scholarly journals Non-methane hydrocarbon (C<sub>2</sub>–C<sub>8</sub>) sources and sinks around the Arabian Peninsula

2019 ◽  
Vol 19 (10) ◽  
pp. 7209-7232 ◽  
Author(s):  
Efstratios Bourtsoukidis ◽  
Lisa Ernle ◽  
John N. Crowley ◽  
Jos Lelieveld ◽  
Jean-Daniel Paris ◽  
...  

Abstract. Atmospheric non-methane hydrocarbons (NMHCs) have been extensively studied around the globe due to their importance to atmospheric chemistry and their utility in emission source and chemical sink identification. This study reports on shipborne NMHC measurements made around the Arabian Peninsula during the AQABA (Air Quality and climate change in the Arabian BAsin) ship campaign. The ship traversed the Mediterranean Sea, the Suez Canal, the Red Sea, the northern Indian Ocean, and the Arabian Gulf, before returning by the same route. The Middle East is one of the largest producers of oil and gas (O&amp;G), yet it is among the least studied. Atmospheric mixing ratios of C2–C8 hydrocarbons ranged from a few ppt in unpolluted regions (Arabian Sea) to several ppb over the Suez Canal and Arabian Gulf (also known as the Persian Gulf), where a maximum of 166.5 ppb of alkanes was detected. The ratio between i-pentane and n-pentane was found to be 0.93±0.03 ppb ppb−1 over the Arabian Gulf, which is indicative of widespread O&amp;G activities, while it was 1.71±0.06 ppb ppb−1 in the Suez Canal, which is a characteristic signature of ship emissions. We provide evidence that international shipping contributes to ambient C3–C8 hydrocarbon concentrations but not to ethane, which was not detected in marine traffic exhausts. NMHC relationships with propane differentiated between alkane-rich associated gas and methane-rich non-associated gas through a characteristic enrichment of ethane over propane atmospheric mixing ratios. Utilizing the variability–lifetime relationship, we show that atmospheric chemistry governs the variability of the alkanes only weakly in the source-dominated areas of the Arabian Gulf (bAG=0.16) and along the northern part of the Red Sea (bRSN=0.22), but stronger dependencies are found in unpolluted regions such as the Gulf of Aden (bGA=0.58) and the Mediterranean Sea (bMS=0.48). NMHC oxidative pair analysis indicated that OH chemistry dominates the oxidation of hydrocarbons in the region, but along the Red Sea and the Arabian Gulf the NMHC ratios occasionally provided evidence of chlorine radical chemistry. These results demonstrate the utility of NMHCs as source/sink identification tracers and provide an overview of NMHCs around the Arabian Peninsula.

2019 ◽  
Author(s):  
Efstratios Bourtsoukidis ◽  
Lisa Ernle ◽  
John N. Crowley ◽  
Jos Lelieveld ◽  
Jean-Daniel Paris ◽  
...  

Abstract. Atmospheric Non Methane Hydrocarbons (NMHC) have been extensively studied around the globe due to their importance to atmospheric chemistry and their utility in emission source and chemical sink identification. This study reports on shipborne NMHC measurements made around the Arabian Peninsula during the AQABA (Air Quality and climate change in the Arabian BAsin) ship campaign. The ship traversed the Mediterranean Sea, the Suez Canal, the Red Sea, the Northern Indian Ocean and the Arabian Gulf, before returning by the same route. This region is one of the largest producers of oil and gas (O&amp;G); yet it is among the least studied. Atmospheric mixing ratios of C2–C8 hydrocarbons ranged from a few ppt in unpolluted regions (Arabian Sea) to several ppb over the Suez Canal and Arabian Gulf where a maximum of 166.5 ppb of alkanes was detected. The ratio between i-pentane and n-pentane was found to be 0.93 ± 0.03 ppb ppb−1 over the Arabian Gulf which is indicative of widespread O&amp;G activities, while it was 1.71 ± 0.06 ppb ppb−1 in the Suez Canal which is a characteristic signature for ship emissions. We provide evidence that international shipping contributes to ambient C3–C8 hydrocarbon concentrations but not to ethane which was not detected in marine traffic exhausts. NMHC relationships with propane differentiated between alkane-rich associated gas and methane-rich non-associated gas through a characteristic enrichment of ethane over propane atmospheric mixing ratios. Utilizing the variability-lifetime relationship, we show that atmospheric chemistry governs the variability of the alkanes only weakly in the source dominated areas of the Arabian Gulf (bAG = 0.16) and along the northern part of Red Sea (bRSN = 0.22), but stronger dependencies are found in unpolluted regions such as the Gulf of Aden (bGA = 0.58) and Mediterranean Sea (bMS = 0.48). NMHC oxidative pair analysis indicated that OH chemistry dominates the oxidation of hydrocarbons in the region but along the Red Sea and the Arabian Gulf the NMHC ratios occasionally provided evidence for chlorine radical chemistry. These results demonstrate the utility of NMHCs as source/sink identification tracers and provide an overview of NMHCs around the Arabian Peninsula.


