Suchergebnisse

The research leading to these results has received funding from the H2020 program from the European Union (grant agreement no. 654109, 778349) and also from the Spanish Ministry of Industry, Economy and Competitiviness (MINECO, ref. CGL2013-45410-R, CGL2016-81092-R, CGL2017-85344-R, TEC2015-63832-P), the Spanish Ministry of Science, Innovation and Universities (ref. CGL2017-90884-REDT); the CommSensLab "Maria de Maeztu" Unity of Excellence (ref. MDM-2016-0600) financed by the Spanish Agencia Estatal de Investigación. Co-funding was also provided by the European Union through the European Regional Development Fund (ref. POCI-01-0145-FEDER-007690, ALT20-03-0145-FEDER-000004, ALT20-03-0145-FEDER-000011); by the Andalusia Regional Government (ref. P12-RNM-2409); by the Madrid Regional Government (projects TIGAS-CM, ref. Y2018/EMT-5177 and AIRTEC-CM, ref. P2018/EMT4329); by the University of Granada through "Plan Propio. Programa 9 Convocatoria 2013" and by the Portuguese Foundation for Science and Technology and national funding (ref. SFRH/BSAB/143164/2019). The BSC-DREAM8b and NNMB/BSC-Dust (now NMMB-MONARCH) model simulations were performed by the Mare Nostrum supercomputer hosted by the Barcelona Supercomputer Center (BSC). S. Basart acknowledges the AXA Research Fund for supporting aerosol research at the BSC through the AXA Chair on Sand and Dust Storms Fund, as well as the InDust project (COST Action CA16202). The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website (http://www.ready.noaa.gov) used in this publication. ; An unprecedented extreme Saharan dust event was registered in winter time from 20 to 23 February 2017 over the Iberian Peninsula (IP). We report on aerosol optical properties observed under this extreme dust intrusion through passive and active remote sensing techniques. For that, AERONET (AErosol RObotic NETwork) and EARLINET (European Aerosol Research LIdar NETwork) databases are used. The sites considered are: Barcelona (41.38°N, 2.17°E), Burjassot (39.51°N, 0.42°W), Cabo da Roca (38.78°N, 9.50°W), Évora (38.57°N, 7.91°W), Granada (37.16°N, 3.61°W) and Madrid (40.45°N, 3.72°W). Large aerosol optical depths (AOD) and low Ångström exponents (AE) are observed. An AOD of 2.0 at 675 nm is reached in several stations. A maximum peak of 2.5 is registered in Évora. During and around the peak of AOD, AEs close to 0 and even slightly negative are measured. With regard to vertically-resolved aerosol optical properties, particle backscatter coefficients as high as 15 Mm−1 sr−1 at 355 nm are recorded at the lidar stations. Layer-mean lidar ratios are found in the range 40–55 sr at 355 nm and 34–61 sr at 532 nm during the event. The particle depolarization ratios are found to be constant inside the dust layer, and consistent from one site to another. Layer-mean values vary in the range 0.19–0.31. Another remarkable aspect of the event is the limited vertical distribution of the dust plume which never exceeds 5 km. The extreme aspect of the event also presented a nice case for testing the ability of two dust forecast models, BSC-DREAM8b and NMMB/BSC-Dust, to reproduce the arrival, the vertical distribution and the intensity of the dust plume over a long-range transport region. In the particular case of the February 2017 dust event, we found a large underestimation in the forecast of the extinction coefficient provided by BSC-DREAM8b at all heights independently of the site. In contrast NMMB/BSC-Dust forecasts presented a better agreement with the observations, especially in southwestern part of the IP. With regard to the forecast skill as a function of lead time, no clear degradation of the prognostic is appreciated at 24, 48 and 72 h for Évora and