scholarly journals Oxidation processes in the Eastern Mediterranean atmosphere: Evidence from the Modelling of HO<sub>x</sub> Measurements over Cyprus

2018 ◽  
Author(s):  
Chinmay Mallik ◽  
Laura Tomsche ◽  
Efstratios Bourtsoukidis ◽  
John N. Crowley ◽  
Bettina Derstroff ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Air Masses ◽  
North West ◽  
Sources And Sinks ◽  
Oxidation Processes ◽  
The North ◽  
Range Transport ◽  
The Mediterranean ◽  
Marine Air ◽  
Measurement Location

Abstract. The Mediterranean is a climatically sensitive region located at the crossroads of air masses from three continents: Europe, Africa and Asia. The chemical processing of air masses over this region has implications not only for the air quality, but also for the long-range transport of air pollution. To obtain a comprehensive understanding of oxidation processes over the Mediterranean, atmospheric concentrations of the hydroxyl radical (OH) and the hydroperoxyl radical (HO2) were measured during an intensive field campaign (CYprus PHotochemistry EXperiment, CYPHEX-2014) in the north-west of Cyprus in the summer of 2014. Very low local anthropogenic and biogenic emissions around the measurement location provided a vantage point to study the contrasts in atmospheric oxidation pathways under highly processed marine air masses and those influenced by relatively fresh emissions from mainland Europe. The CYPHEX measurements were used to evaluate OH and HO2 simulations using a photochemical box model (CAABA/MECCA) constrained with CYPHEX observations of O3, CO, NOx, hydrocarbons, peroxides and other major HOx (OH + HO2) sources and sinks in a low NOx environment (

scholarly journals Oxidation processes in the eastern Mediterranean atmosphere: evidence from the modelling of HO<sub><i>x</i></sub> measurements over Cyprus

2018 ◽  
Vol 18 (14) ◽  
pp. 10825-10847 ◽  
Author(s):  
Chinmay Mallik ◽  
Laura Tomsche ◽  
Efstratios Bourtsoukidis ◽  
John N. Crowley ◽  
Bettina Derstroff ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Early Morning ◽  
Rate Coefficients ◽  
Peroxy Radicals ◽  
Air Masses ◽  
Model Simulations ◽  
Oxidation Processes ◽  
The Mediterranean ◽  
Marine Air

Abstract. The Mediterranean is a climatically sensitive region located at the crossroads of air masses from three continents: Europe, Africa, and Asia. The chemical processing of air masses over this region has implications not only for the air quality but also for the long-range transport of air pollution. To obtain a comprehensive understanding of oxidation processes over the Mediterranean, atmospheric concentrations of the hydroxyl radical (OH) and the hydroperoxyl radical (HO2) were measured during an intensive field campaign (CYprus PHotochemistry EXperiment, CYPHEX-2014) in the northwest of Cyprus in the summer of 2014. Very low local anthropogenic and biogenic emissions around the measurement location provided a vantage point to study the contrasts in atmospheric oxidation pathways under highly processed marine air masses and those influenced by relatively fresh emissions from mainland Europe.The CYPHEX measurements were used to evaluate OH and HO2 simulations using a photochemical box model (CAABA/MECCA) constrained with CYPHEX observations of O3, CO, NOx, hydrocarbons, peroxides, and other major HOx (OH + HO2) sources and sinks in a low-NOx environment (< 100 pptv of NO). The model simulations for OH agreed to within 10 % with in situ OH observations. Model simulations for HO2 agreed to within 17 % of the in situ observations. However, the model strongly under-predicted HO2 at high terpene concentrations, this under-prediction reaching up to 38 % at the highest terpene levels. Different schemes to improve the agreement between observed and modelled HO2, including changing the rate coefficients for the reactions of terpene-generated peroxy radicals (RO2) with NO and HO2 as well as the autoxidation of terpene-generated RO2 species, are explored in this work. The main source of OH in Cyprus was its primary production from O3 photolysis during the day and HONO photolysis during early morning. Recycling contributed about one-third of the total OH production, and the maximum recycling efficiency was about 0.7. CO, which was the largest OH sink, was also the largest HO2 source. The lowest HOx production and losses occurred when the air masses had higher residence time over the oceans.

