An automatic aerosol classification for earlinet: application and results

Aerosol typing is essential for understanding the impact of the different aerosol sources on climate, weather system and air quality. An aerosol classification method for EARLINET (European Aerosol Research Lidar Network) measurements is introduced which makes use the Mahalanobis distance classifier. The performance of the automatic classification is tested against manually classified EARLINET data. Results of the application of the method to an extensive aerosol dataset will be presented. © The Authors, published by EDP Sciences, 2018.Peer ReviewedPostprint (published version

Lidar-Radiometer Inversion Code (LIRIC) for the retrieval of vertical aerosol properties from combined lidar/radiometer data: Development and distribution in EARLINET

This paper presents a detailed description of LIRIC (LIdar-Radiometer Inversion Code) algorithm for simultaneous processing of coincident lidar and radiometric (sun photometric) observations for the retrieval of the aerosol concentration vertical profiles. As the lidar/radiometric input data we use measurements from European Aerosol Research Lidar Network (EARLINET) lidars and collocated sun-photometers of Aerosol Robotic Network (AERONET). The LIRIC data processing provides sequential inversion of the combined lidar and radiometric data. The algorithm starts with the estimations of column-integrated aerosol parameters from radiometric measurements followed by the retrieval of height dependent concentrations of fine and coarse aerosols from lidar signals using integrated column characteristics of aerosol layer as a priori constraints. The use of polarized lidar observations allows us to discriminate between spherical and non-spherical particles of the coarse aerosol mode. The LIRIC software package was implemented and tested at a number of EARLINET stations. Intercomparison of the LIRIC-based aerosol retrievals was performed for the observations by seven EARLINET lidars in Leipzig, Germany on 25 May 2009. We found close agreement between the aerosol parameters derived from different lidars that supports high robustness of the LIRIC algorithm. The sensitivity of the retrieval results to the possible reduction of the available observation data is also discussed

Workshop on Raising Data using the RDBES and TAF (WKRDBESRaiseTAF; outputs from 2022 meeting)

41 páginasThe Workshop on Raising Data using the RDBES and TAF (WKRDBES-Raise&TAF) met online (26–30 of September 2022) to evaluate the use of the Regional Database and Estimation System (RDBES) format to reproduce the 2022 InterCatch input and output, identifying a Transparent Assessment Framework (TAF) structure to organize the intermediate steps and to propose standardized output formats. The main outcomes of WKRDBES-Raise&TAF were: · RDBES provides sufficient support for current national estimation protocols. However, some minor issues were reported that hampered an exact reproduction of the estimates. Therefore, adaptations of the data model should not be excluded completely. · All the input to stock assessment that InterCatch currently provides, could be reproduced. The participants started from the current stock extracts that can be downloaded from InterCatch. · A workflow was proposed with a national TAF repository for each country, a stock estimation repository and a stock assessment repository. The intermediate output of those repositories will be stored in an ‘intermediate output database’ and depending on the user role, you will get access to the relevant stages in this workflow. · The following requirements for the standard output formats were defined: they cannot be more restrictive than the InterCatch input and output format; they should present measures of uncertainty and sample sizes (for national estimates) and should have a configurable domain definition (for national estimates). Despite those successful outcomes, the current plan for transition to an operational system was concluded to be too optimistic. WKRDBES-Raise&TAF therefore recommends to the Working Group on Governance of the Regional Database and Estimation System (WGRDBESGOV) to revise the roadmap and allow RDBES to be in a test phase also for 2023. WKRDBES-Raise&TAF felt the need to test the proposed workflow on a small scale and therefore recommends to the WGRDBESGOV to arrange a workshop where two stocks (pok.27.3a46 (Saithe (Pollachius virens) in Subareas 4, 6 and Division 3.a (North Sea, Rockall and West of Scotland, Skagerrak and Kattegat) and wit.27.3a47d (Witch (Glyptocephalus cynoglossus) in Subarea 4 and Divisions 3.a and 7.d (North Sea, Skagerrak and Kattegat, eastern English Channel)) will be set up to go through the whole flow.Peer reviewe

Saharan Dust Events Over the Northern Mediterranean: 4 Years of Measurements Over 4 Earlinet Stations

