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Vassilis Amiridis
Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, Athens, Greece

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Preprint content
Published: 19 July 2021
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Quantifying the dust optical depth (DOD) and its uncertainty across spatiotemporal scales is key to understanding and constraining the dust cycle and its interactions with the Earth System. This study quantifies the DOD along with its monthly and year-to-year variability between 2003 and 2017 at global and regional levels based on the MIDAS (ModIs Dust AeroSol) dataset, which combines MODIS-Aqua retrievals and MERRA-2 reanalysis products. We also describe the annual and seasonal geographical distributions of DOD across the main dust source regions and transport pathways. MIDAS provides columnar mid-visible (550 nm) DOD at fine spatial resolution (0.1° × 0.1°), expanding the current observational capabilities for monitoring the highly variable spatiotemporal features of the dust burden. We obtain a global DOD of 0.032 ± 0.003 – approximately a quarter (23.4 % ± 2.4 %) of the global AOD – with about one order of magnitude more DOD in the northern hemisphere (0.056 ± 0.004; 31.8 % ± 2.7 %) than in the southern hemisphere (0.008 ± 0.001; 8.2 % ± 1.1 %) and about 3.5 times more DOD over land (0.070 ± 0.005) than over ocean (0.019 ± 0.002). The northern hemisphere monthly DOD is highly correlated with the corresponding monthly AOD (R2 = 0.94) and contributes 20 % to 48 % of it, both indicating a dominant dust contribution. In contrast, the contribution of dust to the monthly AOD does not exceed 17 % in the southern hemisphere, although the uncertainty in this region is larger. Among the major dust sources of the planet, the maximum DODs (~1.2) are recorded in the Bodélé Depression of the northern Lake Chad Basin, whereas moderate-to-high intensities are encountered in the Western Sahara (boreal summer), along the eastern parts of the Middle East (boreal summer) and in the Taklamakan Desert (spring). Over oceans, major long-range dust transport is observed primarily along the Tropical Atlantic (intensified during boreal summer) and secondarily in the North Pacific (intensified during boreal spring). Our calculated global and regional averages and associated uncertainties are consistent with some but not all recent observationally based studies. Our work provides a simple, yet flexible method to estimate consistent uncertainties across spatiotemporal scales, which will enhance the use of the MIDAS dataset in future studies.

ACS Style

Antonis Gkikas; Emmanouil Proestakis; Vassilis Amiridis; Stelios Kazadzis; Enza Di Tomaso; Eleni Marinou; Nikos Hatzianastassiou; Jasper F. Kok; Carlos Pérez García-Pando. Quantification of the dust optical depth across spatiotemporal scales with the MIDAS global dataset (2003–2017). 2021, 2021, 1 -51.

AMA Style

Antonis Gkikas, Emmanouil Proestakis, Vassilis Amiridis, Stelios Kazadzis, Enza Di Tomaso, Eleni Marinou, Nikos Hatzianastassiou, Jasper F. Kok, Carlos Pérez García-Pando. Quantification of the dust optical depth across spatiotemporal scales with the MIDAS global dataset (2003–2017). . 2021; 2021 ():1-51.

Chicago/Turabian Style

Antonis Gkikas; Emmanouil Proestakis; Vassilis Amiridis; Stelios Kazadzis; Enza Di Tomaso; Eleni Marinou; Nikos Hatzianastassiou; Jasper F. Kok; Carlos Pérez García-Pando. 2021. "Quantification of the dust optical depth across spatiotemporal scales with the MIDAS global dataset (2003–2017)." 2021, no. : 1-51.

Preprint content
Published: 28 June 2021
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Stavros-Andreas Logothetis; Vasileios Salamalikis; Antonis Gkikas; Stelios Kazadzis; Vassilis Amiridis; Andreas Kazantzidis. Supplementary material to "15-year variability of desert dust optical depth on global and regional scales". 2021, 1 .

AMA Style

Stavros-Andreas Logothetis, Vasileios Salamalikis, Antonis Gkikas, Stelios Kazadzis, Vassilis Amiridis, Andreas Kazantzidis. Supplementary material to "15-year variability of desert dust optical depth on global and regional scales". . 2021; ():1.

Chicago/Turabian Style

Stavros-Andreas Logothetis; Vasileios Salamalikis; Antonis Gkikas; Stelios Kazadzis; Vassilis Amiridis; Andreas Kazantzidis. 2021. "Supplementary material to "15-year variability of desert dust optical depth on global and regional scales"." , no. : 1.

Preprint content
Published: 28 June 2021
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This study aims to investigate the global, regional and seasonal temporal dust changes as well as the effect of dust particles on total aerosol loading, using the MIDAS fine resolution dataset. MIDAS delivers dust optical depth (DOD) at fine spatial resolution (0.1° × 0.1°) spanning from 2003 to 2017. Within this study period, the dust burden has been increased across Central Sahara (up to 0.023 yr−1) and Arabian Peninsula (up to 0.024 yr−1). Both regions observed their highest seasonal trends in summer (up to 0.031 yr−1). On the other side, declining DOD trends are encountered in Western (down to −0.015 yr−1) and Eastern (down to −0.023 yr−1) Sahara, Bodélé Depression (down to −0.021 yr−1), Thar (down to −0.017 yr−1) and Gobi (down to −0.011 yr−1) Deserts and Mediterranean Basin (down to −0.009 yr−1). At spring, the most negative seasonal trends are recorded in Bodélé Depression (down to −0.038 yr−1) and Gobi Desert (down to −0.023 yr−1) whereas in West (down to −0.028 yr−1) and East Sahara (down to −0.020 yr−1), and Thar Desert (down to −0.047 yr−1) at summer. Over western and eastern sector of Mediterranean Basin, the most negative seasonal trends are computed at summer (down to −0.010 yr−1) and spring (down to −0.006 yr−1), respectively. The effect of DOD to the total aerosol optical depth (AOD) changes is determined calculating the DOD to AOD ratio. Over Sahara Desert the median ratio values range from 0.83 to 0.95 whereas in other dust affected areas (Arabian Peninsula, South Mediterranean, Thar and Gobi Deserts) is recorded approximately around 0.6. In addition, a comprehensive analysis of the factors effecting the sign, the magnitude and the statistical significance of the calculated trends is conducted. Firstly, the implications between the implementation of geometric mean instead of arithmetic mean to trend calculations are discussed revealing that the arithmetic-based trends tend to overestimate compared with the geometric-based trends both over land and ocean. Secondly, an analysis interpreting the differences in trend calculations under different spatial resolutions (fine and coarse) and time intervals is conducted, which sounds a critical aspect when satellite-based measurements are utilized.

ACS Style

Stavros-Andreas Logothetis; Vasileios Salamalikis; Antonis Gkikas; Stelios Kazadzis; Vassilis Amiridis; Andreas Kazantzidis. 15-year variability of desert dust optical depth on global and regional scales. 2021, 2021, 1 -40.

AMA Style

Stavros-Andreas Logothetis, Vasileios Salamalikis, Antonis Gkikas, Stelios Kazadzis, Vassilis Amiridis, Andreas Kazantzidis. 15-year variability of desert dust optical depth on global and regional scales. . 2021; 2021 ():1-40.

Chicago/Turabian Style

Stavros-Andreas Logothetis; Vasileios Salamalikis; Antonis Gkikas; Stelios Kazadzis; Vassilis Amiridis; Andreas Kazantzidis. 2021. "15-year variability of desert dust optical depth on global and regional scales." 2021, no. : 1-40.