Distribution of Jet Streams at 200 mb. in the Middle East

1967 ◽  
Vol 20 (4) ◽  
pp. 397-404
Author(s):  
A. F. Crossley ◽  
I. N. Parkinson
Keyword(s):  
Middle East ◽  
North Atlantic ◽  
Eastern Mediterranean ◽  
Jet Streams ◽  
North West ◽  
The North ◽  
European Area ◽  
The North Atlantic ◽  
The Mediterranean ◽  
The Persian Gulf

1. INTRODUCTION. The distribution of jet streams over the North Atlantic, Europe and the Mediterranean for the two years 1957–8 was described in an earlier paper (Crossley, 1961); the present paper extends the study to the area which is here referred to somewhat loosely as the Middle East —it extends between latitudes 40° N. and 10;° N., and from longitude 30° E. to 90° E. in the north but to only 65° E. in the south (Fig. 1). The aircraft trunk routes intersecting this area include those from the Eastern Mediterranean across Arabia and the Persian Gulf to West Pakistan and north-west India.The jet streams which affect the Atlantic-European area in the upper troposphere are mostly of the ‘polar’ type with a core in the neighbourhood of 300 mb. so that they can be conveniently located as a rule on the contour charts for 300 mb.; in the Mediterranean region and in the corresponding latitudes of the North Atlantic the westerly subtropical jet stream is also concerned and charts for both 300 and 200 mb.

scholarly journals New Data on the Biology and Fisheries of the Threatened Palinurus elephas (Fabricius, 1787) (Decapoda, Achelata, Palinuridae) from the North-West Aegean Sea, Greece

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2390
Author(s):  
Thodoros E. Kampouris ◽  
Drosos Koutsoubas ◽  
Debora Milenkova ◽  
Georgios Economidis ◽  
Stylianos Tamvakidis ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Eastern Mediterranean ◽  
Spiny Lobster ◽  
Aegean Sea ◽  
North West ◽  
The North ◽  
Coastal Species ◽  
The Mediterranean ◽  
Species Specific ◽  
Palinurus Elephas

The European spiny lobster Palinurus elephas is a vulnerable species that inhabits and is harvested in the Mediterranean Sea and the adjacent Atlantic waters. The fisheries associated with the spiny lobster are mainly conducted with tangle nets, trammel nets, pots, and creels. The fishing pressure has greatly reduced their numbers, changing them from a common shallow coastal species to a largely remnant population. The relative research on the species’ biology and fisheries from the eastern Mediterranean Sea is almost absent. The fishery along the Chalkidiki Peninsula, Greece, is multispecies, and fishing is conducted by a small number of artisanal fishermen mainly using trammel nets. The lobster stock—both spiny and clawed lobsters—declined significantly during the late 1980s and early 1990s, later than most cases in the Mediterranean Sea. However, data regarding the nature and status of the fishery associated with the spiny lobster in Greece are lacking. Data regarding the characteristics of the spiny regional fishery were obtained by interviews and questionnaires. Additionally, fishery surveys were conducted during the main lobster fishing season from 1 May 2017 to 31 August 2017. Sixteen species were identified (15 finfish species and one invertebrate species) as targeted. In total, 79 spiny lobsters were sampled in this study; the population’s sex ratio significantly diverts from the theoretical 1:1 (χ2 = 4.57; p < 0.05), and males were dominant. Both male and female individuals demonstrate negative allometric growth profiles. In addition, no significant differences were observed between sexes. In Greece, thus far, the knowledge and information are sporadic, limited, and/or species-specific, most of which regard finfish fisheries. Furthermore, the national legislation is rather complicated—or too generalized—thus creating great uncertainties. The in-depth knowledge and experience of fishermen should be further acknowledged and utilized, and wider collaborations among scientists, practitioners, and policy-makers should be established. The present study poses some thoughts on the effectiveness of the recent EU Landing Obligation and its contribution to the potential restoration of the species.

scholarly journals Genetic flow among olive populations within the Mediterranean basin

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5260 ◽  
Author(s):  
Valentina di Rienzo ◽  
Sara Sion ◽  
Francesca Taranto ◽  
Nunzio D’Agostino ◽  
Cinzia Montemurro ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Olive Tree ◽  
Gene Pools ◽  
The North ◽  
The Mediterranean ◽  
And Migration ◽  
The Mediterranean Basin

