.
                                            
                                            
                                        Swadhin Nanda, Martin de Graaf, J. Pepijn Veefkind, Maarten Sneep, Mark ter Linden, Jiyunting Sun, and Pieternel F. Levelt
                                    Atmos. Meas. Tech., 13, 3043–3059, https://doi.org/10.5194/amt-13-3043-2020, https://doi.org/10.5194/amt-13-3043-2020, 2020
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                                                This paper presents a first validation of the TROPOspheric Monitoring Instrument (TROPOMI) aerosol layer height (ALH) product, which is an estimate of the height of an aerosol layer using a spectrometer on board ESA's Sentinel-5 Precursor satellite mission. Comparison between the TROPOMI ALH product and co-located aerosol extinction heights from the CALIOP instrument on board NASA's CALIPSO mission show good agreement for selected cases over the ocean and large differences over land.
                                            
                                            
                                        Debora Griffin, Christopher Sioris, Jack Chen, Nolan Dickson, Andrew Kovachik, Martin de Graaf, Swadhin Nanda, Pepijn Veefkind, Enrico Dammers, Chris A. McLinden, Paul Makar, and Ayodeji Akingunola
                                    Atmos. Meas. Tech., 13, 1427–1445, https://doi.org/10.5194/amt-13-1427-2020, https://doi.org/10.5194/amt-13-1427-2020, 2020
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                                                This study looks into validating the aerosol layer height product from the recently launched TROPOspheric Monitoring Instrument (TROPOMI) for forest fire plume through comparisons with two other satellite products, and interpreting  differences due to the individual measurement techniques.  These satellite observations are compared to predicted plume heights from Environment and Climate Change's air quality forecast model.
                                            
                                            
                                        Jonas Witthuhn, Anja Hünerbein, and Hartwig Deneke
                                    Atmos. Meas. Tech., 13, 1387–1412, https://doi.org/10.5194/amt-13-1387-2020, https://doi.org/10.5194/amt-13-1387-2020, 2020
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                                                Reliable reference measurements over ocean are essential for the evaluation and improvement of satellite- and model-based aerosol datasets. Here, a uniqe set of shipborne reference aerosol products obtained from Microtops sunphotometer and GUVis-3511 shadowband radiometer observations are compared to aerosol products from the MODIS and SEVIRI satellite sensors, and the CAMS reanalysis over the Atlantic Ocean. The present evaluation highlights the importance of an aerosol-type based analysis.
                                            
                                            
                                        Sabine Griessbach, Lars Hoffmann, Reinhold Spang, Peggy Achtert, Marc von Hobe, Nina Mateshvili, Rolf Müller, Martin Riese, Christian Rolf, Patric Seifert, and Jean-Paul Vernier
                                    Atmos. Meas. Tech., 13, 1243–1271, https://doi.org/10.5194/amt-13-1243-2020, https://doi.org/10.5194/amt-13-1243-2020, 2020
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                                                In this paper we study the cloud top height derived from MIPAS measurements. Previous studies showed contradictory results with respect to MIPAS, both underestimating and overestimating cloud top height. We used simulations and found that overestimation and/or underestimation depend on cloud extinction. To support our findings we compared MIPAS cloud top heights of volcanic sulfate aerosol with measurements from CALIOP, ground-based lidar, and ground-based twilight measurements.
                                            
                                            
                                        Ekaterina Y. Zhdanova, Natalia Y. Chubarova, and Alexei I. Lyapustin
                                    Atmos. Meas. Tech., 13, 877–891, https://doi.org/10.5194/amt-13-877-2020, https://doi.org/10.5194/amt-13-877-2020, 2020
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                                                We estimated the distribution of aerosol optical thickness (AOT) with a spatial resolution of 1 km over the Moscow megacity using the MAIAC satellite aerosol product from May to September over the years 2000–2017. We revealed that the MAIAC product is a reliable instrument for assessing the spatial features of urban aerosol pollution and its temporal dynamics. The local aerosol effect is about 0.02–0.04 in AOT in the visible spectral range over the Moscow megacity.
                                            
                                            
                                        Guangliang Fu, Otto Hasekamp, Jeroen Rietjens, Martijn Smit, Antonio Di Noia, Brian Cairns, Andrzej Wasilewski, David Diner, Felix Seidel, Feng Xu, Kirk Knobelspiesse, Meng Gao, Arlindo da Silva, Sharon Burton, Chris Hostetler, John Hair, and Richard Ferrare
                                    Atmos. Meas. Tech., 13, 553–573, https://doi.org/10.5194/amt-13-553-2020, https://doi.org/10.5194/amt-13-553-2020, 2020
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                                                In this paper, we present aerosol retrieval results from the ACEPOL (Aerosol Characterization from Polarimeter and Lidar) campaign, which was a joint initiative between NASA and SRON (the Netherlands Institute for Space Research). We perform aerosol retrievals from different multi-angle polarimeters employed during the ACEPOL campaign and evaluate them against ground-based AERONET measurements and High Spectral Resolution Lidar-2 (HSRL-2) measurements.
                                            
                                            
                                        Andrew M. Sayer, Yves Govaerts, Pekka Kolmonen, Antti Lipponen, Marta Luffarelli, Tero Mielonen, Falguni Patadia, Thomas Popp, Adam C. Povey, Kerstin Stebel, and Marcin L. Witek
                                    Atmos. Meas. Tech., 13, 373–404, https://doi.org/10.5194/amt-13-373-2020, https://doi.org/10.5194/amt-13-373-2020, 2020
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                                                Satellite measurements of the Earth are routinely processed to estimate useful quantities; one example is the amount of atmospheric aerosols (which are particles such as mineral dust, smoke, volcanic ash, or sea spray). As with all measurements and inferred quantities, there is some degree of uncertainty in this process.
There are various methods to estimate these uncertainties. A related question is the following: how reliable are these estimates? This paper presents a method to assess them.
                                            
                                            
                                        Dong Liu, Sijie Chen, Chonghui Cheng, Howard W. Barker, Changzhe Dong, Ju Ke, Shuaibo Wang, and Zhuofan Zheng
                                    Atmos. Meas. Tech., 12, 6541–6556, https://doi.org/10.5194/amt-12-6541-2019, https://doi.org/10.5194/amt-12-6541-2019, 2019
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                                                Aerosols are one of the drivers of climate change, and more information about aerosol vertical distribution is needed to analyze the role of aerosols in the atmosphere. In this work, we match and substitute a pixel along the lidar ground track for every pixel that is not on the track based on the radiance measured by a passive imager, therefore expanding the atmosphere profiles to a nearby region. The accuracy of the construction is confirmed through a procedure mimicking the construction.
                                            
                                            
                                        Hiren Jethva and Omar Torres
                                    Atmos. Meas. Tech., 12, 6489–6503, https://doi.org/10.5194/amt-12-6489-2019, https://doi.org/10.5194/amt-12-6489-2019, 2019
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                                                The intercomparison of satellite- and ground-measured aerosol absorption properties, such as presented here using Aura-OMI and SKYNET sensors, constitutes an important exercise to evaluate relative performance, track algorithm changes, and to diagnose retrieval accuracy and issues. The two datasets are found to agree reasonably well under moderate to higher aerosol loading but show disagreement under lower aerosol amounts due to retrieval issues in both techniques.
                                            
                                            
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