Preprint content
Published: 09 June 2021
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Atmospheric mineral dust has a rich tri-dimensional spatial and temporal structure that is poorly constrained in forecasts and analyses when only column-integrated aerosol optical depth (AOD) is assimilated. At present, this is the case of most operational global aerosol assimilation products. Aerosol vertical distributions obtained from space-borne lidars can be assimilated in aerosol models, but questions about the extent of their benefit upon analyses and forecasts along with their consistency with AOD assimilation remain unresolved. Our study thoroughly explores the added value of assimilating space-borne vertical dust profiles, with and without the joint assimilation of dust optical depth (DOD). We also discuss the consistency in the assimilation of both sources of information and analyse the role of the smaller footprint of the space-borne lidar profiles upon the results. To that end, we have performed data assimilation experiments using dedicated dust observations for a period of two months over Northern Africa, the Middle East and Europe. We assimilate DOD derived from VIIRS/SUOMI-NPP Deep Blue, and for the first time CALIOP-based LIVAS pure-dust extinction coefficient profiles on an aerosol model. The evaluation is performed against independent ground-based DOD derived from AERONET Sun photometers and ground-based lidar dust extinction profiles from field campaigns (CyCARE and Pre-TECT). Jointly assimilating LIVAS and Deep Blue data reduces the root mean square error (RMSE) in the DOD by 39 % and in the dust extinction coefficient by 65 % compared to a control simulation that excludes assimilation. We show that the assimilation of dust extinction coefficient profiles provides a strong added value to the analyses and forecasts. When only Deep Blue data are assimilated the RMSE in the DOD is reduced further, by 42 %. However, when only LIVAS data are assimilated the RMSE in the dust extinction coefficient decreases by 72 %, the largest improvement across experiments. We also show that the assimilation of dust extinction profiles yields better skill scores than the assimilation of DOD under equivalent sensor footprint. Our results demonstrate the strong potential of future lidar space missions to improve desert dust forecasts, particularly if they foresee a depolarization lidar channel to allow discriminating desert dust from other aerosol types.

ACS Style

Jerónimo Escribano; Enza Di Tomaso; Oriol Jorba; Martina Klose; Maria Gonçalves Ageitos; Francesca Macchia; Vassilis Amiridis; Holger Baars; Eleni Marinou; Emmanouil Proestakis; Claudia Urbanneck; Dietrich Althausen; Johannes Bühl; Rodanthi-Elisavet Mamouri; Carlos Pérez García-Pando. Assimilating spaceborne lidar dust extinction improves dust forecasts. 2021, 2021, 1 -36.

AMA Style

Jerónimo Escribano, Enza Di Tomaso, Oriol Jorba, Martina Klose, Maria Gonçalves Ageitos, Francesca Macchia, Vassilis Amiridis, Holger Baars, Eleni Marinou, Emmanouil Proestakis, Claudia Urbanneck, Dietrich Althausen, Johannes Bühl, Rodanthi-Elisavet Mamouri, Carlos Pérez García-Pando. Assimilating spaceborne lidar dust extinction improves dust forecasts. . 2021; 2021 ():1-36.

Chicago/Turabian Style

Jerónimo Escribano; Enza Di Tomaso; Oriol Jorba; Martina Klose; Maria Gonçalves Ageitos; Francesca Macchia; Vassilis Amiridis; Holger Baars; Eleni Marinou; Emmanouil Proestakis; Claudia Urbanneck; Dietrich Althausen; Johannes Bühl; Rodanthi-Elisavet Mamouri; Carlos Pérez García-Pando. 2021. "Assimilating spaceborne lidar dust extinction improves dust forecasts." 2021, no. : 1-36.

Measurement report
Published: 05 May 2021 in Atmospheric Chemistry and Physics
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This paper presents measurements of mineral dust concentration in the diameter range from 0.4 to 14.0 µm with a novel balloon-borne optical particle counter, the Universal Cloud and Aerosol Sounding System (UCASS). The balloon launches were coordinated with ground-based active and passive remote-sensing observations and airborne in situ measurements with a research aircraft during a Saharan dust outbreak over Cyprus from 20 to 23 April 2017. The aerosol optical depth at 500 nm reached values up to 0.5 during that event over Cyprus, and particle number concentrations were as high as 50 cm−3 for the diameter range between 0.8 and 13.9 µm. Comparisons of the total particle number concentration and the particle size distribution from two cases of balloon-borne measurements with aircraft observations show reasonable agreement in magnitude and shape despite slight mismatches in time and space. While column-integrated size distributions from balloon-borne measurements and ground-based remote sensing show similar coarse-mode peak concentrations and diameters, they illustrate the ambiguity related to the missing vertical information in passive sun photometer observations. Extinction coefficient inferred from the balloon-borne measurements agrees with those derived from coinciding Raman lidar observations at height levels with particle number concentrations smaller than 10 cm−3 for the diameter range from 0.8 to 13.9 µm. An overestimation of the UCASS-derived extinction coefficient of a factor of 2 compared to the lidar measurement was found for layers with particle number concentrations that exceed 25 cm−3, i.e. in the centre of the dust plume where particle concentrations were highest. This is likely the result of a variation in the refractive index and the shape and size dependency of the extinction efficiency of dust particles along the UCASS measurements. In the future, profile measurements of the particle number concentration and particle size distribution with the UCASS could provide a valuable addition to the measurement capabilities generally used in field experiments that are focussed on the observation of coarse aerosols and clouds.

ACS Style

Maria Kezoudi; Matthias Tesche; Helen Smith; Alexandra Tsekeri; Holger Baars; Maximilian Dollner; Víctor Estellés; Johannes Bühl; Bernadett Weinzierl; Zbigniew Ulanowski; Detlef Müller; Vassilis Amiridis. Measurement report: Balloon-borne in situ profiling of Saharan dust over Cyprus with the UCASS optical particle counter. Atmospheric Chemistry and Physics 2021, 21, 6781 -6797.

AMA Style

Maria Kezoudi, Matthias Tesche, Helen Smith, Alexandra Tsekeri, Holger Baars, Maximilian Dollner, Víctor Estellés, Johannes Bühl, Bernadett Weinzierl, Zbigniew Ulanowski, Detlef Müller, Vassilis Amiridis. Measurement report: Balloon-borne in situ profiling of Saharan dust over Cyprus with the UCASS optical particle counter. Atmospheric Chemistry and Physics. 2021; 21 (9):6781-6797.

Chicago/Turabian Style

Maria Kezoudi; Matthias Tesche; Helen Smith; Alexandra Tsekeri; Holger Baars; Maximilian Dollner; Víctor Estellés; Johannes Bühl; Bernadett Weinzierl; Zbigniew Ulanowski; Detlef Müller; Vassilis Amiridis. 2021. "Measurement report: Balloon-borne in situ profiling of Saharan dust over Cyprus with the UCASS optical particle counter." Atmospheric Chemistry and Physics 21, no. 9: 6781-6797.

Preprint content
Published: 04 March 2021
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The Tropics are covering around 40% of the globe and are home to approximately 40% of the world population. However, numerical weather prediction (NWP) for this region still remains challenging due to the lack of basic observations and incomplete understanding of atmospheric processes, also affecting extratropical storm developments. As a result, the largest impact of the ESA’s Aeolus satellite observations on NWP is expected in the Tropics where only a very limited number of wind profile observations from the ground can be performed.

An especially important case relating to the predictability of tropical weather system is the outflow of Saharan dust, its interaction with cloud micro-physics and the overall impact on the development of tropical storms over the Atlantic Ocean. The region of the coast of West Africa uniquely allows the study of the Saharan Aerosol layer, African Easterly Waves and Jets, Tropical Easterly Jet, as well as the deep convection in ITCZ and their relation to the formation of convective systems and the transport of dust.

