scholarly journals 3D evolution of Saharan dust transport towards Europe based on a 9-year EARLINET-optimized CALIPSO dataset

2016 ◽  
Author(s):  
Eleni Marinou ◽  
Vassilis Amiridis ◽  
Ioannis Binietoglou ◽  
Stavros Solomos ◽  
Emannouil Proestakis ◽  
...  
Keyword(s):  
Saharan Dust ◽  
Winter Period ◽  
Dust Transport ◽  
North West ◽  
Ice Nuclei ◽  
Potential Applications ◽  
Lidar Ratio ◽  
The Mediterranean ◽  
Dust Evolution ◽  
First Time

Abstract. In this study we utilize a new dust product developed using CALIPSO observations and EARLINET measurements and methods to provide a 3D multiyear analysis on the evolution of Saharan dust over North Africa and Europe. The product utilizes CALIPSO L2 backscatter product corrected with a depolarization-based method to separate pure dust in external aerosol mixtures and an adjusted Saharan dust lidar ratio based on long-term EARLINET measurements. The methodology is applied on a nine-year CALIPSO dataset (2007–2015) and the results are analysed here to reveal for the first time the 3D dust evolution and the seasonal patterns of dust over its transportation paths from the Sahara towards the Mediterranean and Continental Europe. During spring, dust is uniformly distributed in the horizontal over the Sahara desert. The dust transport over the Mediterranean Sea results on mean Dust Optical Depth (DOD) values of 0.1. During summer, the dust activity is mostly shifted to the western part of the desert where mean DOD near the source is up to 0.6. Elevated dust plumes with mean extinction values between 10–75 Mm−1 are observed throughout the year at various heights between 2–6 km, extending up to latitudes of 40° N. Dust advection is identified even at latitudes of about 60° N, but this is due to rare events of episodic nature. Dust plumes of high DOD are also observed above Balkans during winter period and above North-West Europe during autumn at heights between 2–4 km, reaching mean extinction values up to 50 Mm−1. The dataset is considered unique with respect to its potential applications, including the evaluation of dust transport models and the estimation of cloud condensation and ice nuclei concentration profiles (CCN/IN). Finally, the product can be used to study dust dynamics during transportation, since it is capable of revealing even fine dynamical features such as the particle uplifting and deposition on European mountainous ridges such as Alps and Carpathian.

scholarly journals Three-dimensional evolution of Saharan dust transport towards Europe based on a 9-year EARLINET-optimized CALIPSO dataset

2017 ◽  
Vol 17 (9) ◽  
pp. 5893-5919 ◽  
Author(s):  
Eleni Marinou ◽  
Vassilis Amiridis ◽  
Ioannis Binietoglou ◽  
Athanasios Tsikerdekis ◽  
Stavros Solomos ◽  
...  
Keyword(s):  
Cloud Condensation Nuclei ◽  
Three Dimensional ◽  
Satellite Observation ◽  
Saharan Dust ◽  
Winter Period ◽  
Dust Transport ◽  
The Balkans ◽  
Potential Applications ◽  
The Mediterranean ◽  
Dust Evolution

Abstract. In this study we use a new dust product developed using CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) observations and EARLINET (European Aerosol Research Lidar Network) measurements and methods to provide a 3-D multiyear analysis on the evolution of Saharan dust over North Africa and Europe. The product uses a CALIPSO L2 backscatter product corrected with a depolarization-based method to separate pure dust in external aerosol mixtures and a Saharan dust lidar ratio (LR) based on long-term EARLINET measurements to calculate the dust extinction profiles. The methodology is applied on a 9-year CALIPSO dataset (2007–2015) and the results are analyzed here to reveal for the first time the 3-D dust evolution and the seasonal patterns of dust over its transportation paths from the Sahara towards the Mediterranean and Continental Europe. During spring, the spatial distribution of dust shows a uniform pattern over the Sahara desert. The dust transport over the Mediterranean Sea results in mean dust optical depth (DOD) values up to 0.1. During summer, the dust activity is mostly shifted to the western part of the desert where mean DOD near the source is up to 0.6. Elevated dust plumes with mean extinction values between 10 and 75 Mm−1 are observed throughout the year at various heights between 2 and 6 km, extending up to latitudes of 40° N. Dust advection is identified even at latitudes of about 60° N, but this is due to rare events of episodic nature. Dust plumes of high DOD are also observed above the Balkans during the winter period and above northwest Europe during autumn at heights between 2 and 4 km, reaching mean extinction values up to 50 Mm−1. The dataset is considered unique with respect to its potential applications, including the evaluation of dust transport models and the estimation of cloud condensation nuclei (CCN) and ice nuclei (IN) concentration profiles. Finally, the product can be used to study dust dynamics during transportation, since it is capable of revealing even fine dynamical features such as the particle uplifting and deposition on European mountainous ridges such as the Alps and Carpathian Mountains.