Granada stations (South). However the prognostic does degrade (bias increases and/or correlation decreases) for Barcelona (North), which is attributed to the fact that Barcelona is at a greater distance from the source region and to the singularity of the event. ; Funding from the H2020 program from the European Union (grant agreement no. 654109, 778349) ; Spanish Ministry of Industry, Economy and Competitiviness (MINECO, ref. CGL2013-45410-R, CGL2016-81092-R, CGL2017-85344-R, TEC2015-63832-P) ; Spanish Ministry of Science, Innovation and Universities (ref. CGL2017-90884-REDT) ; CommSensLab "Maria de Maeztu" Unity of Excellence (ref. MDM-2016-0600) financed by the Spanish Agencia Estatal de Investigación ; Co-funding was also provided by the European Union through the European Regional Development Fund (ref. POCI-01-0145-FEDER-007690, ALT20-03-0145-FEDER-000004, ALT20-03-0145-FEDER-000011) ; Andalusia Regional Government (ref. P12-RNM-2409); by the Madrid Regional Government (projects TIGAS-CM, ref. Y2018/EMT-5177 and AIRTEC-CM, ref. P2018/EMT4329) ; Portuguese Foundation for Science and Technology and national funding (ref. SFRH/BSAB/143164/2019)

An experimental setup to study aerosol hygroscopicity is proposed based on the temporal evolution of attenuated backscatter coefficients from a ceilometer colocated with an instrumented tower equipped with meteorological sensors at different heights. This setup is used to analyze a 4.5-year database at the ACTRIS SIRTA observatory in Palaiseau (Paris, France, 2.208 E, 48.713 N; 160m above sea level). A strict criterion-based procedure has been established to identify hygroscopic growth cases using ancillary information, such as online chemical composition, resulting in 8 hygroscopic growth cases from a total of 107 potential cases. For these eight cases, hygroscopic growth-related properties, such as the attenuated backscatter enhancement factor fbeta (RH) and the hygroscopic growth coefficient y, are evaluated. This study shows that the hygroscopicity parameter y is negatively correlated with the aerosol organic mass fraction but shows a positive correlation with the aerosol inorganic mass fraction. Among inorganic species, nitrate exhibited the highest correlation. This is the first time that hygroscopic enhancement factors are directly retrieved under ambient aerosols using remotesensing techniques, which are combined with online chemical composition in situ measurements to evaluate the role of the different aerosol species in aerosol hygroscopicity. ; This work was supported by the Andalusia Regional Government through project P12-RNM-2409; the Spanish Ministry of Economy and Competitiveness through projects CGL2013-45410-R, CGL2016-81092-R, and CGL2017-83538-C3- 1-R; the Excellence network CGL2017-90884-REDT; the Juan de la Cierva grant IJCI-2016-29838; and the University of Granada trough the Plan Propio Program P9 Call-2013 contract and project UCE-PP2017. Andrés Esteban Bedoya-Velásquez has been supported by a grant for PhD studies in Colombia, COLCIENCIAS (Doctorado Nacional – 647), associated with the Physics Sciences program at the Universidad Nacional de Colombia, Sede Medellín, and the Asociación Universitaria Iberoamericana de Postgrado (AUIP). Financial support for EARLINET was provided through ACTRIS-2 Research Infrastructure Project EU H2O20 (grant agreement no. 654109), particularly for staying 2 weeks at SIRTA observatory and developing this investigation (TNA 3 SIR AHEAAARS). The authors gratefully acknowledge the FEDER program for the instrumentation used in this work. Juan Antonio Bravo-Aranda has received funding from the Marie Sklodowska-Curie Action Cofund 2016 EU project – Athenea3i under grant agreement no. 754446.