Together with international partners, ESA and NASA are currently implementing a joint Tropical campaign from July to August 2021 with its base in Cape Verde. The campaign objective is to provide information on the validation and preparation of the ESA missions Aeolus and EarthCARE, respectively, as well as supporting a range of related science objectives for the investigation in the interactions between African Easterly and other tropical waves with the mean flow, dust and their impact on the development of convective systems; the structure and variability of the marine boundary layer in relation to initiation and lifecycle of the convective cloud systems within and across the ITCZ; and impact of wind, aerosol, clouds, and precipitation effects on long range dust transport and air quality over the western Atlantic.

The campaign comprises a unique combination of both strong airborne and ground-based elements collocated on Cape Verde. The airborne component with wind and aerosol lidars, cloud radars, in-situ instrumentation and additional observations includes the NASA DC-8 with science activities coordinated by the U. of Washington, the German DLR Falcon-20, the French Safire Falcon-20 with activities led by LATMOS, and the Slovenian Aerovizija Advantic WT-10 light aircraft in cooperation with the U. Novo Gorica. The ground-based component led by the National Observatory of Athens is a collaboration of more than 25 European teams providing in-situ and remote sensing aerosol and cloud measurements with a wide range of lidar, radar and radiometer systems, as well as drone observatins by the Cyprus Institute.

In preparation for the field campaign, the NASA and ESA management and science teams are closely collaborating with regular coordination meetings, in particular in coordinating the shift of the activity by one year due to the COVID-19 pandemic. The time gained has been used to further consolidate the planning, and in particular with a dry-run campaign organized by NASA with European participation where six virtual flights were conducted in July 2020.

 This paper will present a summary of the campaign preparation activities and the consolidated plan for the 2021 Tropical campaign.

ACS Style

Thorsten Fehr; Gail Skofronick-Jackson; Vassilis Amiridis; Jonas von Bismarck; Shuyi Chen; Cyrille Flamant; Rob Koopman; Christian Lemmerz; Griša Močnik; Tommaso Parrinello; Aaron Piña; Anne Grete Straume. The Joint ESA-NASA Tropical Campaign Activity – Aeolus Calibration/Validation and Science in the Topics. 2021, 1 .

AMA Style

Thorsten Fehr, Gail Skofronick-Jackson, Vassilis Amiridis, Jonas von Bismarck, Shuyi Chen, Cyrille Flamant, Rob Koopman, Christian Lemmerz, Griša Močnik, Tommaso Parrinello, Aaron Piña, Anne Grete Straume. The Joint ESA-NASA Tropical Campaign Activity – Aeolus Calibration/Validation and Science in the Topics. . 2021; ():1.

Chicago/Turabian Style

Thorsten Fehr; Gail Skofronick-Jackson; Vassilis Amiridis; Jonas von Bismarck; Shuyi Chen; Cyrille Flamant; Rob Koopman; Christian Lemmerz; Griša Močnik; Tommaso Parrinello; Aaron Piña; Anne Grete Straume. 2021. "The Joint ESA-NASA Tropical Campaign Activity – Aeolus Calibration/Validation and Science in the Topics." , no. : 1.

Preprint content
Published: 04 March 2021
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Volcanic eruptions are a natural disaster with significant impact on human activities. The unprecedented European Volcanic Ash Crisis in 2010 demonstrated the vulnerability of the infrastructure and the need for new approaches to enable stakeholders in the aviation sector to obtain fast and accurate information. Currently, there are many data sources available and cutting-edge technology to provide the means to detect and monitor high impact eruptions. However, the information from multiple data sources is not yet efficiently integrated and aviation-specific products incorporating multi-platform datasets is not in place. To this end, the integration of tailored ground-based, satellite, and model data as well as information from volcanic observatories in Europe is essential. The Pilot EO4D_ash – Earth observation data for detection, discrimination & distribution (4D) of volcanic ash – of the e-shape project aims to strengthen the Earth Observation and in-situ data exploitation and multi-source (satellite, remotely sensed, and ground-based network) data integration  to derive innovation for ash discrimination and monitoring; to enhance the capability of 4D forecasting volcanic ash dispersal and to foster innovation in the decision making processes and mitigate ash related impact and hazard resilience. The overall pilot structure, tailored products, aerosol lidar profile assimilation and study cases will be presented at the conference.

Acknowledgements: This work has been conducted within the framework of the H2020 e-shape (Grant Agreement n. 820852) project.

ACS Style

Nikolaos Papagiannopoulos; Lucia Mona; Claudio Dema; Vassilis Amiridis; Anna Gialitaki; Anna Kampouri; Andreas Uppstu; Simona Scollo; Luca Merucci; Marie Boichu; Philippe Goloub; Sara Barsotti; Michelle Parks. EO4D_ash – Earth observation data for detection, discrimination & distribution (4D) of volcanic ash. 2021, 1 .

AMA Style

Nikolaos Papagiannopoulos, Lucia Mona, Claudio Dema, Vassilis Amiridis, Anna Gialitaki, Anna Kampouri, Andreas Uppstu, Simona Scollo, Luca Merucci, Marie Boichu, Philippe Goloub, Sara Barsotti, Michelle Parks. EO4D_ash – Earth observation data for detection, discrimination & distribution (4D) of volcanic ash. . 2021; ():1.

Chicago/Turabian Style

Nikolaos Papagiannopoulos; Lucia Mona; Claudio Dema; Vassilis Amiridis; Anna Gialitaki; Anna Kampouri; Andreas Uppstu; Simona Scollo; Luca Merucci; Marie Boichu; Philippe Goloub; Sara Barsotti; Michelle Parks. 2021. "EO4D_ash – Earth observation data for detection, discrimination & distribution (4D) of volcanic ash." , no. : 1.

Preprint content
Published: 04 March 2021
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In December 2019, a contract between CNR and ECMWF was signed for a pilot ACTRIS/EARLINET data provision to the Copernicus Atmosphere Monitoring Service (CAMS). Such pilot contract (CAMS21b) aims to put in place a first data provision for a set of selected stations and it will demonstrate the feasibility of fully traceable and quality-controlled data provision for the whole network.

In CAMS21b, the main effort is devoted to design, test and set up the provision of quality-controlled ACTRIS/EARLINET products in Real Real Time (RRT) and/or Near Real Time (NRT) to CAMS. The activities are focused on the automatic centralized data processing and data provision, ensuring the full traceability of the products from the data acquisition level up to the final quality-controlled data level. Most of the activities are done at ARES, the EARLINET/ACTRIS data center node at CNR, for assuring the centralized, harmonized and quality-controlled processing in compliance with FAIR principles.

New modules and submodules of the ACTRIS/EARLINET Single Calculus Chain (SCC) as well as optimized algorithms for cloud screening have been designed. Additional procedures were implemented for improving the quality of the data provided in NRT, but also for the quality control of the Level 2 products which are delivered with a time delay.

The release of a new version of SCC and of QC procedure is planned for mid-February.

The data provision started in October 2020 at the test site of Potenza. A system has been set up for measurement reporting and monitoring of KPIs (Key Performance Indicators). After 3 months of measurements, the overall data provision system showed no critical points.

In January 2021, the provision started for a group of 9 stations which are seen as representative for the whole network in terms of instrumental capability, but also ensuring a good geographical coverage of the European continent.

