Five Years of Dust Episodes at the Southern Italy GAW Regional Coastal Mediterranean Observatory: Multisensors and Modeling Analysis

The Mediterranean area is a climate-change hotspot because of the natural and anthropogenic pollution pressure. The presence of natural aerosols, such as dust, influences solar radiation and contributes to the detection, in storm episodes, of significant concentrations of PM10 in Southern Italy, where generally fresh and clean air is due to local circulation, and particulate matter concentrations are very low. We present the results of medium-term observations (2015–2019) at Lamezia Terme GAW (Global Atmospheric Watch) Regional Observatory, with the purpose of identifying the dust incursion events by studying the aerosol properties in the site. To achieve this goal, the experimental data, collected by several instruments, have been also correlated with the large-scale atmospheric patterns derived by the ERA5 reanalysis dataset, in order to study the meteorological conditions that strongly influence dust outbreaks and their spatio-temporal behavior. An intense dust-outbreak episode, which occurred on 23–27 April 2019, was chosen as a case study; a detailed analysis was carried out considering surface and column optical properties, chemical properties, large-scale pattern circulation, air-quality modeling/satellite products, and back-trajectory analysis, to confirm the capability of the modeled large-scale atmospheric fields to correctly simulate the conditions mainly related to the desert dust-outbreak events.

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Airborne microplastic particles detected in the remote marine atmosphere

Communications Earth & Environment ◽

10.1038/s43247-020-00061-y ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Miri Trainic ◽

J. Michel Flores ◽

Iddo Pinkas ◽

Maria Luiza Pedrotti ◽

Fabien Lombard ◽

...

Keyword(s):

North Atlantic ◽

Trajectory Analysis ◽

North Atlantic Ocean ◽

Anthropogenic Pollution ◽

Terminal Velocity ◽

Back Trajectory ◽

Marine Atmosphere ◽

Local Production ◽

The North ◽

Back Trajectory Analysis

AbstractAnthropogenic pollution from marine microplastic particles is a growing concern, both as a source of toxic compounds, and because they can transport pathogens and other pollutants. Airborne microplastic particles were previously observed over terrestrial and coastal locations, but not in the remote ocean. Here, we collected ambient aerosol samples in the North Atlantic Ocean, including the remote marine atmosphere, during the Tara Pacific expedition in May-June 2016, and chemically characterized them using micro-Raman spectroscopy. We detected a range of airborne microplastics, including polystyrene, polyethylene, polypropylene, and poly-silicone compounds. Polyethylene and polypropylene were also found in seawater, suggesting local production of airborne microplastic particles. Terminal velocity estimations and back trajectory analysis support this conclusion. For technical reasons, only particles larger than 5 µm, at the upper end of a typical marine atmospheric size distribution, were analyzed, suggesting that our analyses underestimate the presence of airborne microplastic particles in the remote marine atmosphere.

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South East Pacific atmospheric composition and variability sampled along 20° S during VOCALS-REx

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-5237-2011 ◽

2011 ◽

Vol 11 (11) ◽

pp. 5237-5262 ◽

Cited By ~ 102

Author(s):

G. Allen ◽

H. Coe ◽

A. Clarke ◽

C. Bretherton ◽

R. Wood ◽

...

Keyword(s):

