scholarly journals Size resolved mass concentration and elemental composition of atmospheric aerosols over the eastern Mediterranean area

2003 ◽  
Vol 3 (3) ◽  
pp. 2547-2573 ◽  
Author(s):  
J. Smolik ◽  
V. Ždimal ◽  
J. Schwarz ◽  
M. Lazaridis ◽  
V. Havránek ◽  
...  

Abstract. A Berner low pressure impactor was used to collect size-segregated aerosol samples at Finokalia, located on the north-eastern coast of Crete, Greece during July 2000 and January 2001. Several samples were also collected during the summer campaign aboard the research vessel "AEGAIEO" in the Aegean Sea. Gravimetric analysis and inversion techniques yielded daily PM1 and PM10 mass concentrations. Further, the samples were analysed by PIXE giving elemental size distributions of Al, Si, K, Ca, Ti, Mn, Fe, Sr, S, Cl, Ni, V, Cu, Cr, Zn, and Pb. The crustal elements and sea-salt had a unimodal supermicron size distribution. Sulphur was found predominantly in submicron fractions. K, V, and Ni exhibited bimodal distribution with a submicron mode produced by forest fires and oil combustion. The anthropogenic elements had broad and not well-defined distributions. The time series for PM1 and PM10 mass and elemental concentrations showed both daily and seasonal variation. Higher mass concentrations were observed during two incursions of Saharan dust. Higher concentrations of S, Cu, Zn, and Pb were encountered in samples collected in air masses arriving from northern Greece or the western coast of Turkey. Higher concentrations of chlorine were found in samples with air masses either originating above the Atlantic Ocean and arriving at Finokalia via western Europe or recirculating over the western coast of the Black Sea.

2003 ◽  
Vol 3 (6) ◽  
pp. 2207-2216 ◽  
Author(s):  
J. Smolík ◽  
V. Ždímal ◽  
J. Schwarz ◽  
M. Lazaridis ◽  
V. Havárnek ◽  
...  

Abstract. A Berner low pressure impactor was used to collect size-segregated aerosol samples at Finokalia, located on the north-eastern coast of Crete, Greece during July 2000 and January 2001. Several samples were also collected during the summer campaign aboard the research vessel "AEGAIEO" in the Aegean Sea. Gravimetric analysis and inversion techniques yielded daily PM1 and PM10 mass concentrations. The samples were also analysed by PIXE giving the elemental size distributions of Al, Si, K, Ca, Ti, Mn, Fe, Sr, S, Cl, Ni, V, Cu, Cr, Zn, and Pb. The crustal elements and sea-salt had a unimodal supermicron size distribution. Sulphur was found predominantly in submicron fractions. K, V, and Ni exhibited a bimodal distribution with a submicron mode produced by forest fires and oil combustion. The anthropogenic elements had broad and not well-defined distributions. The time series for PM1 and PM10 mass and elemental concentrations showed both daily and seasonal variation. Higher mass concentrations were observed during two incursions of Saharan dust, whilst higher concentrations of S, Cu, Zn, and Pb were encountered in samples collected in air masses arriving from northern Greece or the western coast of Turkey. Elevated concentrations of chlorine were found in samples with air masses either originating above the Atlantic Ocean and arriving at Finokalia via western Europe or recirculating over the western coast of the Black Sea.


2012 ◽  
Vol 5 (2) ◽  
pp. 321-327 ◽  
Author(s):  
F. Conen ◽  
S. Henne ◽  
C. E. Morris ◽  
C. Alewell

Abstract. Small number concentrations render it difficult to quantify ice nucleators (IN) in the atmosphere active at warm temperatures. A useful new method for IN measurement based around filter collections is proposed. It makes use of quartz filters used in 24 h PM10 monitoring (720 m3 air sample). Small subsamples (1.8 mm diameter) from the effective filter area and from the clean fringe (blank) are subjected to immersion freezing tests. We applied the method to eight filters from the High Alpine Research Station Jungfraujoch (3580 m above sea level) in the Swiss Alps. All filters carried IN active at −7 °C and below. Number concentrations of IN active at −8, −10, and −12 °C were on average 3.3, 10.7, and 17.2 m−3, respectively. Several-fold larger numbers of IN active at ≥ −12 °C per unit mass of PM10 were found in air masses influenced by Swiss and southern German atmospheric boundary layer air, compared to a Saharan dust event. In combination with data on PM10 mass, the method may be used to re-construct time series of IN number concentrations.