Four years (2014-2017) of observations of depolarization Raman Lidar systems of four EARLINET (European Aerosol research Lidar Network) stations [from West to East: Granada (Spain), Potenza (Italy), Athens (Greece) and Limassol (Cyprus)] were collected and used to a statistical analysis of Saharan dust events over Mediterranean basin. In this study, emphasis is given to the consistency of the particle linear depolarization ratio (δp532), the extinction-to-backscatter ratio mentioned as Lidar Ratio (LR532) and the Aerosol Optical Thickness (AOT532) within the observed Saharan dust layers, corresponding to the visible range (532 nm). Geometrical properties and clusters of aerosol mixtures are also presented. Our clustering was based on previous classification by airborne High Spectral Resolution Lidar (HSRL) observations and was further supported by backward trajectory analysis. We found mean δp532 values of 0.24±0.05, 0.26±0.06, 0.28±0.05 and 0.28±0.04, mean LR532 values of 52±8 sr, 51±9 sr, 52±9 sr and 49±6 sr, mean AOT532 values of 0.40±0.31, 0.11±0.07, 0.12±0.10 and 0.32±0.17 and mean layer thicknesses of 3392±1458 m, 2150±1082 m, 1872±816 m and 1716±567 m for Granada, Potenza, Athens and Limassol respectively. This work could assist in bridging the existing gaps related to the extensive and intensive dust aerosol properties over the Mediterranean and enriching the bibliography about mixed aerosol layers from different sources (e.g. dust and biomass burning (BB) aerosols, dust and urban/ industrial aerosols)

Saharan Dust Events Over the Northern Mediterranean: 4 Years of Measurements Over 4 Earlinet Stations

Four years (2014-2017) of observations of depolarization Raman Lidar systems of four EARLINET (European Aerosol research Lidar Network) stations [from West to East: Granada (Spain), Potenza (Italy), Athens (Greece) and Limassol (Cyprus)] were collected and used to a statistical analysis of Saharan dust events over Mediterranean basin. In this study, emphasis is given to the consistency of the particle linear depolarization ratio (δp532), the extinction-to-backscatter ratio mentioned as Lidar Ratio (LR532) and the Aerosol Optical Thickness (AOT532) within the observed Saharan dust layers, corresponding to the visible range (532 nm). Geometrical properties and clusters of aerosol mixtures are also presented. Our clustering was based on previous classification by airborne High Spectral Resolution Lidar (HSRL) observations and was further supported by backward trajectory analysis. We found mean δp532 values of 0.24±0.05, 0.26±0.06, 0.28±0.05 and 0.28±0.04, mean LR532 values of 52±8 sr, 51±9 sr, 52±9 sr and 49±6 sr, mean AOT532 values of 0.40±0.31, 0.11±0.07, 0.12±0.10 and 0.32±0.17 and mean layer thicknesses of 3392±1458 m, 2150±1082 m, 1872±816 m and 1716±567 m for Granada, Potenza, Athens and Limassol respectively. This work could assist in bridging the existing gaps related to the extensive and intensive dust aerosol properties over the Mediterranean and enriching the bibliography about mixed aerosol layers from different sources (e.g. dust and biomass burning (BB) aerosols, dust and urban/ industrial aerosols)

ATHLI16: the ATHens Lidar Intercomparison campaign

The results of the ATHLI16 (ATHens Lidar Intercomparison) campaign, held in Athens from 26/09 to 07/10 2016 are presented. The campaign was performed within the Lidar Calibration Centre activities (EU H2020 ACTRIS-2 project) to assess the performance of the EOLE lidar system (NTUA, Athens, Greece), operating within EARLINET, by comparing against the EARLINET reference lidar system MUSA (CNR-IMAA, Potenza, Italy). For both lidars only products retrieved by the EARLINET Single Calculus Chain have been compared

ATHLI16: the ATHens Lidar Intercomparison campaign

The results of the ATHLI16 (ATHens Lidar Intercomparison) campaign, held in Athens from 26/09 to 07/10 2016 are presented. The campaign was performed within the Lidar Calibration Centre activities (EU H2020 ACTRIS-2 project) to assess the performance of the EOLE lidar system (NTUA, Athens, Greece), operating within EARLINET, by comparing against the EARLINET reference lidar system MUSA (CNR-IMAA, Potenza, Italy). For both lidars only products retrieved by the EARLINET Single Calculus Chain have been compared

Workshop on Data-limited Stocks of Short-Lived Species (WKDLSSLS2). ICES Scientific Reports

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