Boundary Layer ◽

Land Surface ◽

Large Scale ◽

Trajectory Analysis ◽

Model Simulation ◽

Atmospheric Composition ◽

Back Trajectory ◽

Free Troposphere ◽

Back Trajectory Analysis ◽

East Pacific

Abstract. The VAMOS Ocean-Cloud-Atmosphere-Land Regional Experiment (VOCALS-REx) was conducted from 15 October to 15 November 2008 in the South East Pacific (SEP) region to investigate interactions between land, sea and atmosphere in this unique tropical eastern ocean environment and to improve the skill of global and regional models in representing the region. This study synthesises selected aircraft, ship and surface site observations from VOCALS-REx to statistically summarise and characterise the atmospheric composition and variability of the Marine Boundary Layer (MBL) and Free Troposphere (FT) along the 20° S parallel between 70° W and 85° W. Significant zonal gradients in mean MBL sub-micron aerosol particle size and composition, carbon monoxide, sulphur dioxide and ozone were seen over the campaign, with a generally more variable and polluted coastal environment and a less variable, more pristine remote maritime regime. Gradients in aerosol and trace gas concentrations were observed to be associated with strong gradients in cloud droplet number. The FT was often more polluted in terms of trace gases than the MBL in the mean; however increased variability in the FT composition suggests an episodic nature to elevated concentrations. This is consistent with a complex vertical interleaving of airmasses with diverse sources and hence pollutant concentrations as seen by generalised back trajectory analysis, which suggests contributions from both local and long-range sources. Furthermore, back trajectory analysis demonstrates that the observed zonal gradients both in the boundary layer and the free troposphere are characteristic of marked changes in airmass history with distance offshore – coastal boundary layer airmasses having been in recent contact with the local land surface and remote maritime airmasses having resided over ocean for in excess of ten days. Boundary layer composition to the east of 75° W was observed to be dominated by coastal emissions from sources to the west of the Andes, with evidence for diurnal pumping of the Andean boundary layer above the height of the marine capping inversion. Analysis of intra-campaign variability in atmospheric composition was not found to be significantly correlated with observed low-frequency variability in the large scale flow pattern; campaign-average interquartile ranges of CO, SO2 and O3 concentrations at all longitudes were observed to dominate over much smaller differences in median concentrations calculated between periods of different flow regimes. The campaign climatology presented here aims to provide a valuable dataset to inform model simulation and future process studies, particularly in the context of aerosol-cloud interaction and further evaluation of dynamical processes in the SEP region for conditions analogous to those during VOCALS-REx. To this end, our results are discussed in terms of coastal, transitional and remote spatial regimes in the MBL and FT and a gridded dataset are provided as a resource.

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Heavy Precipitation Systems in Calabria Region (Southern Italy): High-Resolution Observed Rainfall and Large-Scale Atmospheric Pattern Analysis

Water ◽

10.3390/w12051468 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1468 ◽

Cited By ~ 4

Author(s):

Aldo Greco ◽

Davide Luciano De Luca ◽

Elenio Avolio

Keyword(s):

High Resolution ◽

Heavy Rainfall ◽

Large Scale ◽

Southern Italy ◽

Early Warning Systems ◽

Reanalysis Dataset ◽

Rainfall Events ◽

Calabria Region ◽

Depth Analysis ◽

Heavy Rainfall Events

An in-depth analysis of historical heavy rainfall fields clearly constitutes an important aspect in many related topics: as examples, mesoscale models for early warning systems and the definition of design event scenarios can be improved, with the consequent upgrading in the prediction of induced phenomena (mainly floods and landslides) into specific areas of interest. With this goal, in this work the authors focused on Calabria region (southern Italy) and classified the main precipitation systems through the analysis of selected heavy rainfall events from high resolution rain gauge network time series. Moreover, the authors investigated the relationships among the selected events and the main synoptic atmospheric patterns derived by the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5 Reanalysis dataset, in order to assess the possible large-scale scenarios which can induce heavy rainfall events in the study area. The obtained results highlighted: (i) the importance of areal reduction factors, rainfall intensities and amounts in order to discriminate the investigated precipitations systems for the study area; (ii) the crucial role played by the position of the averaged low-pressure areas over the Mediterranean for the synoptic systems, and by low-level temperature for the convective systems.

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The Influence of Meteorological Conditions and Atmospheric Circulation Types on PM10 and Visibility in Tel Aviv

Journal of Applied Meteorology ◽

10.1175/jam2232.1 ◽

2005 ◽

Vol 44 (5) ◽

pp. 606-619 ◽

Cited By ~ 65

Author(s):

Uri Dayan ◽

Ilan Levy

Keyword(s):