he planetary boundary layer (PBL) is the lowermost region of troposphere and is endowed with turbulent characteristics, which can have mechanical and/or thermodynamic origins. This behavior gives this layer great importance, mainly in studies about pollutant dispersion and weather forecasting. However, the instruments usually applied in studies of turbulence in the PBL have limitations in spatial resolution (anemometer towers) or temporal resolution (instrumentation aboard an aircraft). Ground-based remote sensing, both active and passive, offers an alternative for studying the PBL. In this study we show the capabilities of combining different remote sensing systems (microwave radiometer – MWR, Doppler lidar – DL – and elastic lidar – EL) for retrieving a detailed picture on the PBL turbulent features. The statistical moments of the high frequency distributions of the vertical wind velocity, derived from DL, and of the backscattered coefficient, derived from EL, are corrected by two methodologies, namely first lag correction and -2=3 law correction. The corrected profiles, obtained from DL data, present small differences when compared with the uncorrected profiles, showing the low influence of noise and the viability of the proposed methodology. Concerning EL, in addition to analyzing the influence of noise, we explore the use of different wavelengths that usually include EL systems operated in extended networks, like the European Aerosol Research Lidar Network (EARLINET), ; This work was supported by the Andalusia Regional Government through project P12-RNM-2409 and by the Spanish Agencia Estatal de Investigación (AEI) through projects CGL2016-81092-R and CGL2017-90884-REDT. We acknowledge the financial support by the European Union's Horizon 2020 research and innovation program through project ACTRIS-2 (grant agreement no. 654109).

This work focuses on the analysis of the seasonal cycle of temperature and relative humidity (RH) profiles and integrated water vapor (IWV) obtained from microwave radiometer (MWR) measurements over the mid-latitude city of Granada, southern Spain. For completeness the study, the maximum atmospheric boundary layer height (ABLHmax) is also included. To this end, we have firstly characterized the HATPRO-RPG MWR errors using 55 co-located radiosondes (RS) by means of the mean-bias (biasbar) profile and the standard deviation (SDbias) profile classified under all-weather conditions and cloud-free conditions. This characterization pointed out that temperature from HATPRO-MWR presents a very low biasbar respects RS mostly below 2.0 km agl, ranging from positive to negative values under all-weather conditions (from 1.7 to -0.4 K with SDbias up to 3.0 K). Under cloud-free conditions, the bias was very similar to that found under all-weather conditions (1.8 to -0.4 K) but with smaller SDbias (up to 1.1 K). The same behavior is also seen in this lower part (ground to 2.0 km agl) for RH. Under all-weather conditions, the mean RH bias ranged from 3.0 to -4.0% with SDbias between 10 and 16.3% while under cloud-free conditions the bias ranged from 2.0 to -0.4% with SDbias from 0.5 to 13.3%. Above 2.0 km agl, the SDbias error increases considerably up to 4 km agl (up to -20%), and then decreases slightly above 7.0 km agl (up to -5%). In addition, IWV values from MWR were also compared with the values obtained from the integration of RS profiles, showing a better linear fit under cloud-free conditions (R2 = 0.96) than under all-weather conditions (R2 = 0.82). The mean bias under cloud-free conditions was -0.80 kg/m2 while for all-weather conditions it was -1.25 kg/m2. Thus, the SDbiasfor all the statistics (temperature, RH and IWV) of the comparison between MWR and RS presented higher values for all-weather conditions than for cloud-free conditions ones. It points out that the presence of clouds is a key factor to take into account when MWR products are used. The second part of this work is devoted to a seasonal variability analysis over five years, leading us to characterize thermodynamically the troposphere over our site. This city atmosphere presents a clear seasonal cycle where temperature, ABLHmax and IWV increase from winter to summer and decrease in autumn, meanwhile RH decreases along the warmer seasons. This city presents cold winters (mean daily maximum temperature: 10.6 ± 1.1 °C) and dry/hot summers (mean daily maximum temperature of 28.8 ± 0.9 °C and mean daily maximum of surface RH up to 55.0 ± 6.0%) at surface (680 m asl). Moreover, considering temporal trends, our study pointed out that only temperature and RH showed a linear increase in winters with a mean-rate of (0.5 ± 0.1) °C/year and (3.4 ± 1.7) %/year, respectively, from ground to 2.0 km agl, meanwhile IWV presented a linear increase of 1.0 kg·m-2/year in winters, 0.78 kg·m-2/year in summers and a linear decrease in autumns of -0.75 kg·m-2/year. ; Andalusia Regional Government through project P12-RNM-2409 ; Spanish Ministry of Economy and Competitiveness through projects CGL2013-45410-R, CGL2015-73250-JIN and CGL2016-81092-R ; Juan de la Cierva grant IJCI-2016-30007