In order to accommodate also measurements from non-continuous operation systems, a measurement schedule has been set up, compromising between the need of a large number of measurements and costs/efforts at each station. The measurement schedule has been designed through a representativeness study and foresees 6 slots of measurements per week, 3 in daytime and 3 in nighttime conditions.

The successful implementation of the pilot allows the provision of aerosol optical property profiles to the CAMS services. from a set of observational sites distributed over the different European regions. These profiles is expected to be of interest for the assimilation, near real time evaluation and re-analysis evaluation of several CAMS products, including the aerosol load over Europe for air quality issues, atmospheric composition, climate forcing and solar and UV products. This allows for having a systematic solution for looking into specific events as they develop (e.g. the dust plume that you investigated earlier this month or the Californian fires in September), supporting or contradicting model forecasts. This pilot is the first provision of aerosol profiles from a high-quality ground-based network in NRT for this kind of applications. It is expected that these efforts will be continued in the next phase of CAMS/Copernicus (2021-2027).

ACS Style

Lucia Mona; Giuseppe D'Amico; Simone Gagliardi; Francesco Amato; Aldo Amodeo; Sergio Ciamprone; Benedetto De Rosa; Ermann Ripepi; Donato Summa; Lucas Alados-Arboledas; Vassilis Amiridis; Holger Baars; Mika Kompula; Ina Mattis; Doina Nicolae; Christoper Pietras; Iwona S. Stachlewska; Vincent Henri Peuch. Pilot provision of EARLINET/ACTRIS lidar profiles to CAMS. 2021, 1 .

AMA Style

Lucia Mona, Giuseppe D'Amico, Simone Gagliardi, Francesco Amato, Aldo Amodeo, Sergio Ciamprone, Benedetto De Rosa, Ermann Ripepi, Donato Summa, Lucas Alados-Arboledas, Vassilis Amiridis, Holger Baars, Mika Kompula, Ina Mattis, Doina Nicolae, Christoper Pietras, Iwona S. Stachlewska, Vincent Henri Peuch. Pilot provision of EARLINET/ACTRIS lidar profiles to CAMS. . 2021; ():1.

Chicago/Turabian Style

Lucia Mona; Giuseppe D'Amico; Simone Gagliardi; Francesco Amato; Aldo Amodeo; Sergio Ciamprone; Benedetto De Rosa; Ermann Ripepi; Donato Summa; Lucas Alados-Arboledas; Vassilis Amiridis; Holger Baars; Mika Kompula; Ina Mattis; Doina Nicolae; Christoper Pietras; Iwona S. Stachlewska; Vincent Henri Peuch. 2021. "Pilot provision of EARLINET/ACTRIS lidar profiles to CAMS." , no. : 1.

Preprint content
Published: 04 March 2021
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Mineral dust is an important component of the climate system, affecting radiation, cloud formation, biogeochemical cycles, as well as having negative effects on solar energy budget and human health. All these processes are affected from the size of the particles which is significantly underestimated by the Earth System Models. Here, we present results from a first attempt to modify the size distribution parameterizations in the GOCART-AFWA dust scheme of WRF - Chem, by including the large dust particles with diameters greater than 20 µm to describe the mineral dust cycle. The parameterization is based on Saharan dust observational datasets from FENNEC and SAMUM campaigns. We investigate the impact of the extended size distribution on the overall transported dust load and also the impact of particle settling considerations in deposition rates. The model results are compared with airborne dust measurements from AER-D campaign. In order to achieve the best agreement with the observations, an artificial force that counteracts gravity approximately by 80% for the large particles is needed, indicating the presence of one or more under-represented physical processes in the model.

Acknowledgment: This research was supported by D-TECT (Grant Agreement 725698) funded by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme. 

ACS Style

Eleni Drakaki; Alexandra Tsekeri; Vasillis Amiridis; Stavros Solomos; Antonis Gkikas; Emmanouil Proestakis; Christos Spyrou; Sotirios Mallios; Eleni Marinou; Claire L. Ryder; Petros Katsafados. A modeling insight into the transport of large dust particles. 2021, 1 .

AMA Style

Eleni Drakaki, Alexandra Tsekeri, Vasillis Amiridis, Stavros Solomos, Antonis Gkikas, Emmanouil Proestakis, Christos Spyrou, Sotirios Mallios, Eleni Marinou, Claire L. Ryder, Petros Katsafados. A modeling insight into the transport of large dust particles. . 2021; ():1.

Chicago/Turabian Style

Eleni Drakaki; Alexandra Tsekeri; Vasillis Amiridis; Stavros Solomos; Antonis Gkikas; Emmanouil Proestakis; Christos Spyrou; Sotirios Mallios; Eleni Marinou; Claire L. Ryder; Petros Katsafados. 2021. "A modeling insight into the transport of large dust particles." , no. : 1.

Preprint content
Published: 04 March 2021
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The EVE (Enhancement and Validation of ESA products) lidar is a mobile, ground-based, polarization lidar system, developed to provide ground reference measurements for the validation of the Aeolus L2A products. The system utilizes a dual-laser/dual-telescope configuration that emits linearly and circularly polarized light at 355 nm  interleaved and detects the linear and circular depolarization on the backscattered signals as well as the Raman backscattering at 387 nm. Consequently, the particle optical properties of backscatter coefficient, extinction coefficient, linear and circular depolarization ratios can be measured by the lidar. Moreover, the system’s dual configuration enables to mimic both the operation of ALADIN on board Aeolus that relies on the circularly polarized emission and the operation of a polarization lidar system with linearly polarized emission. Besides EVE’s main goal of the Aeolus L2A products performance evaluation under a wide variety of aerosol types, EVE can also validate the linear to circular depolarization conversions, which have to be used for the harmonization of the linearly polarized lidar systems with Aeolus, and as such, to evaluate any possible biases of the efforts of these systems on Aeolus L2A validation.

ACS Style

Peristera Paschou; Nikolaos Siomos; Vassilis Amiridis; Volker Freudenthaler; George Georgoussis; Alexandra Tsekeri; Charikleia Meleti; Jonas Von Bismarck. EVE polarization lidar: ESA’s ground reference system for Aeolus L2A products Cal/Val. 2021, 1 .

AMA Style

Peristera Paschou, Nikolaos Siomos, Vassilis Amiridis, Volker Freudenthaler, George Georgoussis, Alexandra Tsekeri, Charikleia Meleti, Jonas Von Bismarck. EVE polarization lidar: ESA’s ground reference system for Aeolus L2A products Cal/Val. . 2021; ():1.

Chicago/Turabian Style

Peristera Paschou; Nikolaos Siomos; Vassilis Amiridis; Volker Freudenthaler; George Georgoussis; Alexandra Tsekeri; Charikleia Meleti; Jonas Von Bismarck. 2021. "EVE polarization lidar: ESA’s ground reference system for Aeolus L2A products Cal/Val." , no. : 1.

Preprint content
Published: 04 March 2021
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ESA supported airborne and ground-based campaigns constitute an essential element in the development and operation of satellite missions, providing the opportunity to test novel observation technologies, acquire representative data for the development of the mission concepts, processors and use cases, as well as in their calibration and validation phases once in orbit.

For the Aeolus Doppler Wind Lidar satellite mission, ESA has implemented a campaign programme that started in 2007 and has continued beyond the launch of the mission on 22. August 2018. Building on the successful WindVal-I and –II campaigns with DLR’s A2D and 2µm Doppler Wind Lidar systems on-board the DLR Falcon aircraft, a number of validation campaigns have been successfully implemented: WindVal-III in November 2018, AVATAR-E in May 2019, and AVATAR-I in September 2019. In addition, ESA supported the CNES pre-Stratéole-2/TAPAPA campaign with eight stratospheric balloons having been launched from the Seychelles in November/December 2019 providing unique upper level wind data in the Tropics. The validation by stratospheric balloons has been extended in the frame of a collaboration with Loon LLC for a test case covering the months August and September 2019.