Particulate Matter ◽

Extreme Values ◽

Meteorological Data ◽

Chemical Properties ◽

Meteorological Conditions ◽

Back Trajectory ◽

Air Masses ◽

Tel Aviv ◽

Back Trajectory Analysis ◽

Synoptic Weather

Abstract A 3-yr dataset (February 2000–November 2002) of 30-min averages for particulates, visibility, and meteorological data were analyzed to examine the dependence of particulate matter of less than 10 μm in diameter (PM10) mass concentrations and visibility in Tel Aviv, Israel, on seasonal meteorological conditions, synoptic weather patterns, and airmass history. The persistent nature of the summer synoptic weather pattern in the east Mediterranean (EM) region yielded the highest mean visibility (35 km) and lowest variability in PM10 concentrations, as compared with the higher variance for the other seasons, and spring in particular. The frequent passage of the “Sharav” cyclones during spring causes natural dust outbreaks with extreme values that result in a much higher PM10 annual mean (57 μg m−3) as compared with other larger cities. The history of the air mass dictating the physical and chemical properties of the particulate matter reaching Israel was assessed by back-trajectory analysis from predetermined transport sectors. The west and central European sectors, representing mostly the summer flow regime of European clean air masses that are advected over the Mediterranean, differ significantly in their reduced PM10 loading and high visual range from the Arabian Peninsula and North African sectors, originating from the surrounding deserts. Because the most frequent direction of air masses reaching the EM is from European origins, Tel Aviv experiences most of the time satisfying visibility conditions. Applying the definition “very good visibility” for visibility exceeding 19 km shows that about 90% of the time these conditions were met for this 3-yr period.

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Fire and forage quality: post-fire regrowth quality and pyric herbivory in subtropical grasslands of Nepal.

10.22541/au.164198472.24482607/v1 ◽

2022 ◽

Author(s):

Shyam Kumar Thapa ◽

Joost de Jong ◽

Anouschka Hof ◽

Naresh Subedi ◽

Laxmi Joshi ◽

...

Keyword(s):

Crude Protein ◽

Large Scale ◽

Forage Quality ◽

Chemical Properties ◽

Grazing Intensity ◽

Mean Value ◽

Burned Areas ◽

Short Period ◽

Pyric Herbivory ◽

Spatio Temporal

Indiscriminate fire is rampant throughout subtropical South and Southeast Asian grasslands. However, very little is known about the role of fire and pyric herbivory on the functioning of highly productive subtropical monsoon grasslands lying within Cwa-climatic region. We collected grass samples from 60 m x 60 m plots and determined vegetation physical and chemical properties at regular 30-day intervals from April to July 2020, starting from 30 days after fire to assess post-fire regrowth forage quality. We counted pellet groups for the same four months from 2 m x 2 m quadrats that were permanently marked with pegs along the diagonal of each 60 m x 60 m plot to estimate grazing intensity to the progression of post-fire regrowth. We observed strong and significant reductions in crude protein (mean value 9.1 to 4.1 [55% decrease]) and phosphorus (mean value 0.2 to 0.11 [45% decrease]) in forage collected during different time intervals i.e., from 30 days to 120 days after fire. Mesofaunal deer utilised the burned areas extensively for a short period, i.e., up to two months after fire when the burned areas contained short grasses with a higher level of crude protein and phosphorus. Grazing intensity of chital (Axis axis) to post-fire regrowth differed significantly over time since fire, with higher intensity of use at 30 days after fire. Grazing intensity of swamp deer (Rucervus duvaucelii) did not differ significantly until 90 days after fire, however, decreased significantly after 90 days since fire. Large-scale indiscriminate single event fires thus may not fulfil nutritional requirements of all species in mesofaunal deer community in these subtropical monsoon grasslands. We recommend for a spatio-temporal manipulation of fire to reinforce grazing feedback and to yield for the longest possible period a reasonably good food supply for the conservation of mesofaunal deer.

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Evidence for ambient dark aqueous SOA formation in the Po Valley, Italy

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-35485-2015 ◽

2015 ◽

Vol 15 (24) ◽

pp. 35485-35521 ◽

Cited By ~ 2

Author(s):

A. P. Sullivan ◽

N. Hodas ◽

B.J. Turpin ◽

K. Skog ◽

F. N. Keutsch ◽

...