Background The olive tree is a typical crop of the Mediterranean basin where it shows a wide diversity, accounting for more than 2,600 cultivars. The ability to discriminate olive cultivars and determine their genetic variability is pivotal for an optimal exploitation of olive genetic resources. Methods We investigated the genetic diversity within 128 olive accessions belonging to four countries in the Mediterranean Basin (Italy, Algeria, Syria, and Malta), with the purpose of better understanding the origin and spread of the olive genotypes across Mediterranean Basin countries. Eleven highly polymorphic simple sequence repeat (SSR) markers were used and proved to be very informative, producing a total of 179 alleles. Results Cluster analysis distinguished three main groups according to their geographical origin, with the current sample of Maltese accessions included in the Italian group. Phylogenetic analysis further differentiated Italian and Maltese olive accessions, clarifying the intermediate position of Maltese accessions along the x/y-axes of principal coordinate analysis (PCoA). Model-based and neighbor clustering, PCoA, and migration analysis suggested the existence of two different gene pools (Algerian and Syrian) and that the genetic exchange occurred between the Syrian, Italian and Maltese populations. Discussion The close relationship between Syrian and Italian and Maltese olives was consistent with the historical domestication and migration of olive tree from the North Levant to eastern Mediterranean basin. This study lays the foundations for a better understanding of olive genetic diversity in the Mediterranean basin and represents a step toward an optimal conservation and exploitation of olive genetic resources.

Challenges and opportunities extending the INTIMATE tephra event stratigraphy into the Levant and Arabia.

2020 ◽  
Author(s):  
Simon Blockley ◽  
Dustin White ◽  
Rhys Timms ◽  
Paul Lincoln ◽  
Simon Armitage ◽  
...  
Keyword(s):  
North Atlantic ◽  
Eastern Mediterranean ◽  
Ice Core ◽  
Limited Range ◽  
Geochemical Data ◽  
Interglacial Period ◽  
The North ◽  
Event Stratigraphy ◽  
The North Atlantic ◽  
The Mediterranean

&lt;p&gt;The nature and expression of climate change in the Eastern Mediterranean, the Levant and further into Arabia is of considerable interest across a range of communities. This is in part due to the need to understand the potential for future climate forcing on environments given the complex range of climatic forcing factors that play out in the region. These include the role of prevailing winds across the Mediterranean, Northerly winds pushing down into the region during cold glacial conditions, and the influence of the Afro-Arabian Monsoon. The last glacial to interglacial period is a critical window to examine such processes, as a range of climatic signals are recorded, many of which have been proposed as correlatives of events seen in the North Atlantic. Dating issues are as ever an issue when trying to precisely compare different climate archives. To address such, the INTIMATE event stratigraphy has been developed for the North Atlantic region, with recent extensions into parts of the Mediterranean. This couples the stratigraphic framework of the Greenland Ice core records as a regional stratotype, with &amp;#160;a number of tephra horizons in the North Atlantic and Europe, aiding the process of correlation. The last INTIMATE event stratigraphy coupled the extended GICC05 timescale for Greenland back to 128 b2k (Blockley et al., 2014). This paper reports on attempts to test the potential for tephrochronology to be extended into the Levant and potentially Arabia, through the identification of tephra layers in sediment focussing archives, such as archaeological cave sequences. We have examined tephra presence in archaeological sites, principally in Israel, that record sediment deposition from ~30ka BP through to &gt;100ka BP. Analyses of these records show that tephra is present in almost all of the studied sites (e.g., Kebara, Tabun, Amud, Shovakh). Moreover, tephra in these sequences can be chemically correlated to known volcanic systems, demonstrating the potential going forward to analyse long lake and marine records around the region for cryptotephra. At the same time clear challenges are emerging. Firstly, there is a range of chemistry in many of the layers and careful analyses is needed to pick apart the geochemical signal and to identify reworking, as opposed to chemically heterogeneous ash layers from a single volcano. This process is complicated by the relatively limited range of published geochemical data from some volcanic centres. This presentation will outline the current state of knowledge of key volcanic centres, particularly in the Aegean and Turkey, alongside the new Levantine data, to consider the steps needed to establish a secure extension of the INTIMATE approach into this region.&lt;/p&gt;&lt;p&gt;Blockley, S., et al., 2014. Quaternary Science Reviews. 106, 88-100. doi:10.1016/j.quascirev.2014.11.002.&lt;/p&gt;

scholarly journals New Fisheries-related data from the Mediterranean Sea (April 2014)

2014 ◽  
Vol 15 (1) ◽  
pp. 213 ◽  
Author(s):  
K. STERGIOU ◽  
D.C. BOBORI ◽  
F.G. EKMEKÇİ ◽  
M. GÖKOĞLU ◽  
P.K. KARACHLE ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Eastern Mediterranean ◽  
Feeding Habits ◽  
Aegean Sea ◽  
Northern Greece ◽  
Related Data ◽  
The North ◽  
North Aegean ◽  
The Mediterranean ◽  
North Aegean Sea