Jose Antonio Benavent-Oltra is funded by the University of Granada through "Plan Propio. Programa 7, Convocatoria 2019". Roberto Roman is funded by MINECO under the postdoctoral programme Juan de la Cierva-Incorporacion (IJCI2016-30007). Juan Andres Casquero-Vera is funded by MINECO under the predoctoral programme FPI (BES-2017-080015). Maria J. Granados-Munoz received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 796539. Oleg Dubovik was supported by the Labex CaPPA project, which is funded by the French National Research Agency under contract "ANR-11-LABX0005-01". This work was also supported by the Spanish Ministry of Economy and Competitiveness (projects CMT2015-66742-R, CGL2016-81092-R, CGL2017-85344-R, RTI2018-097864-B-I00 and CGL2017-90884-REDT), by the Andalusia Regional Government through project P18-RT-3820 and the Unity of Excellence "Maria de Maeztu" (project MDM-2016-0600) financed by the Spanish State Research Agency (AEI). The authors thankfully ac-knowledge the FEDER programme for the instrumentation used in this work, the University of Granada, which supported this study through the Excellence Units Program, and the Sierra Nevada National Park. We also thank Dr. Grisa Monick who provided the Aethalometer AVIO AE-33 installed on the aircraft. Thanks to AERONET and ACTRIS/AERONET Europe for the scientific and technical support. Finally, the authors would like to acknowledge the use of the GRASP inversion algorithm software (http://www.grasp-open.com, last access: 1 April 2020), in this work. ; The Sierra Nevada Lidar aerOsol Profiling Experiment I and II (SLOPE I and II) campaigns were intended to determine the vertical structure of aerosols by remote sensing instruments and test the various retrieval schemes for obtaining aerosol microphysical and optical properties with in situ measurements. The SLOPE I and II campaigns were developed during the summers of 2016 and 2017, respectively, combining active and passive remote sensing with in situ measurements at stations belonging to the AGORA observatory (Andalusian Global ObseRvatory of the Atmosphere) in the Granada area (Spain). In this work, we use the in situ measurements of these campaigns to evaluate aerosol properties retrieved by the GRASP code (Generalized Retrieval of Atmosphere and Surface Properties) combining lidar and sun-sky photometer measurements. We show an overview of aerosol properties retrieved by GRASP during the SLOPE I and II campaigns. In addition, we evaluate the GRASP retrievals of total aerosol volume concentration (discerning between fine and coarse modes), extinction and scattering coefficients, and for the first time we present an evaluation of the absorption coefficient. The statistical analysis of aerosol optical and microphysical properties, both column-integrated and vertically resolved, from May to July 2016 and 2017 shows a large variability in aerosol load and types. The results show a strong predominance of desert dust particles due to North African intrusions. The vertically resolved analysis denotes a decay of the atmospheric aerosols with an altitude up to 5 km a.s.l. Finally, desert dust and biomass burning events were chosen to show the high potential of GRASP to retrieve vertical profiles of aerosol properties (e.g. absorption coefficient and single scattering albedo) for different aerosol types. The aerosol properties retrieved by GRASP show good agreement with simultaneous in situ measurements (nephelometer, aethalometer, scanning mobility particle sizer, and aerodynamic particle sizer) performed at the Sierra Nevada Station (SNS) in Granada. In general, GRASP overestimates the in situ data at the SNS with a mean difference lower than 6 mu m(3) cm(-3) for volume concentration, and 11 and 2 Mm(-1)for the scattering and absorption coefficients. On the other hand, the comparison of GRASP with airborne measurements also shows an overestimation with mean absolute differences of 14 +/- 10 and 1.2 +/- 1.2 Mm(-1) for the scattering and absorption coefficients, showing a better agreement for the absorption (scattering) coefficient with higher (lower) aerosol optical depth. The potential of