As the largest impact of the Aeolus observations is expected in the Tropics, and in particular over the Tropical oceans, ESA, in close collaboration with NASA and European partners, is currently implementing a Tropical campaign in July 2021.  With its base in Cape Verde the activity comprises both airborne and ground-based activities addressing the tropical winds and aerosol validation, as well as a wide range of science objectives. The location is unique as it allows the study of the Saharan Aerosol layer, African Easterly Waves and Jets, the Tropical Easterly Jet, as well as deep convection in ITCZ and tropical cyclogenesis, with a focus on the impact of Saharan dust on micro-physics in tropical cloud systems. The campaign builds on remote and in-situ observations from aircraft (DLR Falcon-20, the Safire Falcon-20, the NASA DC-8 and an Aerovizija/UNG light aircraft) and drone systems, as well as an extensive aerosol and cloud measurement programme with a range of lidar, radar and radiometer systems coordinated by NOA.

This paper will provide a summary of the Aeolus campaign activities, focussing on the completed and planned post launch campaigns.

ACS Style

Thorsten Fehr; Vassilis Amiridis; Jonas von Bismarck; Sebastian Bley; Cyrille Flamant; Albert Hertzog; Christian Lemmerz; Griša Močnik; Tommaso Parrinello; Gail Skofronick-Jackson; Anne Grete Straume. Aeolus Calibration, Validation and Science Post-Launch Campaigns. 2021, 1 .

AMA Style

Thorsten Fehr, Vassilis Amiridis, Jonas von Bismarck, Sebastian Bley, Cyrille Flamant, Albert Hertzog, Christian Lemmerz, Griša Močnik, Tommaso Parrinello, Gail Skofronick-Jackson, Anne Grete Straume. Aeolus Calibration, Validation and Science Post-Launch Campaigns. . 2021; ():1.

Chicago/Turabian Style

Thorsten Fehr; Vassilis Amiridis; Jonas von Bismarck; Sebastian Bley; Cyrille Flamant; Albert Hertzog; Christian Lemmerz; Griša Močnik; Tommaso Parrinello; Gail Skofronick-Jackson; Anne Grete Straume. 2021. "Aeolus Calibration, Validation and Science Post-Launch Campaigns." , no. : 1.

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In this study, we present a comparison of the AEOLUS satellite L2A product with the retrievals of the ground-based lidar systems of EARLINET (European Aerosol Research Lidar Network), part the European Research Infrastructure for the observation of Aerosol, Clouds and Trace Gases (ACTRIS). Dedicated ground‐based measurements during AEOLUS overpasses have been performed among the 29 member stations since the beginning of the mission, however, we have included only the stations that have gathered a significant number of collocations in the analysis. The satellite timeseries we deployed covers the period 2019-2020 that correspond to the best available version of the satellite processing algorithms. We harvest the collocations using the following spacio-temporal criteria. Only overpasses that fall within a radius less than 100km around the station are included. Using this criterion, the AEOLUS L2A climatology is generated per station independently of the ground-based measurements. To isolate collocated data we reject all AEOLUS data with a time interval between the overpass and the central time of the ground-based measurement that is greater than 3 hours. The ground based lidar climatology is also computed per station. AEOLUS L2A products include aerosol extinction coefficient profiles and aerosol co-polar backscatter coefficient profiles from circularly polarized light emission. While the extinction profiles are directly comparable with the ground-based lidars, this is not the case for the backscatter profiles since AEOLUS cannot measure the cross polar component of the aerosol backscatter. The co-polar backscatter is close to the total backscatter only in the absence of depolarizing scatterers such as dust, pollen, volcanic ash, and cirrus ice crystals. Ground-based measurements are divided in two categories for the evaluation depending on whether aerosol depolarization measurements have been performed. If the particle linear depolarization ratio (PLDR) is available, it can be applied to convert the lidar total backscatter to an AOLUS-like co-polar backscatter coefficient. This category is applied for the direct evaluation of the satellite product. Cases that lack PLDR information assist to quantify the uncertainties introduced by using the AEOLUS co-polar backscatter as a substitute for the total backscatter. The analysis includes both an indirect climatological comparison and a direct collocation comparison between the ground based and satellite datasets. Via the collocation comparison, random and systematic uncertainties in the satellite product are identified and quantified. A climatological comparison can show the potential of AEOLUS to capture annual cycles despite its intrinsic random errors. In the future, the analysis will be further supported with auxiliary data such as sunphotometer measurements, aerosol classification flags, modeled backward trajectories, and satellite cloud fraction data.

ACS Style

Nikolaos Siomos; Antonis Gkikas; Holger Baars; Ulla Wandinger; Vasilis Amiridis; Peristera Paschou; EARLINET consortium. Investigating the performance of AEOLUS L2A products over Europe with EARLINET ground-based lidars. 2021, 1 .

AMA Style

Nikolaos Siomos, Antonis Gkikas, Holger Baars, Ulla Wandinger, Vasilis Amiridis, Peristera Paschou, EARLINET consortium. Investigating the performance of AEOLUS L2A products over Europe with EARLINET ground-based lidars. . 2021; ():1.

Chicago/Turabian Style

Nikolaos Siomos; Antonis Gkikas; Holger Baars; Ulla Wandinger; Vasilis Amiridis; Peristera Paschou; EARLINET consortium. 2021. "Investigating the performance of AEOLUS L2A products over Europe with EARLINET ground-based lidars." , no. : 1.

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In the last years, several Etna eruption events are documented, forming lava flows and explosive activity. The Pilot EO4D_ash – Earth observation data for detection, discrimination & distribution (4D) of volcanic ash of the e-shape project provides the PANhellenic GEophysical observatory of Antikythera (PANGEA) of the National Observatory of Athens (NOA), in Greece with near-real-time alerts from Etna volcano eruptions. These alerts are used in the PANGEA station to monitor and reveal the presence of volcanic particles above the area the days following an eruption, also the station is supported by a volcanic particle monitoring and forecasting warning system. In this work, we investigate the volcano eruption between 30 May and 6 June 2019 which affected the southern parts of Greece and reaching the Antikythera station. Due to the prevailing meteorological conditions, volcanic particles and gases followed an easterly direction and were dispersed towards Greece. FLEXPART dispersion model simulations confirm the volcanic plume transport from Etna towards PANGEA, mixing also with co-existing desert dust particles. Model simulations are evaluated with PollyXT lidar measurements performed at PANGEA and satellite-based SO2 observations from the TROPOspheric Monitoring Instrument onboard the Sentinel-5 Precursor (TROPOMI/S5P). This is the first time that Etna volcanic products are monitored at the Antikythera station, in Greece with implications for the investigation of their role in the Mediterranean weather and climate.

Acknowledgments: We acknowledge the support by EU H2020 E-shape project (Grant Agreement n. 820852). Also, this research was supported by data and services obtained from the PANhellenic Geophysical Observatory of Antikythera (PANGEA) of the National Observatory of Athens (NOA), Greece, and by the project “PANhellenic infrastructure for Atmospheric Composition and climatE change” (MIS 5021516) which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme "Competitiveness, Entrepreneurship and Innovation" (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund). NOA team acknowledges the support of the Stavros Niarchos Foundation (SNF).