scholarly journals Lidar Measuremnt on Dust Transport from the Saharan Desert to the Iran Plateau

2020 ◽  
Vol 237 ◽  
pp. 02020
Author(s):  
Hossein Panahifar ◽  
Ruhollah Moradhaseli ◽  
Hadi Bourzoie ◽  
Mahdi Gholami ◽  
Hamid Reza Khalesifard
Keyword(s):  
Trajectory Analysis ◽  
Saharan Dust ◽  
Dust Particles ◽  
Raman Lidar ◽  
Dust Layer ◽  
Mean Values ◽  
Dust Transport ◽  
Lidar Ratio ◽  
532 Nm ◽  
Iran Plateau

Optical properties of long-range Saharan dust particles transported to the Iran Plateau have been investigated. The results were derived from the measurements of a dual-wavelength Depolarized backscatter/Raman lidar and a Cimel CE318-2 sunphotometer. Observations were performed in Zanjan, Northwest Iran. The backward trajectory analysis show that the lofted dust plumes come from the Saharan desert and travel along Mediterranean Sea and Turkey toward Iran. The lidar ratio within the lofted dust layer has been found with mean values of 50 sr at 532 nm. For the depolarization ratio, mean values of 25% have been found.

scholarly journals First triple-wavelength lidar observations of depolarization and extinction-to-backscatter ratios of Saharan dust

2021 ◽  
Author(s):  
Moritz Haarig ◽  
Albert Ansmann ◽  
Ronny Engelmann ◽  
Holger Baars ◽  
Dietrich Althausen ◽  
...  
Keyword(s):  
Saharan Dust ◽  
Depolarization Ratio ◽  
Spectral Slope ◽  
Desert Dust ◽  
Lidar Measurements ◽  
Lidar Ratio ◽  
Linear Depolarization Ratio ◽  
First Time ◽  
Dust Case ◽  
Lidar Observations

Abstract. Two Saharan dust layers observed over Leipzig in February and March 2021 were used to provide the first ever lidar measurements of the extinction coefficient at 1064 nm for desert dust. The advanced multiwavelength Raman polarization lidar was able to provide, for the first time, the lidar ratio (extinction-to-backscatter ratio) and particle linear depolarization ratio at all three classical lidar wavelengths (355, 532 and 1064 nm). The pure dust conditions during the first event exhibit lidar ratios of 47±8, 50±5 and 63±13 sr and particle linear depolarization ratios of 0.260±0.026, 0.298±0.017 and 0.214±0.025 at the wavelengths of 355, 532 and 1064 nm, respectively. The second, slightly polluted dust case shows a similar spectral behavior with values of the lidar ratio of 52±8, 47±5 and 61±10 sr and the depolarization ratio of 0.188±0.053, 0.270±0.017 and 0.242±0.007 at 355, 532 and 1064 nm, respectively. The results were compared to AERONET v3 inversions and GRASP retrievals at six and seven wavelengths, which could reproduce the spectral slope of the lidar ratio from 532 to 1064 nm. The spectral slope of the particle linear depolarization ratio could not be reproduced by the AERONET inversions, especially at 1064 nm.

scholarly journals On the Occurrence of Parablennius Sanguinolentus (Pisces: Blenniidae) on the Portuguese Coast