GRASP shown in this study will contribute to enhancing the representativeness of the aerosol vertical distribution and provide information for satellite and global model evaluation. ; University of Granada ; MINECO under the postdoctoral programme Juan de la Cierva-Incorporacion IJCI2016-30007 ; MINECO under the predoctoral programme FPI BES-2017-080015 ; European Commission 796539 ; French National Research Agency (ANR) ANR-11-LABX0005-01 ; Spanish Ministry of Economy and Competitiveness CMT2015-66742-R CGL2016-81092-R CGL2017-85344-R RTI2018-097864-B-I00 CGL2017-90884-REDT ; Andalusia Regional Government P18-RT-3820 ; Spanish State Research Agency (AEI) MDM-2016-0600 ; Excellence Units Program ; Sierra Nevada National Park

The AEAOD– ΔAEAOD grid proposed by Gobbi et al. (2007) is a graphical method used to visually represent the spectral characterization of aerosol optical depth (AOD), i.e. Angström exponent (AE) and its curvature, in order to infer the fine mode contribution (η) to the total AOD and the size of the fine mode aerosol particles. Perrone et al. (2014) applied this method for the wavelengths widely used in lidar measurements. However, in neither case does the method allow for a direct relationship between η and the fine mode fraction contribution to the total aerosol population. Some discussions are made regarding the effect of shape and composition to the classical AE-ΔAE plot. The potential use of particle backscatter measurements, widely used in aerosol characterization methods together with extinction measurements, is also discussed in the AE-ΔAE grid context. A modification is proposed that yields the submicron contribution to the total volume concentration by using particle extinction data, and a comparison to experimental measurements is made. Our results indicate that the use of a modified AE-ΔAE grid plot to directly obtain submicrometric and micrometric mode fraction to the total aerosol population is feasible if a volume-based bimodal particle size distribution is used instead of a number-based one. ; Andalusia Regional Government through project P12-RNM-2409 ; Spanish Ministry of Sciences, Innovation and Universities (CGL2016-81092 and CGL2017 -90884 - REDT)

This study focuses on the analysis of aerosol hygroscopic growth during the Sierra Nevada Lidar AerOsol Profiling Experiment (SLOPE I) campaign by using the synergy of active and passive remote sensors at the ACTRIS Granada station and in situ instrumentation at a mountain station (Sierra Nevada, SNS). To this end, a methodology based on simultaneous measurements of aerosol profiles from an EARLINET multi-wavelength Raman lidar (RL) and relative humidity (RH) profiles obtained from a multi-instrumental approach is used. This approach is based on the combination of calibrated water vapor mixing ratio (r) profiles from RL and continuous temperature profiles from a microwave radiometer (MWR) for obtaining RH profiles with a reasonable vertical and temporal resolution. This methodology is validated against the traditional one that uses RH from co-located radiosounding (RS) measurements, obtaining differences in the hygroscopic growth parameter (γ) lower than 5% between the methodology based on RS and the one presented here. Additionally, during the SLOPE I campaign the remote sensing methodology used for aerosol hygroscopic growth studies has been checked against Mie calculations of aerosol hygroscopic growth using in situ measurements of particle number size distribution and submicron chemical composition measured at SNS. The hygroscopic case observed during SLOPE I showed an increase in the particle backscatter coefficient at 355 and 532nm with relative humidity (RH ranged between 78 and 98%), but also a decrease in the backscatter-related Ångström exponent (AE) and particle linear depolarization ratio (PLDR), indicating that the particles became larger and more spherical due to hygroscopic processes. Vertical and horizontal wind analysis is performed by means of a co-located Doppler lidar system, in order to evaluate the horizontal and vertical dynamics of the air masses. Finally, the Hänel parameterization is applied to experimental data for both stations, and we found good agreement on γ measured with remote sensing (γ532 0.48 ± 0.01 and γ355 0.40 ± 0.01) with respect to the values calculated using Mie theory (γ532 0.53 ± 0.02 and γ355 0.45 ± 0.02), with relative differences between measurements and simulations lower than 9% at 532nm and 11% at 355nm. © Author(s) 2018. ; Acknowledgements. This work was supported by the Andalusia Regional Government through project P12-RNM-2409; by the Spanish