Keyword(s):

Gas Phase ◽

Water Uptake ◽

Large Scale ◽

Organic Aerosol ◽

Water Soluble ◽

Water Evaporation ◽

Back Trajectory ◽

Direct Role ◽

Po Valley ◽

Back Trajectory Analysis

Abstract. Laboratory experiments suggest that water-soluble products from the gas-phase oxidation of volatile organic compounds can partition into atmospheric waters where they are further oxidized to form low volatility products, providing an alternative route for oxidation in addition to further oxidation in the gas-phase. These products can remain in the particle phase after water evaporation forming what is termed as aqueous secondary organic aerosol (aqSOA). However, few studies have attempted to observe ambient aqSOA. Therefore, a suite of measurements, including near real-time WSOC (water-soluble organic carbon), inorganic anions/cations, organic acids, and gas-phase glyoxal, were made during the PEGASOS (Pan-European Gas-AeroSols-climate interaction Study) 2012 campaign in the Po Valley, Italy to search for evidence of aqSOA. Our analysis focused on two specific periods: Period A on 19–21 June and Period B on 3–5 July to represent the first and second halves of the study, respectively. The large scale circulation was predominately from the west in both periods. Plus back trajectory analysis suggested all sites sampled similar air masses during both periods allowing for comparison of Periods A and B. The data collected during both periods were divided into times of increasing relative humidity (RH) and decreasing RH with the aim of diminishing the influence of dilution and mixing on SOA concentrations and other measured variables. Evidence for local aqSOA formation was only observed during Period A. When this occurred, there was a correlation of WSOC with organic aerosol (R2 = 0.86), aerosol liquid water (R2 = 0.69), RH (R2 = 0.45), and aerosol nitrate (R2 = 0.71). Additionally, this was only observed during times of increasing RH, which coincided with dark conditions. Comparisons of WSOC with oxygenated organic aerosol (OOA) factors determined from application of positive matrix factorization analysis on the aerosol mass spectrometer observations of the submicron non-refractory organic particle composition suggested that the WSOC in Periods A and B differed (Period A WSOC vs. OOA-2 R2 = 0.85 and OOA-4 R2 = 0.03 whereas Period B WSOC vs. OOA-2 R2 = 0.03 and OOA-4 R2 = 0.64). OOA-2 had a high O/C (oxygen/carbon) ratio of 0.77, providing evidence that aqueous processing was occurring during Period A. Key factors for local aqSOA production during Period A appear to include: air mass stagnation, which allows aqSOA precursors to accumulate in the region; the formation of substantial local particulate nitrate during the overnight hours, which enhances water uptake by the aerosol; and the presence of significant amounts of ammonia, which may contribute to ammonium nitrate formation and subsequent water uptake and/or play a more direct role in the aqSOA chemistry.

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Documentary data and the study of past droughts: a global state of the art

Climate of the Past ◽

10.5194/cp-14-1915-2018 ◽

2018 ◽

Vol 14 (12) ◽

pp. 1915-1960 ◽

Cited By ~ 34

Author(s):

Rudolf Brázdil ◽

Andrea Kiss ◽

Jürg Luterbacher ◽

David J. Nash ◽

Ladislava Řezníčková

Keyword(s):

Large Scale ◽

State Of The Art ◽

Drought Indices ◽

Documentary Evidence ◽

Climatic Trends ◽

Instrumental Observations ◽

Spatio Temporal ◽

Epigraphic Evidence ◽

Administrative Evidence

Abstract. The use of documentary evidence to investigate past climatic trends and events has become a recognised approach in recent decades. This contribution presents the state of the art in its application to droughts. The range of documentary evidence is very wide, including general annals, chronicles, memoirs and diaries kept by missionaries, travellers and those specifically interested in the weather; records kept by administrators tasked with keeping accounts and other financial and economic records; legal-administrative evidence; religious sources; letters; songs; newspapers and journals; pictographic evidence; chronograms; epigraphic evidence; early instrumental observations; society commentaries; and compilations and books. These are available from many parts of the world. This variety of documentary information is evaluated with respect to the reconstruction of hydroclimatic conditions (precipitation, drought frequency and drought indices). Documentary-based drought reconstructions are then addressed in terms of long-term spatio-temporal fluctuations, major drought events, relationships with external forcing and large-scale climate drivers, socio-economic impacts and human responses. Documentary-based drought series are also considered from the viewpoint of spatio-temporal variability for certain continents, and their employment together with hydroclimate reconstructions from other proxies (in particular tree rings) is discussed. Finally, conclusions are drawn, and challenges for the future use of documentary evidence in the study of droughts are presented.