2021 ◽  
Author(s):  
Paolo G. Albano ◽  
Anna Sabbatini ◽  
Jonathan Lattanzio ◽  
Jan Steger ◽  
Sönke Szidat ◽  
...  

&lt;p&gt;The Lessepsian invasion &amp;#8211; the largest marine biological invasion &amp;#8211; followed the opening of the Suez Canal in 1869 (81 years BP). Shortly afterwards, tropical species also distributed in the Red Sea appeared on Mediterranean shores: it was the dawn of what would become the invasion of several hundred tropical species. The time of the Suez Canal opening coincided with an acceleration in natural history exploration and description, but the eastern sectors of the Mediterranean Sea lagged behind and were thoroughly explored only in the second half of the 20&lt;sup&gt;th&lt;/sup&gt; century. Many parts are still insufficiently studied today. Baseline information on pre-Lessepsian ecosystem states is thus scarce. This knowledge gap has rarely been considered by invasion scientists: every new finding of species belonging to tropical clades has been assumed to be a Lessepsian invader.&lt;/p&gt;&lt;p&gt;We here question this assumption by radiocarbon dating seven individual tests of miliolids &amp;#8211; imperforated calcareous foraminifera &amp;#8211; belonging to five alleged non-indigenous species. Tests were found in two sediment cores collected at 30 and 40 m depth off Ashqelon, on the Mediterranean Israeli shelf. We dated one &lt;em&gt;Cribromiliolinella milletti &lt;/em&gt;(core at 40 m, 20 cm sediment depth), three &lt;em&gt;Nodophthalmidium antillarum &lt;/em&gt;(core at 40 m, 35 cm sediment depth), one &lt;em&gt;Miliolinella &lt;/em&gt;cf. &lt;em&gt;fichteliana &lt;/em&gt;(core at 30 m, 110 cm sediment depth), one &lt;em&gt;Articulina alticostata &lt;/em&gt;(core at 40 m, 35 cm sediment depth) and one &lt;em&gt;Spiroloculina antillarum &lt;/em&gt;(core at 30 m, 110 cm sediment depth). All foraminiferal tests proved to be of Holocene age, with a median calibrated age spanning between 749 and 8285 years BP. Only one test of &lt;em&gt;N. antillarum&lt;/em&gt; showed a 2-sigma error overlapping the time of the opening of the Suez Canal, but with a median age of 1123 years BP. Additionally, a thorough literature search resulted in a further record of &lt;em&gt;S. antillarum&lt;/em&gt; in a core interval dated 1820&amp;#8211;2064 years BP in Turkey.&lt;/p&gt;&lt;p&gt;Therefore, these foraminiferal species are not introduced, but native species. They are all circumtropical or Indo-Pacific and in the Mediterranean distributed mostly in the eastern sectors (only &lt;em&gt;S. antillarum&lt;/em&gt; occurs also in the Adriatic Sea). Two hypotheses can explain our results: these species are Tethyan relicts that survived the Messinian salinity crisis (5.97&amp;#8211;5.33 Ma) and the glacial periods of the Pleistocene in the Eastern Mediterranean, which may have never desiccated completely during the Messinian crisis and which may have worked as a warm-water refugium in the Pleistocene; or they entered the Mediterranean Sea from the Red Sea more recently but before the opening of the Suez Canal, for example during the Last Interglacial (MIS5e) high-stand (125,000 years BP) when the flooded Isthmus of Suez enabled exchanges between the Mediterranean and the Indo-Pacific fauna. The recognition that some alleged Lessepsian invaders are in fact native species influences our understanding of the invasion process, its rates and environmental correlates.&lt;/p&gt;


2014 ◽  
Vol 17 (4) ◽  
pp. 454-462
Author(s):  
Hamed A. El-Serehy ◽  
Fahad A. Al-Misned ◽  
Nasser S. Abdel-Rahman ◽  
Khaled A. Al-Rasheid

1982 ◽  
Vol 35 (3) ◽  
pp. 460-465
Author(s):  
Nabil Hilaly

It is recorded that Egypt was the first country to dig a canal to promote world trade; the first canal was dug in the reign of Pharaoh Senusret III (1887–1849 B.C.), to link the Mediterranean Sea with the Red Sea through the Nile delta. This canal, often abandoned due to silting, was reopened for navigation by later Pharaohs and finally by Amro Ibn El Ass in A.D. 640 after which it remained open for 150 years.


2021 ◽  
Author(s):  
Jean-Daniel Paris ◽  
Aurélie Riandet ◽  
Efstratios Bourtsoukidis ◽  
Marc Delmotte ◽  
Antoine Berchet ◽  
...  