Ministry of Economy and Competitiveness through projects CGL2013-45410-R and CGL2016-81092-R, the excelence network CGL2017-90884-REDT, the FPI grant (BES-2014-068893), and the Juan de la Cierva grants FJCI-2014-22052 and FJCI-2014-20819; by the University of Granada trough the Plan Propio Program P9 Call-2013 contract. Andrés Bedoya has been supported by a grant for PhD studies in Colombia, COLCIEN-CIAS (Doctorado Nacional – 647), associated with the Physics Sciences program at the Universidad Nacional de Colombia, Sede Medellín and Asociación Universitaria Iberoamericana de Postgrado (AUIP). The study has also been supported by the Swiss National Science Foundation trough project PZ00P2_168114. Financial support for EARLINET was through the ACTRIS Research Infrastructure Project EU H2020 (Grant agreement no. 654109), particularly trough the TNA GRA-3 HYGROLIRA. We thank the AERO group from ESRL-GMD at NOAA for providing the CPD software used for routine measurements at the SNS, and for their technical support. The authors gratefully acknowledge the FEDER program for the instrumentation used in this work. ; Peer reviewed

This study focuses on the analysis of aerosol hygroscopic growth during the Sierra Nevada Lidar AerOsol Profiling Experiment (SLOPE I) campaign by using the synergy of active and passive remote sensors at the ACTRIS Granada station and in situ instrumentation at a mountain station (Sierra Nevada, SNS). To this end, a methodology based on simultaneous measurements of aerosol profiles from an EARLINET multi-wavelength Raman lidar (RL) and relative humidity (RH) profiles obtained from a multi-instrumental approach is used. This approach is based on the combination of calibrated water vapor mixing ratio (r) profiles from RL and continuous temperature profiles from a microwave radiometer (MWR) for obtaining RH profiles with a reasonable vertical and temporal resolution. This methodology is validated against the traditional one that uses RH from co-located radiosounding (RS) measurements, obtaining differences in the hygroscopic growth parameter (γ) lower than 5 % between the methodology based on RS and the one presented here. Additionally, during the SLOPE I campaign the remote sensing methodology used for aerosol hygroscopic growth studies has been checked against Mie calculations of aerosol hygroscopic growth using in situ measurements of particle number size distribution and submicron chemical composition measured at SNS. The hygroscopic case observed during SLOPE I showed an increase in the particle backscatter coefficient at 355 and 532 nm with relative humidity (RH ranged between 78 and 98 %), but also a decrease in the backscatter-related Ångström exponent (AE) and particle linear depolarization ratio (PLDR), indicating that the particles became larger and more spherical due to hygroscopic processes. Vertical and horizontal wind analysis is performed by means of a co-located Doppler lidar system, in order to evaluate the horizontal and vertical dynamics of the air masses. Finally, the Hänel parameterization is applied to experimental data for both stations, and we found good agreement on γ measured with remote sensing (γ532=0.48±0.01 and γ355=0.40±0.01) with respect to the values calculated using Mie theory (γ532=0.53±0.02 and γ355=0.45±0.02), with relative differences between measurements and simulations lower than 9 % at 532 nm and 11 % at 355 nm. ; This work was supported by the Andalusia Regional Government through project P12-RNM-2409; by the Spanish Ministry of Economy and Competitiveness through projects CGL2013-45410-R and CGL2016-81092-R, the excelence network CGL2017-90884-REDT, the FPI grant (BES-2014- 068893), and the Juan de la Cierva grants FJCI-2014-22052 and FJCI-2014-20819; by the University of Granada trough the Plan Propio Program P9 Call-2013 contract. Andrés Bedoya has been supported by a grant for PhD studies in Colombia, COLCIENCIAS (Doctorado Nacional – 647), associated with the Physics Sciences program at the Universidad Nacional de Colombia, Sede Medellín and Asociación Universitaria Iberoamericana de Postgrado (AUIP). The study has also been supported by the Swiss National Science Foundation trough project PZ00P2_168114. Financial support for EARLINET was through the ACTRIS Research Infrastructure Project EU H2020 (Grant agreement no. 654109), particularly trough the TNA GRA-3 HYGROLIRA. We thank the AERO group from ESRL-GMD at NOAA for providing the CPD software used for routine measurements at the SNS, and for their technical support. The authors gratefully acknowledge the FEDER program for the instrumentation used in this work.