As part of its policy, Mediterranean Marine Science started from 2014 to publish a new series of collective article with fisheries-related data from the Mediterranean Sea. In this first collective article we present length frequencies and weight-length relationships for the northern brown shrimp Farfantepenaeus aztecus in the eastern Mediterranean, length-weight relationships for 10 fish species in the North Aegean Sea, the feeding habits for 11 sparid fishes in the North Aegean Sea, a review of the existing literature on the feeding and reproduction of common carp Cyprinus carpio in Anatolia (Turkey) and mouth dimensions and the relationships between mouth area and length for seven freshwater fishes from Lake Volvi (Northern Greece).

scholarly journals Atmospheric mercury in the Southern Hemisphere – Part 2: Source apportionment analysis at Cape Point station, South Africa

2020 ◽  
Author(s):  
Johannes Bieser ◽  
Hélène Angot ◽  
Franz Slemr ◽  
Lynwill Martin
Keyword(s):  
South Africa ◽  
Southern Hemisphere ◽  
Source Region ◽  
Global Scale ◽  
Atmospheric Mercury ◽  
Air Masses ◽  
Sources And Sinks ◽  
Relative Contribution ◽  
Range Transport ◽  
Significant Step

Abstract. Mercury (Hg) contamination is ubiquitous. In order to assess its emissions, transport, atmospheric reactivity, and deposition pathways, Hg monitoring stations have been implemented on a global scale over the past 10–20 years. Despite this significant step forward, the monitoring efforts have been insufficient to fulfill our understanding of Hg cycling in the Southern Hemisphere. While oceans make up 80 % of the Southern Hemisphere's surface area, little is known about the effects of oceans on Hg cycling in this region. For instance, in the context of growing interest in effectiveness evaluation of Hg mitigation policies, the relative contribution of anthropogenic and legacy emissions to present-day atmospheric Hg levels is unclear. This paper constitutes Part 2 of the study describing a decade of atmospheric Hg concentrations at Cape Point, South Africa, i.e. the first long-term (> 10 years) observations in the Southern Hemisphere. Building on the trend analysis reported in Part 1, here we combine atmospheric Hg data with a trajectory model to investigate sources and sinks of Hg at Cape Point. We find that the continent is the major sink and the Ocean, especially warm regions, is the major source for Hg. Further, we find that mercury concentrations and trends from long range transport are independent of the source region (e.g. South America, Antarctica) and thus indistinguishable. Therefor, by filtering out air masses from source and sink regions we are able to create a dataset representing a southern hemispheric background Hg concentrations. Based on this dataset we were able to show that the inter-annual variability of Hg concentrations is not driven by changes in atmospheric circulation but rather due to changes in global emissions (gold mining and biomass burning).

scholarly journals The GLAM Airborne Campaign across the Mediterranean Basin

2018 ◽  
Vol 99 (2) ◽  
pp. 361-380 ◽  
Author(s):  
Philippe Ricaud ◽  
Régina Zbinden ◽  
Valéry Catoire ◽  
Vanessa Brocchi ◽  
François Dulac ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Chemical Mapping ◽  
Air Masses ◽  
Airborne Measurements ◽  
The Mediterranean ◽  
The Impact ◽  
The Mediterranean Basin

Abstract The Gradient in Longitude of Atmospheric Constituents above the Mediterranean Basin (GLAM) airborne campaign was set up to investigate the summertime variability of gaseous pollutants, greenhouse gases, and aerosols between the western (∼3°E) and eastern (∼35°E) sections of the Mediterranean basin as well as how this connects with the impact of the Asian monsoon anticyclone on the eastern Mediterranean in the mid- to upper troposphere (∼5–10 km). GLAM falls within the framework of the Chemistry–Aerosol Mediterranean Experiment (ChArMEx) program. GLAM used the French Falcon-20 research aircraft to measure aerosols, humidity, and chemical compounds: ozone, carbon monoxide, methane, and carbon dioxide. GLAM took place between 6 and 10 August 2014, following a route from Toulouse (France) to Larnaca (Cyprus) and back again via Minorca (Spain), Lampedusa (Italy), and Heraklion (Crete, Greece). The aircraft flew at an altitude of 5 km on its outbound journey and 10 km on the return leg. GLAM also collected vertical profiles around the landing sites listed above. A combination of model outputs, chemical mapping analyses, and spaceborne and surface station measurements gathered prior to and during the campaign were used to interpret the in situ airborne measurements. The main outcome of this study is the impact of intercontinental transport on the longitudinal variability of pollutants, greenhouse gases, and aerosols at an altitude of 10 km. The eastern Mediterranean is affected by air masses from the Arabian Sea surface, and the western Mediterranean is impacted by air masses from North America (biomass burning) and West Africa (desert dust).