1993 ◽  
Vol 73 (2) ◽  
pp. 465-467 ◽  
Author(s):  
Emanuel J. Gonçalves ◽  
Vitor C. Almada ◽  
Armando J. Almeida ◽  
Rui F. De Oliveira
Keyword(s):  
Present Finding ◽  
Atlantic Coast ◽  
Fish Fauna ◽  
Bay Of Biscay ◽  
North West ◽  
Portuguese Coast ◽  
The North ◽  
Mainland Portugal ◽  
The Mediterranean ◽  
First Time

In this paper we report for the first time the occurrence of Parablennius sanguinolentus in mainland Portuguese waters. Since this species is common in the Mediterranean and in the Bay of Biscay, there appears to be a distributional gap along the Portuguese coast. The present finding, together with recent data on the occurrence of several other blenniids in the Atlantic coast of the Iberian Peninsula, formerly supposed to be Mediterranean endemics, stresses the urgent need for detailed zoogeographical investigations on the inshore fish fauna of south-west Europe.Parablennius sanguinolentus (Pallas, 1811) is widespread in the Mediterranean (Zander, 1986). On the Atlantic coast of Europe, however, it was known only from the Bay of Biscay where it is abundant in some places (Motos & Ibañez, 1979), from the north-west coast of Spain (Devesa et al., 1979) and recently from the Atlantic coast of Andalucía (Spain) (Rubio, 1991). It is also very common in the Azores, Madeira and Canary Islands if one assumes that P. parvicornis (Valenciennes, 1836) belongs to the same species, but this is as yet an unresolved issue (Zander, 1979; Almeida & Harmelin-Vivien, 1983; Bath, 1990; Santos, 1992). Although Zander (1986) presented a distributional map that includes the mainland Portuguese coast, no report on the occurrence of this species was known for this area. In a survey of the literature on the blennioid fishes occurring in Portuguese waters, we could not find a single citation that could possibly be ascribed to P. sanguinolentus for mainland Portugal (Oliveira et al., 1992).

scholarly journals Modelling Saharan dust transport into the Mediterranean basin with CMAQ

2013 ◽  
Vol 70 ◽  
pp. 337-350 ◽  
Author(s):  
David de la Paz ◽  
Michel Vedrenne ◽  
Rafael Borge ◽  
Julio Lumbreras ◽  
Juan Manuel de Andrés ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Saharan Dust ◽  
Dust Transport ◽  
The Mediterranean ◽  
The Mediterranean Basin

scholarly journals Interpreting elevated space-borne HCHO columns over the Mediterranean Sea using the OMI sensor

2011 ◽  
Vol 11 (24) ◽  
pp. 12787-12798 ◽  
Author(s):  
A. Sabolis ◽  
N. Meskhidze ◽  
G. Curci ◽  
P. I. Palmer ◽  
B. Gantt
Keyword(s):  
Mediterranean Sea ◽  
Hot Spot ◽  
Urban Atmosphere ◽  
Saharan Dust ◽  
Ozone Monitoring Instrument ◽  
Remotely Sensed Data ◽  
Vertical Column ◽  
Dust Transport ◽  
Wide Range ◽  
The Mediterranean

Abstract. Formaldehyde (HCHO) is an oxidation product of a wide range of volatile organic compounds (VOCs) and important atmospheric constituent found in both the polluted urban atmosphere and remote background sites. In this study, remotely sensed data of HCHO vertical column densities are analyzed over the Mediterranean Sea using the Ozone Monitoring Instrument (OMI). Data analysis indicates a marked seasonal cycle with a summer maximum and winter minimum confined to the marine environment during a three year period (2005–2007) examined. A possible retrieval artifact associated with Saharan dust transport over the region is explored by changing intensity of Saharan dust sources in GEOS-Chem following the recommendation of Generoso et al. (2008). Recalculated air mass factors (AMF), based on the new values of aerosol loadings, lead to a reduction of the summertime "hot spot" in OMI retrieval of HCHO vertical columns over the Mediterranean Sea; however, even after the correction, enhanced values are still present in this region. To explain these values, marine biogenic sources of VOCs are examined. Calculations indicate that emission of phytoplankton-produced isoprene is not likely to explain the enhanced HCHO vertical columns over the Mediterranean Sea. Model simulations in conjunction with measurements studies may be required to fully explore the complex mechanism of HCHO formation over the Mediterranean and its implications for the air quality in the region.