ACS Style

Anna Kampouri; Vassilis Amiridis; Stavros Solomos; Anna Gialitaki; Eleni Marinou; Christos Spyrou; Aristeidis K. Georgoulias; Dimitris Akritidis; Nikolaos Papagiannopoulos; Lucia Mona; Simona Scollo; Ioannis Pytharoulis; Theodore Karacostas; Prodromos Zanis. Investigation of volcanic emissions in Antikythera PANGEA station using near-real-time alerts. 2021, 1 .

AMA Style

Anna Kampouri, Vassilis Amiridis, Stavros Solomos, Anna Gialitaki, Eleni Marinou, Christos Spyrou, Aristeidis K. Georgoulias, Dimitris Akritidis, Nikolaos Papagiannopoulos, Lucia Mona, Simona Scollo, Ioannis Pytharoulis, Theodore Karacostas, Prodromos Zanis. Investigation of volcanic emissions in Antikythera PANGEA station using near-real-time alerts. . 2021; ():1.

Chicago/Turabian Style

Anna Kampouri; Vassilis Amiridis; Stavros Solomos; Anna Gialitaki; Eleni Marinou; Christos Spyrou; Aristeidis K. Georgoulias; Dimitris Akritidis; Nikolaos Papagiannopoulos; Lucia Mona; Simona Scollo; Ioannis Pytharoulis; Theodore Karacostas; Prodromos Zanis. 2021. "Investigation of volcanic emissions in Antikythera PANGEA station using near-real-time alerts." , no. : 1.

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For the in-orbit calibration and validation of the Aeolus products, ESA organized the Aeolus Tropical campaign, which will take place on June-July 2021 at Cape Verde region. During the campaign, Aeolus underfights will be performed with several aircrafts (by DLR, NASA, LATMOS, and the University of Nova Gorica (UNG)) and advanced ground-based instrumentation will be deployed in Mindelo island within ASKOS (https://askos.space.noa.gr/) experiment. ASKOS observations will provide an unprecedented dataset for the aerosol and wind conditions in the region, in order to provide reference values for the Cal/Val of the mission. Apart from the main aerosol Cal/Val objective of ASKOS, the foreseen synergistic activities will provide a wealth of information to address scientific questions posed by the participating groups on dust characterization, transportation and it’s impact of radiation and cloud formation.

Here, we report on the status of the ASKOS preparations for the evaluation of the aerosol and cloud product, focusing on the instrumentation requirements and availability, as well as the engagement of the scientific community so far. ASKOS will deploy advanced ground-based and airborne remote sensing and in-situ instrumentation, including the full ACTRIS aerosol and cloud remote sensing/in-situ facilities and airborne in-situ sensors to be operated on drones and/or aircrafts. The main ground-based remote sensing instrumentation in Cape Verde will consist of sophisticated lidar systems, including the EVE lidar, a circular polarization system that is tailored to mimic the Aeolus measurement from ground, the multi-wavelength Polly-XT and the WALL-E prototype for detecting particle orientation. The instrumentation will also include sun-photometers such as AERONET-CIMEL, but also polarimeters to advance microphysical retrievals for non-spherical particles such as dust. Cloud remote sensors including a cloud radar and a microwave radiometer will operate in parallel along with meteorological radiosondes. In-situ sensors at surface and onboard UAVs and light aircrafts will be available. ASKOS will be fully supported by several operational modeling simulations for meteorological and atmospheric composition forecasting. ASKOS will remain open to contributions from other communities and research groups and more synergies will be pursued in the future.

 

ACS Style

Eleni Marinou; Vasslis Amiridis; Ioanna Mavropoulou; Holger Baars; Stelios Kazadzis; Marco Rosoldi; Dragos Ene; Africa Barreto; Stefano Casadio; Cordula Zenk; Jean Sciare; Grisa Mocnik; Konrad Kandler; Jan-Berend Stuut; Sergio Rodrigez; Peter Knipertz; Thomas Rutz; Mika Komppula; Vassiliki Daskalopoulou; George Hloupis; Askos Team. The ASKOS experiment for the validation of Aeolus L2A aerosol product . 2021, 1 .

AMA Style

Eleni Marinou, Vasslis Amiridis, Ioanna Mavropoulou, Holger Baars, Stelios Kazadzis, Marco Rosoldi, Dragos Ene, Africa Barreto, Stefano Casadio, Cordula Zenk, Jean Sciare, Grisa Mocnik, Konrad Kandler, Jan-Berend Stuut, Sergio Rodrigez, Peter Knipertz, Thomas Rutz, Mika Komppula, Vassiliki Daskalopoulou, George Hloupis, Askos Team. The ASKOS experiment for the validation of Aeolus L2A aerosol product . . 2021; ():1.

Chicago/Turabian Style

Eleni Marinou; Vasslis Amiridis; Ioanna Mavropoulou; Holger Baars; Stelios Kazadzis; Marco Rosoldi; Dragos Ene; Africa Barreto; Stefano Casadio; Cordula Zenk; Jean Sciare; Grisa Mocnik; Konrad Kandler; Jan-Berend Stuut; Sergio Rodrigez; Peter Knipertz; Thomas Rutz; Mika Komppula; Vassiliki Daskalopoulou; George Hloupis; Askos Team. 2021. "The ASKOS experiment for the validation of Aeolus L2A aerosol product ." , no. : 1.

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The new polarization lidar nicknamed “WALL-E” is designed to monitor dust orientation. Dust orientation has not been extensively investigated for the Earth’s atmosphere, where dust is considered to be randomly-oriented. For monitoring dust orientation, the new polarization lidar emits linearly- and elliptically-polarized light at 1064 nm and detects the linear and circular polarization of the backscattered light. This is done with two lasers emitting in an interleaved fashion, and two telescopes collecting the backscattered light from both lasers. The measurements are performed at variable viewing angles and provide direct flags of dust orientation, along with more detailed information on particle microphysics. The first measurements for dust in Athens are presented.

 

 

Acknowledgements. The work is supported by the European Research Council under the European Community’s Horizon 2020 research and
innovation framework program/ERC grant agreement 725698 (D-TECT). We acknowledge PRACE for awarding us access to MareNostrum
at Barcelona Supercomputing Center (BSC), Spain. The work was supported by computational time granted from the Greek Research &
Technology Network (GRNET) in the National HPC facility - ARIS - under project ID pa170906-ADDAPAS, pr005038-REMOD and pr009019-EXEED.

ACS Style

Alexandra Tsekeri; Volker Freudenthaler; Vassilis Amiridis; George Doxastakis; Alexandros Louridas; George Georgoussis; Spiros Metallinos; Josef Gasteiger; Nikolaos Siomos; Peristera Paschou; Thanasis Georgiou; George Tsaknakis; Christos Evangelatos; Ioannis Binietoglou. Polarization lidar for detecting dust orientation: first measurements. 2021, 1 .

AMA Style

Alexandra Tsekeri, Volker Freudenthaler, Vassilis Amiridis, George Doxastakis, Alexandros Louridas, George Georgoussis, Spiros Metallinos, Josef Gasteiger, Nikolaos Siomos, Peristera Paschou, Thanasis Georgiou, George Tsaknakis, Christos Evangelatos, Ioannis Binietoglou. Polarization lidar for detecting dust orientation: first measurements. . 2021; ():1.

Chicago/Turabian Style

Alexandra Tsekeri; Volker Freudenthaler; Vassilis Amiridis; George Doxastakis; Alexandros Louridas; George Georgoussis; Spiros Metallinos; Josef Gasteiger; Nikolaos Siomos; Peristera Paschou; Thanasis Georgiou; George Tsaknakis; Christos Evangelatos; Ioannis Binietoglou. 2021. "Polarization lidar for detecting dust orientation: first measurements." , no. : 1.