The ‘Hearth of Domestication’? Transitions to Farming in South-West Asia

2006 ◽  
Author(s):  
Graeme Barker
Keyword(s):  
Persian Gulf ◽  
Mediterranean Coast ◽  
North West ◽  
Hill Country ◽  
Anatolian Plateau ◽  
The North ◽  
South West ◽  
The Mediterranean ◽  
Western Side ◽  
The Persian Gulf

The principal focus of this chapter is the classic zone of early farming research from the 1960s onwards, the so-called ‘hilly flanks of the Fertile Crescent’ in South-West Asia (Fig. 4.1). This region is normally defined as the arc of hill country to the west of the Syrian desert and to the north and east of the Tigris and Euphrates valleys. The western side of the arc begins east of the Nile in the Sinai and the Gulf of Arabah on the southern border of Israel and Jordan; it continues northwards as the hill country on either side of the Jordan rift valley in Israel, Palestine, Lebanon, western Jordan, and western Syria (the so-called ‘Levantine corridor’); and extends westwards to the Mediterranean littoral. The northern sector is formed by the Taurus mountains along the southern edge of the Anatolian plateau, which curve eastwards from the Mediterranean coast in northern Syria to form the present-day Syrian–Turkish border. The eastern sector consists of the Zagros mountains, running south-eastwards from eastern Turkey and north-west Iran to the Persian Gulf, forming the Iraq–Iran border for most of their length, and continuing in south-west Iran beyond the Persian Gulf towards the Straits of Hormuz. The region also embraces adjacent zones: the alluvial plains of the Tigris and Euphrates rivers and the vast tracts of steppe and desert country separating them from the Levantine, Taurus, and Zagros upland systems; the Anatolian plateau to the north of the Taurus, within modern Turkey; and the Iranian plateau east of the Zagros, within modern Iran. The archaeological literature commonly uses the term Near East to describe the main region of interest, with the Levant for its western side (a term also used in this chapter), and South-West Asia for the eastern side, but the entire region is more correctly termed South-West Asia. The upland areas of the region mostly receive more than 200 millimetres of rainfall a year, which is the minimum required for growing cereals without irrigation. Rainfall decreases drastically moving out into the steppe and desert zones.

The Climate System

2009 ◽  
Author(s):  
Andrew Harding ◽  
Jean Palutikof
Keyword(s):  
High Pressure ◽  
Mediterranean Region ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Subtropical High ◽  
Westerly Wind ◽  
The West ◽  
The North ◽  
Dry Conditions ◽  
The Mediterranean

The Mediterranean region has a highly distinctive climate due to its position between 30 and 45°N to the west of the Euro-Asian landmass. With respect to the global atmospheric system, it lies between subtropical high pressure systems to the south, and westerly wind belts to the north. In winter, as these systems move equatorward, the Mediterranean basin lies under the influence of, and is exposed to, the westerly wind belt, and the weather is wet and mild. In the summer, as shown in Figure 3.1, the Mediterranean lies under subtropical high pressure systems, and conditions are hot and dry, with an absolute drought that may persist for more than two or three months in drier regions. Climates such as this are relatively rare, and the Mediterranean shares its winter wet/summer dry conditions with locations as distant as central Chile, the southern tip of Cape Province in South Africa, southwest Australia in the Southern Hemisphere, and central California in the Northern Hemisphere. All have in common their mid-latitude position, between subtropical high pressure systems and westerly wind belts. They all lie on the westerly side of continents so that, in winter, when the westerly wind belts dominate over their locations, they are exposed to rain-bearing winds. In the Köppen classification (Köppen 1936), these climates are known as Mediterranean (Type Cs, which is subdivided in turn into maritime Csb and continental Csa). The influence of the Mediterranean Sea means that the Mediterranean-type climate of the region extends much further into the continental landmass than elsewhere, and is not restricted to a narrow ocean-facing strip. Nevertheless, within the Mediterranean region climate is modified by position and topographic influences can be important. The proximity of the western Mediterranean to the Atlantic Ocean gives its climate a maritime flavour, with higher rainfall and milder temperatures throughout the year. The eastern Mediterranean lies closer to the truly continental influences of central Europe and Asia. Its climate is drier, and temperatures are hotter in summer and colder in winter than in the west. Annual rainfall is typically around 750 mm in Rome, but only around 400 mm in Athens.

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