scholarly journals Process studies at the air-sea interface after atmospheric deposition in the Mediterranean Sea: objectives and strategy of the PEACETIME oceanographic campaign (May–June 2017)

2020 ◽  
Author(s):  
Cécile Guieu ◽  
Fabrizio D'Ortenzio ◽  
François Dulac ◽  
Vincent Taillandier ◽  
Andrea Doglioli ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Mediterranean Sea ◽  
Saharan Dust ◽  
Anthropogenic Sources ◽  
Dust Deposition ◽  
Process Studies ◽  
In Situ Observations ◽  
The Mediterranean ◽  
First Time

Abstract. In spring, the Mediterranean Sea, a well-stratified low nutrient low chlorophyll region, receives atmospheric deposition both desert dust from the Sahara and airborne particles from anthropogenic sources. Such deposition translates into a supply of new nutrients and trace metals for the surface waters that likely impact biogeochemical cycles. However, the quantification of the impacts and the processes involved are still far from being assessed in situ. In this paper, we provide a state of the art regarding dust deposition and its impact on the Mediterranean Sea biogeochemistry and we describe in this context the objectives and strategy of the PEACETIME project and cruise, entirely dedicated to filling this knowledge gap. Our strategy to go a step forward than in previous approaches in understanding these impacts by catching a real deposition event at sea is detailed. The PEACETIME oceanographic campaign took place in May–June 2017 and we describe how we were able to successfully adapt the planned transect in order to sample a Saharan dust deposition event, thanks to a dedicated strategy, so-called Fast Action. That was successful, providing, for the first time in our knowledge, a coupled atmospheric and oceanographic sampling before, during and after an atmospheric deposition event. Atmospheric and marine in situ observations and process studies have been conducted in contrasted area and we summarize the work performed at sea, the type of data acquired and their valorization in the papers published in the special issue.

scholarly journals Remote sensing of aerosols over the oceans using MSG/SEVIRI imagery

2005 ◽  
Vol 23 (12) ◽  
pp. 3561-3568 ◽  
Author(s):  
F. Thieuleux ◽  
C. Moulin ◽  
F. M. Bréon ◽  
F. Maignan ◽  
J. Poitou ◽  
...  
Keyword(s):  
Optical Thickness ◽  
Saharan Dust ◽  
Dust Transport ◽  
High Frequencies ◽  
Full Resolution ◽  
Fast Processing ◽  
Long Time ◽  
The Mediterranean ◽  
Good Agreement

Abstract. The SEVIRI instrument on board Meteosat Second Generation (MSG) offers new capabilities to monitor aerosol transport over the Atlantic and the Mediterranean at high temporal and spatial resolutions, in particular, Saharan dust from North Africa, biomass-burning aerosols from subtropical Africa and pollution from Europe. An inversion technique was developed to estimate both aerosol optical thickness and Angström coefficients from SEVIRI measurements at 0.63 and 0.81 µm. This method relies on an optimized set of aerosol models to ensure a fast processing of full-resolution MSG images and to allow the processing of long time series. SEVIRI images for slots 45, 49 and 53 (11:15, 12:15, 13:15 UT) were processed for June 2003. The retrieved optical thicknesses and Angström coefficients are in good agreement with AERONET in-situ measurements in the Atlantic and in the Mediterranean. Monthly mean maps of both parameters are compared to that obtained with the polar orbiting sensor POLDER for June 2003. There is a good consistency between the two monthly means in terms of optical thickness, but the Angström coefficients show significant differences in the Atlantic zone which is affected by dust transport. These differences may be explained by the lack of specific non-spherical dust models within the inversion. The preliminary results presented in this paper demonstrate, nevertheless, the potential of MSG/SEVIRI for the monitoring of aerosol optical properties at high frequencies over the Atlantic and the Mediterranean.

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