Abstract. The increase of atmospheric methane (CH4) and carbon dioxide (CO2), two main anthropogenic greenhouse gases, is largely driven by fossil sources. Sources and sinks remain insufficiently characterised in the Mediterranean and Middle East areas, where very few in situ measurements area available. We investigated the atmospheric distribution of CH4 and CO2 in the region through shipborne measurement in July and August 2017. High mixing ratios were observed over the Suez Canal, Red Sea and Arabian Gulf, while generally lower mixing ratios were observed over the Gulfs of Aden and Oman. We probe the origin of CO2 and CH4 excess mixing ratio by using correlations with light alkanes and through the use of a Lagrangian model coupled to two different emission inventories of anthropogenic sources. We find that the CO2 and especially the CH4 enhancements are mainly linked to nearby oil and gas (O&amp;G) activities over the Arabian Gulf, and a mixture of other sources over the Red Sea. The isomeric ratio of pentane is shown to be a useful indicator of the O&amp;G component of atmospheric CH4 at the regional level. Upstream emissions linked to oil in the Northern Arabian Gulf seem to be underestimated while gas-related emissions in the Southern Gulf are overestimated in our simulations. Our results highlight the need for improvement of inventories in the area to better characterize the changes in magnitude and the complex distribution of the O&amp;G sources in the Middle East.


2019 ◽  
Vol 19 (19) ◽  
pp. 12121-12140 ◽  
Author(s):  
Philipp G. Eger ◽  
Nils Friedrich ◽  
Jan Schuladen ◽  
Justin Shenolikar ◽  
Horst Fischer ◽  
...  

Abstract. Shipborne measurements of nitryl chloride (ClNO2), hydrogen chloride (HCl) and sulfur dioxide (SO2) were made during the AQABA (Air Quality and climate change in the Arabian BAsin) ship campaign in summer 2017. The dataset includes measurements over the Mediterranean Sea, the Suez Canal, the Red Sea, the Gulf of Aden, the Arabian Sea, the Gulf of Oman, and the Arabian Gulf (also known as Persian Gulf) with observed ClNO2 mixing ratios ranging from the limit of detection to ≈600 pptv. We examined the regional variability in the generation of ClNO2 via the uptake of dinitrogen pentoxide (N2O5) to Cl-containing aerosol and its importance for Cl atom generation in a marine boundary layer under the (variable) influence of emissions from shipping and the oil industry. The yield of ClNO2 formation per NO3 radical generated was generally low (median of ≈1 %–5 % depending on the region), mainly as a result of gas-phase loss of NO3 dominating over heterogeneous loss of N2O5, the latter being disfavoured by the high temperatures found throughout the campaign. The contributions of ClNO2 photolysis and OH-induced HCl oxidation to Cl-radical formation were derived and their relative contributions over the diel cycle compared. The results indicate that over the northern Red Sea, the Gulf of Suez, and the Gulf of Oman the formation of Cl atoms will enhance the oxidation rates of some volatile organic compounds (VOCs), especially in the early morning.


2010 ◽  
Vol 11 (2) ◽  
pp. 369 ◽  
Author(s):  
C. TURAN ◽  
D. YAGLIOGLU ◽  
D. ERGUDEN ◽  
M. GURLEK ◽  
B. SONMEZ

Two specimens of the alien cardinal fish Apogon fasciatus (White, 1790) are recorded for the first time from Turkey and second time from the Mediterranean Sea. This is the fourth Indo-Pacific apogonid species documented in the Mediterranean Sea, and the introduction of this species to the eastern Mediterranean is due to migration from the Red Sea via the Suez Canal.


2021 ◽  
Author(s):  
Nils Friedrich ◽  
Philipp Eger ◽  
Justin Shenolikar ◽  
Nicolas Sobanski ◽  
Jan Schuladen ◽  
...  

Abstract. We present ship-borne measurements of NOx (≡ NO + NO2) and NOy (≡ NOx + gas- and particle-phase organic and inorganic oxides of nitrogen) in summer 2017 as part of the expedition Air Quality and climate change in the Arabian Basin (AQABA). The NOx and NOz (≡ NOy–NOx) measurements, made with a thermal dissociation cavity-ringdown-spectrometer (TD-CRDS), were used to examine the chemical mechanisms involved in the processing of primary NOx emissions and their influence on the NOy budget in chemically distinct marine environments, including the Mediterranean Sea, the Red Sea, and the Arabian Gulf which were influenced to varying extents by emissions from shipping and oil and gas production. In all regions, we find that NOx is strongly connected to ship emissions, both via direct emission of NO and via the formation of HONO and its subsequent photolytic conversion to NO. Mean NO2 lifetimes were 3.9 hours in the Mediterranean Sea, 4.0 hours in the Arabian Gulf and 5.0 hours in the Red Sea area. The cumulative loss of NO2 during the night (reaction with O3) was more important than daytime losses (reaction with OH) over the Arabian Gulf (by a factor 2.8) and over the Red Sea (factor 2.9), whereas over the Mediterranean Sea, where OH levels were high, daytime losses dominated (factor 2.5). Regional ozone production efficiencies (OPE) ranged from 10.5 ± 0.9 to 19.1 ± 1.1. This metric quantifies the relative strength of photochemical O3 production from NOx, compared to the competing sequestering into NOz species. The largest values were found over the Arabian Gulf, consistent with high levels of O3 found in that region (10–90 percentiles range: 23–108 ppbv). The fractional contribution of individual NOz species to NOy exhibited a large regional variability, with HNO3 generally the dominant component (on average 33 % of NOy) with significant contributions from organic nitrates (11 %) and particulate nitrates in the PM1 size range (8 %).


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