Author(s):  
Erkan Yılmaz ◽  
Yılmaz Akdi ◽  
Esra Uğurca ◽  
İhsan Çiçek ◽  
Cemal Atakan

AbstractTurkey is located in the temperate zone; thus, it is influenced by regionally different air masses during summers and winters, resulting in different precipitation regimes. Often, systems with varying masses of air repeatedly affect Turkey; however, at times, these periods are disrupted and difficult to predict. This study analyzes whether a certain periodicity exists in the seasonal and annual total precipitation of 74 meteorological stations in Turkey using periodograms. The analyses conducted herein showed more than one period in the series; therefore, this study was extended, and the first six periods were examined. As a result, we found 2-, 3-, 4-, and 5-year precipitation cycles (PCs) in the short term; 6-, 7-, and 8-year PCs in the medium term; and 11-, 12-, 14-, 17-, and 21-year PCs in the long term in Turkey’s PC. While seasonal distributions exhibited similarities, there were significant differences in the seasonal frequencies owing to seasonal variations in the systems affecting Turkey. The cycles vary by region, and some of these cycles can be found in each region. Three cycles have been identified in Turkey according to frequency and length, namely: (1) short-term cycle across Turkey; (2) Eastern and Central Anatolia, the Black Sea, and Aegean regions; and (3) borders of Central Anatolian and the eastern Mediterranean region. A cluster identifies unrelated locations as the affected local factors. Cycles are connected to the NAO, whereas solar activity is observed throughout Turkey. The analysis showed that certain cycles were repeated and were not dominant in each period, with the best example of this cycle as the 7–14–21 consecutive cycles.


2020 ◽  
pp. 50-73
Author(s):  
Duane W. Roller

Mithridates II was succeeded by his ephemeral son, Mithridates III, and then by 220 BC his son, Pharnakes I, was on the throne. He was a powerful and aggressive monarch who ruled for over thirty years and greatly expanded the territorial extent of the kingdom. He lived in an era of great change in the Hellenistic world, as the Romans began to become involved in the destinies of the eastern Mediterranean states: Pharnakes reached out to the Romans in the 180s BC concerning territorial disputes in Asia Minor. He engaged in war with his powerful neighbor to the west, Pergamon, but was forced to sign a peace treaty not to his advantage. Yet he expanded Pontic territory along the Black Sea coast and made several alliances with the Greek cities on the northern and western coast of the sea, especially in the kingdom of Bosporos (modern Crimea).


2001 ◽  
Vol 2 (2) ◽  
pp. 33 ◽  
Author(s):  
M. UNSAL

Lead pollution and its sources have been investigated in the south-eastern and south-western Black Sea. Surficial sediments and mussels were collected in different seasons of the year from the south-eastern and south-western Black Sea and analysed for their lead contents.In the south-eastern Black Sea sediments from the easternmost and from the central stations contained the highest lead concentrations. Sediments contained 8 to 10 times the lead concentrations of sediments from the south-west. Samples taken from rivers, streams and effluents had especially high lead concentrations. The highest lead concentrations were found in sediments collected in October and December.Lead concentrations in mussels from the south-eastern coast were comparatively lower compared to those from the south-western coast. The highest average values occurred in December and in October.In the south-western Black Sea, the highest lead concentrations in sediments were obtained in those from Inebolu, followed by those from around Zonguldak. The concentrations increased from the middle to the west of the southern Black Sea coast, possibly due to the effect of the Danube River. Sediments taken in September had the highest lead concentrations, followed by samples taken in December.Very high lead concentrations (> 10 μ g g-1) were observed in mussels from those stations where the sediments also contained high concentrations. Mussels had their highest lead concentrations in January and April.


2006 ◽  
Vol 40 (25) ◽  
pp. 4679-4690 ◽  
Author(s):  
E GERASOPOULOS ◽  
G KOUVARAKIS ◽  
P BABASAKALIS ◽  
M VREKOUSSIS ◽  
J PUTAUD ◽  
...  

2020 ◽  
Vol 324 (2) ◽  
pp. 262-272
Author(s):  
I.V. Doronin ◽  
T.N. Dujsebayeva ◽  
K.M. Akhmedenov ◽  
A.G. Bakiev ◽  
K.N. Plakhov

The article specifies the type locality of the Steppe Ribbon Racer. The holotype Coluber (Taphrometopon) lineolatus Brandt, 1838 is stored in the reptile collection of the Zoological Institute of the Russian Academy of Sciences (ZISP No 2042). Literature sources provide different information about the type locality. A mistake has been made in the title of the work with the original species description: the western coast of the sea was indicated instead of the eastern one. The place of capture was indicated as “M. Caspium” (Caspian Sea) on the label and in the reptile inventory book of the Zoological Museum of the Academy of Sciences. The specimen was sent to the museum by G.S. Karelin. The “1842” indicated on the labels and in the inventory book cannot be the year of capture of the type specimen, just as the “1837” indicated by A.M. Nikolsky. In 1837, Karelin was in Saint Petersburg and in 1842 in Siberia. Most likely, 1837 is the year when the collection arrived at the Museum, and 1842 is the year when the information about the specimen was recorded in the inventory book (catalog) of the Zoological Museum of the Academy of Sciences. In our opinion, the holotype was caught in 1932. From Karelin’s travel notes of the expedition to the Caspian Sea in 1832, follows that the snake was recorded in two regions adjacent to the eastern coast of the Caspian Sea – Ungoza Mountain (“Mangyshlak Mountains”) and site of the Western Chink of Ustyurt between Zhamanairakty and Kyzyltas Mountains (inclusive) on the northeast coast of Kaydak Sor (“Misty Mountains”). In our article, Karelin’s route to the northeastern coast of the Caspian Sea in 1832 and photographs of these localities are given. The type locality of Psammophis lineolatus (Brandt, 1838) should be restricted to the Mangystau Region of the Kazakhstan: Ungoza Mountain south of Sarytash Gulf, Mangystau (Mangyshlak) Penninsula (44°26´ N, 51°12´ E).