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Biotic and abiotic processes that form, alter, transport, and remineralize particulate organic carbon, silicon, calcium carbonate, and other minor and trace chemical species in the water column are central to the ocean’s ecological and biogeochemical functioning and of fundamental importance to the ocean carbon cycle. Sinking particulate matter is the major vehicle for exporting carbon from the sea surface to the deep sea. During its transit towards the sea floor, most particulate organic carbon (POC) is returned to inorganic form and redistributed in the water column. This redistribution determines the surface concentration of dissolved CO2, and hence the rate at which the ocean can absorb CO2 from the atmosphere. The ability to predict quantitatively the depth profile of remineralization is therefore critical to deciphering the response of the global carbon cycle to natural and human-induced changes.

Aiming to investigate the significant biogeochemical and ecological features and provide new insights on the sources and cycles of sinking particulate matter, a mooring line of five sediment traps was deployed from 2006 to 2015 (with some gap periods) at 5 successive water column depths (700, 1200, 2000, 3200 and 4300 m) in the SE Ionian Sea, northeastern Mediterranean (‘NESTOR’ site). We have examined the long-term records of downward fluxes for Corg, Ntot, δ13Corg and δ15Ntot, along with the associated ballast minerals (opal, lithogenics and CaCO3), lipid biomarkers, Chl-a and PP rates, phytoplankton composition, nutrient dynamics and atmospheric deposition.  

The satellite-derived seasonal and interannual variability of phytoplankton metrics (biomass and phenology) and atmospheric deposition (meteorology and air masses origin) was examined for the period of the sediment trap experiment. Regarding the atmospheric deposition, synergistic opportunities using Earth Observation satellite lidar and radiometer systems are proposed (e.g. Cloud‐Aerosol Lidar with Orthogonal Polarization - CALIOP, Moderate Resolution Imaging Spectroradiometer - MODIS), aiming towards a four‐dimensional exploitation of atmospheric aerosol loading (e.g. Dust Optical Depth) in the study area.

Our main goals are to: i) develop a comprehensive knowledge of carbon fluxes and associated mineral ballast fluxes from the epipelagic to the mesopelagic and bathypelagic layers, ii) elucidate the mechanisms governing marine productivity and carbon export and sequestration to depth and iii) shed light on the impact of atmospheric forcing and deposition in respect to regional and large scale circulation patterns and climate variability and the prevailing oceanographic processes (internal variability).

Acknowledgments

We acknowledge support of this work by the Action ‘National Network on Climate Change and its Impacts – CLIMPACT’, funded by the Public Investment Program of Greece (GSRT, Ministry of Development and Investments).

ACS Style

Alexandra Gogou; Constantine Parinos; Spyros Stavrakakis; Emmanouil Proestakis; Maria Kanakidou; Dionysios E Raitsos; Harilaos Kontoyiannis; Dimitrios Velaoras; Anastasia Christidi; Elisavet Skampa; Maria Triantaphyllou; Georgia Asimakopoulou; Giuseppe Civitarese; Eva Krasakopoulou; Alexandra Pavlidou; Ekaterini Souvermezoglou; Vassilis Amiridis; Nikos Mihalopoulos; Aristomenis P Karageorgis; Vassileios Lykousis. Biogeochemical and ecological features of sinking particulate matter in the deep Ionian Sea (E. Mediterranean) during a 10-year time series study: impacts of atmospheric and oceanographic variabilities on carbon production and sequestration. 2021, 1 .

AMA Style

Alexandra Gogou, Constantine Parinos, Spyros Stavrakakis, Emmanouil Proestakis, Maria Kanakidou, Dionysios E Raitsos, Harilaos Kontoyiannis, Dimitrios Velaoras, Anastasia Christidi, Elisavet Skampa, Maria Triantaphyllou, Georgia Asimakopoulou, Giuseppe Civitarese, Eva Krasakopoulou, Alexandra Pavlidou, Ekaterini Souvermezoglou, Vassilis Amiridis, Nikos Mihalopoulos, Aristomenis P Karageorgis, Vassileios Lykousis. Biogeochemical and ecological features of sinking particulate matter in the deep Ionian Sea (E. Mediterranean) during a 10-year time series study: impacts of atmospheric and oceanographic variabilities on carbon production and sequestration. . 2021; ():1.

Chicago/Turabian Style

Alexandra Gogou; Constantine Parinos; Spyros Stavrakakis; Emmanouil Proestakis; Maria Kanakidou; Dionysios E Raitsos; Harilaos Kontoyiannis; Dimitrios Velaoras; Anastasia Christidi; Elisavet Skampa; Maria Triantaphyllou; Georgia Asimakopoulou; Giuseppe Civitarese; Eva Krasakopoulou; Alexandra Pavlidou; Ekaterini Souvermezoglou; Vassilis Amiridis; Nikos Mihalopoulos; Aristomenis P Karageorgis; Vassileios Lykousis. 2021. "Biogeochemical and ecological features of sinking particulate matter in the deep Ionian Sea (E. Mediterranean) during a 10-year time series study: impacts of atmospheric and oceanographic variabilities on carbon production and sequestration." , no. : 1.

Journal article
Published: 26 February 2021 in Remote Sensing
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We use the Generalized Retrieval of Aerosol Surface Properties algorithm (GRASP) to compare with dust concentration profiles derived from the NMME-DREAM model for a specific dust episode. The GRASP algorithm provides the possibility of deriving columnar and vertically-resolved aerosol properties from a combination of lidar and sun-photometer observations. Herein, we apply GRASP for analysis of a Saharan dust outburst observed during the “PREparatory: does dust TriboElectrification affect our ClimaTe” campaign (PreTECT) that took place at the North coast of Crete, at the Finokalia ACTRIS station. GRASP provides column-averaged and vertically resolved microphysical and optical properties of the particles. The retrieved dust concentration profiles are compared with modeled concentration profiles derived from the NMME-DREAM dust model. To strengthen the results, we use dust concentration profiles from the POlarization-LIdar PHOtometer Networking method (POLIPHON). A strong underestimation of the maximum dust concentration is observed from the NMME-DREAM model. The reported differences between the retrievals and the model indicate a high potential of the GRASP algorithm for future studies of dust model evaluation.

ACS Style

Dimitra Konsta; Alexandra Tsekeri; Stavros Solomos; Nikolaos Siomos; Anna Gialitaki; Eleni Tetoni; Anton Lopatin; Philippe Goloub; Oleg Dubovik; Vassilis Amiridis; Panagiotis Nastos. The Potential of GRASP/GARRLiC Retrievals for Dust Aerosol Model Evaluation: Case Study during the PreTECT Campaign. Remote Sensing 2021, 13, 873 .

AMA Style

Dimitra Konsta, Alexandra Tsekeri, Stavros Solomos, Nikolaos Siomos, Anna Gialitaki, Eleni Tetoni, Anton Lopatin, Philippe Goloub, Oleg Dubovik, Vassilis Amiridis, Panagiotis Nastos. The Potential of GRASP/GARRLiC Retrievals for Dust Aerosol Model Evaluation: Case Study during the PreTECT Campaign. Remote Sensing. 2021; 13 (5):873.