The Sierra Nevada Lidar aerOsol Profiling Experiment I and II (SLOPE I and II) campaigns were intended to determine the vertical structure of aerosols by remote sensing instruments and test the various retrieval schemes for obtaining aerosol microphysical and optical properties with in situ measurements. The SLOPE I and II campaigns were developed during the summers of 2016 and 2017, respectively, combining active and passive remote sensing with in situ measurements at stations belonging to the AGORA observatory (Andalusian Global ObseRvatory of the Atmosphere) in the Granada area (Spain). In this work, we use the in situ measurements of these campaigns to evaluate aerosol properties retrieved by the GRASP code (Generalized Retrieval of Atmosphere and Surface Properties) combining lidar and sun–sky photometer measurements. We show an overview of aerosol properties retrieved by GRASP during the SLOPE I and II campaigns. In addition, we evaluate the GRASP retrievals of total aerosol volume concentration (discerning between fine and coarse modes), extinction and scattering coefficients, and for the first time we present an evaluation of the absorption coefficient. The statistical analysis of aerosol optical and microphysical properties, both column-integrated and vertically resolved, from May to July 2016 and 2017 shows a large variability in aerosol load and types. The results show a strong predominance of desert dust particles due to North African intrusions. The vertically resolved analysis denotes a decay of the atmospheric aerosols with an altitude up to 5 km a.s.l. Finally, desert dust and biomass burning events were chosen to show the high potential of GRASP to retrieve vertical profiles of aerosol properties (e.g. absorption coefficient and single scattering albedo) for different aerosol types. The aerosol properties retrieved by GRASP show good agreement with simultaneous in situ measurements (nephelometer, aethalometer, scanning mobility particle sizer, and aerodynamic particle sizer) performed at the Sierra Nevada Station (SNS) in Granada. In general, GRASP overestimates the in situ data at the SNS with a mean difference lower than 6 µm3 cm−3 for volume concentration, and 11 and 2 Mm−1 for the scattering and absorption coefficients. On the other hand, the comparison of GRASP with airborne measurements also shows an overestimation with mean absolute differences of 14 ± 10 and 1.2 ± 1.2 Mm−1 for the scattering and absorption coefficients, showing a better agreement for the absorption (scattering) coefficient with higher (lower) aerosol optical depth. The potential of GRASP shown in this study will contribute to enhancing the representativeness of the aerosol vertical distribution and provide information for satellite and global model evaluation. ; Jose Antonio Benavent-Oltra is funded by the University of Granada through "Plan Propio. Programa 7, Convocatoria 2019". Roberto Román is funded by MINECO under the postdoctoral programme Juan de la Cierva-Incorporación (IJCI2016-30007). Juan Andrés Casquero-Vera is funded by MINECO under the predoctoral programme FPI (BES-2017-080015). Maria J. Granados-Muñoz received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 796539. Oleg Dubovik was supported by the Labex CaPPA project, which is funded by the French National Research Agency under contract "ANR-11-LABX0005-01". This work was also supported by the Spanish Ministry of Economy and Competitiveness (projects CMT2015-66742-R, CGL2016-81092-R, CGL2017-85344-R, RTI2018-097864-B-I00 and CGL2017-90884-REDT), by the Andalusia Regional Government through project P18-RT-3820 and the Unity of Excellence "María de Maeztu" (project MDM-2016-0600) financed by the Spanish State Research Agency (AEI). The authors thankfully acknowledge the FEDER programme for the instrumentation used in this work, the University of Granada, which supported this study through the Excellence Units Program, and the Sierra Nevada National Park. We also thank Dr. Grisa Monick who provided the Aethalometer AVIO AE-33 installed on the aircraft. Thanks to AERONET and ACTRIS/AERONET Europe for the scientific and technical support. Finally, the authors would like to acknowledge the use of the GRASP inversion algorithm software (http://www.grasp-open.com, last access: 1 April 2020), in this work. ; Peer reviewed

During the 2017 record-breaking burning season in Canada/United States, intense wild fires raged during the first week of September in the Pacific northwestern region (British Columbia, Alberta, Washington, Oregon, Idaho, Montana and northern California) burning mostly temperate coniferous forests. The heavy loads of smoke particles emitted in the atmosphere reached the Iberian Peninsula (IP) a few days later on 7 and 8 September. Satellite imagery allows to identify two main smoke clouds emitted during two different periods that were injected and transported in the atmosphere at several altitude levels. Columnar properties on 7 and 8 September at two Aerosol Robotic Network (AERONET) mid-altitude, background sites in northern and southern Spain are: aerosol optical depth (AOD) at 440 nm up to 0.62, Ångström exponent of 1.6–1.7, large dominance of small particles (fine mode fraction >0.88), low absorption AOD at 440 nm (0.98). Profiles from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) show the presence of smoke particles in the stratosphere during the transport, whereas the smoke is only observed in the troposphere at its arrival over the IP. Portuguese and Spanish ground lidar stations from the European Aerosol Research Lidar Network/Aerosols, Clouds, and Trace gases Research InfraStructure Network (EARLINET/ACTRIS) and the Micro-Pulse Lidar NETwork (MPLNET) reveal smoke plumes with different properties: particle depolarization ratio and color ratio, respectively, of 0.05 and 2.5 in the mid troposphere (5–9 km) and of 0.10 and 3.0 in the upper troposphere (10–13 km). In the mid troposphere the particle depolarization ratio does not seem time-dependent during the transport whereas the color ratio seems to increase (larger particles sediment first). To analyze the horizontal and vertical transport of the smoke from its origin to the IP, particle dispersion modelling is performed with the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) parameterized with satellite-derived biomass burning emission estimates from the Global Fire Assimilation System (GFAS) of the Copernicus Atmosphere Monitoring Service (CAMS). Three compounds are simulated: carbon monoxide, black carbon and organic carbon. The results show that the first smoke plume which travels slowly reaches rapidly (~1 day) the upper troposphere and lower stratosphere (UTLS) but also shows evidence of large scale horizontal dispersion, while the second plume, entrained by strong subtropical jets, reaches the upper troposphere much slower (~2.5 days). Observations and dispersion modelling all together suggest that particle depolarization properties are enhanced during their vertical transport from the mid to the upper troposphere. ; Spanish groups acknowledge the Spanish Ministry of Economy and Competitivity (MINECO) (ref. CGL2013-45410-R, CGL2014-52877-R, CGL2014-55230-R, TEC2015-63832-P, CGL2015-73250-JIN, CGL2016-81092-R and CGL2017-85344-R) ; European Union through H2020 programme ACTRIS-2, grant 654109 ; European Union through H2020 programme EUNADICS-AV, grant 723986 ; European Union through H2020 programme GRASP-ACE, grant 778349