Author(s):  
Alba Rey-Iglesia ◽  
Philippe Gaubert ◽  
Gonçalo Espregueira Themudo ◽  
Rosa Pires ◽  
Constanza De La Fuente ◽  
...  

Abstract The Mediterranean monk seal Monachus monachus is one of the most threatened marine mammals, with only 600–700 individuals restricted to three populations off the coast of Western Sahara and Madeira (North Atlantic) and between Greece and Turkey (eastern Mediterranean). Its original range was from the Black Sea (eastern Mediterranean) to Gambia (western African coast), but was drastically reduced by commercial hunting and human persecution since the early stages of marine exploitation. We here analyse 42 mitogenomes of Mediterranean monk seals, from across their present and historical geographic ranges to assess the species population dynamics over time. Our data show a decrease in genetic diversity in the last 200 years. Extant individuals presented an almost four-fold reduction in genetic diversity when compared to historical specimens. We also detect, for the first time, a clear segregation between the two North Atlantic populations, Madeira and Cabo Blanco, regardless of their geographical proximity. Moreover, we show the presence of historical gene-flow between the two water basins, the Atlantic Ocean and the Mediterranean Sea, and the presence of at least one extinct maternal lineage in the Mediterranean. Our work demonstrates the advantages of using full mitogenomes in phylogeographic and conservation genomic studies of threatened species.


2019 ◽  
Vol 19 (6) ◽  
pp. 3557-3578 ◽  
Author(s):  
Martin Osborne ◽  
Florent F. Malavelle ◽  
Mariana Adam ◽  
Joelle Buxmann ◽  
Jaqueline Sugier ◽  
...  

Abstract. On 15–16 October 2017, ex-hurricane Ophelia passed to the west of the British Isles, bringing dust from the Sahara and smoke from Portuguese forest fires that was observable to the naked eye and reported in the UK's national press. We report here detailed observations of this event using the UK operational lidar and sun-photometer network, established for the early detection of aviation hazards, including volcanic ash. We also use ECMWF ERA5 wind field data and MODIS imagery to examine the aerosol transport. The observations, taken continuously over a period of 30 h, show a complex picture, dominated by several different aerosol layers at different times and clearly correlated with the passage of different air masses associated with the intense cyclonic system. A similar evolution was observed at several sites, with a time delay between them explained by their different location with respect to the storm and associated meteorological features. The event commenced with a shallow dust layer at 1–2 km in altitude and culminated in a deep and complex structure that lasted ∼12 h at each site over the UK, correlated with the storm's warm sector. For most of the time, the aerosol detected was dominated by mineral dust mixtures, as highlighted by depolarisation measurements, but an intense biomass burning aerosol (BBA) layer was observed towards the end of the event, lasting around 3 h at each site. The aerosol optical depth at 355 nm (AOD355) during the whole event ranged from 0.2 to 2.9, with the larger AOD correlated to the intense BBA layer. Such a large AOD is unprecedented in the UK according to AERONET records for the last 20 years. The Raman lidars permitted the measurement of the aerosol extinction coefficient at 355 nm, the particle linear depolarisation ratio (PLDR), and the lidar ratio (LR) and made the separation of the dust (depolarising) aerosol from other aerosol types possible. A specific extinction has also been computed to provide an estimate of the atmospheric concentration of both aerosol types separately, which peaked at 420±200 µg m−3 for the dust and 558±232 µg m−3 for the biomass burning aerosols. Back trajectories computed using the Numerical Atmospheric-dispersion Modelling Environment (NAME) were used to identify the sources and strengthen the conclusions drawn from the observations. The UK network represents a significant expansion of the observing capability in northern Europe, with instruments evenly distributed across Great Britain, from Camborne in Cornwall to Lerwick in the Shetland Islands, and this study represents the first attempt to demonstrate its capability and validate the methods in use. Its ultimate purpose will be the detection and quantification of volcanic plumes, but the present study clearly demonstrates the advanced capabilities of the network.


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