Chicago/Turabian Style

Dimitra Konsta; Alexandra Tsekeri; Stavros Solomos; Nikolaos Siomos; Anna Gialitaki; Eleni Tetoni; Anton Lopatin; Philippe Goloub; Oleg Dubovik; Vassilis Amiridis; Panagiotis Nastos. 2021. "The Potential of GRASP/GARRLiC Retrievals for Dust Aerosol Model Evaluation: Case Study during the PreTECT Campaign." Remote Sensing 13, no. 5: 873.

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Dust orientation is an ongoing investigation in recent years. Its potential proof will be a paradigm shift for dust remote sensing, invalidating the currently used simplifications of randomly-oriented particles. Vertically-resolved measurements of dust orientation can be acquired with a polarization lidar designed to target the off-diagonal elements of the backscatter matrix which are non-zero only when the particles are oriented. Building on previous studies, we constructed a lidar system emitting linearly- and elliptically-polarized light at 1064 nm and detecting the linear and circular polarization of the backscattered light. Its measurements provide direct flags of dust orientation, as well as more detailed information of the particle microphysics. The system also employs the capability to acquire measurements at varying viewing angles. Moreover, in order to achieve good signal-to-noise-ratio in short measurement times the system is equipped with two laser sources emitting in interleaved fashion, and two telescopes for detecting the backscattered light from both lasers. Herein we provide a description of the optical and mechanical parts of this new lidar system, the scientific and technical objectives of its design, and the calibration methodologies tailored for the measurements of oriented dust particles. We also provide the first measurements of the system.

ACS Style

Alexandra Tsekeri; Vassilis Amiridis; Alexandros Louridas; George Georgoussis; Volker Freudenthaler; Spiros Metallinos; George Doxastakis; Josef Gasteiger; Nikolaos Siomos; Peristera Paschou; Thanasis Georgiou; George Tsaknakis; Christos Evangelatos; Ioannis Binietoglou. Polarization lidar for detecting dust orientation: System design and calibration. 2021, 2021, 1 -36.

AMA Style

Alexandra Tsekeri, Vassilis Amiridis, Alexandros Louridas, George Georgoussis, Volker Freudenthaler, Spiros Metallinos, George Doxastakis, Josef Gasteiger, Nikolaos Siomos, Peristera Paschou, Thanasis Georgiou, George Tsaknakis, Christos Evangelatos, Ioannis Binietoglou. Polarization lidar for detecting dust orientation: System design and calibration. . 2021; 2021 ():1-36.

Chicago/Turabian Style

Alexandra Tsekeri; Vassilis Amiridis; Alexandros Louridas; George Georgoussis; Volker Freudenthaler; Spiros Metallinos; George Doxastakis; Josef Gasteiger; Nikolaos Siomos; Peristera Paschou; Thanasis Georgiou; George Tsaknakis; Christos Evangelatos; Ioannis Binietoglou. 2021. "Polarization lidar for detecting dust orientation: System design and calibration." 2021, no. : 1-36.

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ACS Style

Alexandra Tsekeri; Vassilis Amiridis; Alexandros Louridas; George Georgoussis; Volker Freudenthaler; Spiros Metallinos; George Doxastakis; Josef Gasteiger; Nikolaos Siomos; Peristera Paschou; Thanasis Georgiou; George Tsaknakis; Christos Evangelatos; Ioannis Binietoglou. Supplementary material to "Polarization lidar for detecting dust orientation: System design and calibration". 2021, 1 .

AMA Style

Alexandra Tsekeri, Vassilis Amiridis, Alexandros Louridas, George Georgoussis, Volker Freudenthaler, Spiros Metallinos, George Doxastakis, Josef Gasteiger, Nikolaos Siomos, Peristera Paschou, Thanasis Georgiou, George Tsaknakis, Christos Evangelatos, Ioannis Binietoglou. Supplementary material to "Polarization lidar for detecting dust orientation: System design and calibration". . 2021; ():1.

Chicago/Turabian Style

Alexandra Tsekeri; Vassilis Amiridis; Alexandros Louridas; George Georgoussis; Volker Freudenthaler; Spiros Metallinos; George Doxastakis; Josef Gasteiger; Nikolaos Siomos; Peristera Paschou; Thanasis Georgiou; George Tsaknakis; Christos Evangelatos; Ioannis Binietoglou. 2021. "Supplementary material to "Polarization lidar for detecting dust orientation: System design and calibration"." , no. : 1.

Journal article
Published: 09 February 2021 in Remote Sensing
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Atmospheric-chemical coupled models usually parameterize sea-salt aerosol (SSA) emissions using whitecap fraction estimated considering only wind speed and ignoring sea state. This approach may introduce inaccuracies in SSA simulation. This study aims to assess the impact of sea state on SSA modeling, applying a new parameterization for whitecap fraction estimation based on wave age, calculated by the ratio between wave phase velocity and wind speed. To this end, the new parameterization was incorporated in the coupled Chemical Hydrological Atmospheric Ocean wave modeling System (CHAOS). CHAOS encompasses the wave model (WAM) two-way coupled through the OASIS3-MCT coupler with the Advanced Weather Research and Forecasting model coupled with Chemistry (WRF-ARW-Chem) and, thus, enabling the concurrent simulation of SSAs, wind speed and wave phase velocity. The simulation results were evaluated against in-situ and lidar measurements at 2 stations in Greece (Finokalia on 4 and 15 July 2014 and Antikythera-PANGEA on 15 September 2018). The results reveal significant differences between the parameterizations with the new one offering a more realistic representation of SSA levels in some layers of the lower atmosphere. This is attributed to the enhancement of the bubble-bursting mechanism representation with air-sea processes controlling whitecap fraction. Our findings also highlight the contribution of fresh wind-generated waves to SSA modeling.

ACS Style

George Varlas; Eleni Marinou; Anna Gialitaki; Nikolaos Siomos; Konstantinos Tsarpalis; Nikolaos Kalivitis; Stavros Solomos; Alexandra Tsekeri; Christos Spyrou; Maria Tsichla; Anna Kampouri; Vassilis Vervatis; Elina Giannakaki; Vassilis Amiridis; Nikolaos Mihalopoulos; Anastasios Papadopoulos; Petros Katsafados. Assessing Sea-State Effects on Sea-Salt Aerosol Modeling in the Lower Atmosphere Using Lidar and In-Situ Measurements. Remote Sensing 2021, 13, 614 .

AMA Style

George Varlas, Eleni Marinou, Anna Gialitaki, Nikolaos Siomos, Konstantinos Tsarpalis, Nikolaos Kalivitis, Stavros Solomos, Alexandra Tsekeri, Christos Spyrou, Maria Tsichla, Anna Kampouri, Vassilis Vervatis, Elina Giannakaki, Vassilis Amiridis, Nikolaos Mihalopoulos, Anastasios Papadopoulos, Petros Katsafados. Assessing Sea-State Effects on Sea-Salt Aerosol Modeling in the Lower Atmosphere Using Lidar and In-Situ Measurements. Remote Sensing. 2021; 13 (4):614.

Chicago/Turabian Style

George Varlas; Eleni Marinou; Anna Gialitaki; Nikolaos Siomos; Konstantinos Tsarpalis; Nikolaos Kalivitis; Stavros Solomos; Alexandra Tsekeri; Christos Spyrou; Maria Tsichla; Anna Kampouri; Vassilis Vervatis; Elina Giannakaki; Vassilis Amiridis; Nikolaos Mihalopoulos; Anastasios Papadopoulos; Petros Katsafados. 2021. "Assessing Sea-State Effects on Sea-Salt Aerosol Modeling in the Lower Atmosphere Using Lidar and In-Situ Measurements." Remote Sensing 13, no. 4: 614.