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Short-Term Sustainability of Drainage Water Reuse: Spatio-Temporal Impacts on Soil Chemical Properties

Journal of Environmental Quality ◽

10.2134/jeq2007.0140 ◽

2008 ◽

Vol 37 (S5) ◽

pp. S-8-S-24 ◽

Cited By ~ 18

Author(s):

Dennis L. Corwin ◽

Scott M. Lesch ◽

James D. Oster ◽

Stephen R. Kaffka

Keyword(s):

Water Reuse ◽

Chemical Properties ◽

Drainage Water ◽

Soil Chemical Properties ◽

Short Term ◽

Spatio Temporal ◽

Drainage Water Reuse

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Stratigraphic and Tectonic Setting of the Liguride Units Cropping Out along the Southeastern Side of the Agri Valley (Southern Apennines, Italy)

Geosciences ◽

10.3390/geosciences11030125 ◽

2021 ◽

Vol 11 (3) ◽

pp. 125

Author(s):

Giacomo Prosser ◽

Giuseppe Palladino ◽

Dario Avagliano ◽

Francesco Coraggio ◽

Eleonora Maria Bolla ◽

...

Keyword(s):

Field Survey ◽

Southern Italy ◽

Tectonic Setting ◽

Mediterranean Area ◽

Fold Belt ◽

Southern Apennines ◽

Tectonic Structures ◽

Subsurface Geology ◽

Multidisciplinary Study ◽

Geological Map

This paper shows the main results of a multidisciplinary study performed along the southeastern sector of the Agri Valley in Basilicata (Southern Italy), where Cenozoic units, crucial for constraining the progressive evolution of the Southern Apennine thrust and fold belt and, more in general, the geodynamic evolution of the Mediterranean area are widely exposed. In particular, we aimed at understanding the stratigraphic and tectonic setting of deep-sea, thrust-top Cenozoic units exposed immediately to north of Montemurro, between Costa Molina and Monte dell’Agresto. In the previous works different units, showing similar sedimentological characteristics but uncertain age attribution, have been reported in the study area. In our study, we focussed on the Albidona Formation, pertaining to the Liguride realm, which shows most significant uncertainties regarding the age and the stratigraphic setting. The study was based on a detailed field survey which led to a new geological map of the area. This was supported by new stratigraphic, biostratigraphic and structural analyses. Biostratigraphic analysis provided an age not older than the upper Ypresian and not younger than the early Priabonian. Recognition of marker stratigraphic horizons strongly helped in the understanding of the stratigraphy of the area. The study allowed a complete revision of the stratigraphy of the outcropping Cenozoic units, the recognition of until now unknown tectonic structures and the correlation between surface and subsurface geology.

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Establishment and lineage dynamics of the SARS-CoV-2 epidemic in the UK

Science ◽

10.1126/science.abf2946 ◽

2021 ◽

pp. eabf2946

Author(s):

Louis du Plessis ◽

John T. McCrone ◽

Alexander E. Zarebski ◽

Verity Hill ◽

Christopher Ruis ◽

...

Keyword(s):

Large Scale ◽

Phylogenetic Analyses ◽

Transmission Dynamics ◽

Genetic Lineage ◽

Size Dependent ◽

Spatio Temporal ◽

The Uk ◽

Lineage Structure ◽

And Control ◽

Lineage Diversity

The UK’s COVID-19 epidemic during early 2020 was one of world’s largest and unusually well represented by virus genomic sampling. Here we reveal the fine-scale genetic lineage structure of this epidemic through analysis of 50,887 SARS-CoV-2 genomes, including 26,181 from the UK sampled throughout the country’s first wave of infection. Using large-scale phylogenetic analyses, combined with epidemiological and travel data, we quantify the size, spatio-temporal origins and persistence of genetically-distinct UK transmission lineages. Rapid fluctuations in virus importation rates resulted in >1000 lineages; those introduced prior to national lockdown tended to be larger and more dispersed. Lineage importation and regional lineage diversity declined after lockdown, while lineage elimination was size-dependent. We discuss the implications of our genetic perspective on transmission dynamics for COVID-19 epidemiology and control.

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