scholarly journals Reactive nitrogen around the Arabian Peninsula and in the Mediterranean Sea during the 2017 AQABA ship campaign

2021 ◽  
Author(s):  
Nils Friedrich ◽  
Philipp Eger ◽  
Justin Shenolikar ◽  
Nicolas Sobanski ◽  
Jan Schuladen ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Red Sea ◽  
Thermal Dissociation ◽  
Arabian Gulf ◽  
Gas Production ◽  
Ozone Production ◽  
Organic Nitrates ◽  
Oxides Of Nitrogen ◽  
Regional Variability ◽  
The Mediterranean

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 %).

scholarly journals Reactive nitrogen around the Arabian Peninsula and in the Mediterranean Sea during the 2017 AQABA ship campaign

2021 ◽  
Vol 21 (10) ◽  
pp. 7473-7498
Author(s):  
Nils Friedrich ◽  
Philipp Eger ◽  
Justin Shenolikar ◽  
Nicolas Sobanski ◽  
Jan Schuladen ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Red Sea ◽  
Thermal Dissociation ◽  
Arabian Gulf ◽  
Gas Production ◽  
Ozone Production ◽  
Organic Nitrates ◽  
Oxides Of Nitrogen ◽  
Regional Variability ◽  
The Mediterranean

Abstract. We present shipborne 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 ring-down 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. Complementing the TD-CRDS measurements, NO and NO2 data sets from a chemiluminescence detector (CLD) were used in the analysis. 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. The role of HONO was assessed by calculating the NOx production rate from its photolysis. Mean NO2 lifetimes were 3.9 h in the Mediterranean Sea, 4.0 h in the Arabian Gulf, and 5.0 h 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 (OPEs; calculated from the correlation between Ox and NOz, where Ox= O3+ NO2) 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 %).

scholarly journals Shipborne measurements of ClNO<sub>2</sub> in the Mediterranean Sea and around the Arabian Peninsula during summer

2019 ◽  
Vol 19 (19) ◽  
pp. 12121-12140 ◽  
Author(s):  
Philipp G. Eger ◽  
Nils Friedrich ◽  
Jan Schuladen ◽  
Justin Shenolikar ◽  
Horst Fischer ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Red Sea ◽  
Marine Boundary Layer ◽  
Limit Of Detection ◽  
Arabian Gulf ◽  
Early Morning ◽  
Regional Variability ◽  
Gulf Of Oman ◽  
Oxidation Rates ◽  
The Mediterranean

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.

scholarly journals Shipborne measurements of ClNO<sub>2</sub> in the Mediterranean Sea and around the Arabian Peninsula during summer

2019 ◽  
Author(s):  
Philipp G. Eger ◽  
Nils Friedrich ◽  
Jan Schuladen ◽  
Justin Shenolikar ◽  
Horst Fischer ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Red Sea ◽  
Marine Boundary Layer ◽  
Limit Of Detection ◽  
Arabian Gulf ◽  
Early Morning ◽  
Regional Variability ◽  
Gulf Of Oman ◽  
Oxidation Rates ◽  
The Mediterranean

Abstract. Shipborne measurements of nitryl chloride (ClNO2), hydrogen chloride (HCl) and sulphur 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 &amp;approx; 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 oil industry. The yield of ClNO2 formation per NO3 radical generated was generally low (median of &amp;approx; 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 VOCs, especially in the early morning.

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 ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Red Sea ◽  
Atmospheric Chemistry ◽  
Oil And Gas ◽  
Arabian Peninsula ◽  
Arabian Gulf ◽  
Suez Canal ◽  
Associated Gas ◽  
Mixing Ratios ◽  
The Mediterranean

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.

Radiocarbon dating of individual foram tests show that alleged Lessepsian species are of Holocene age

2021 ◽  
Author(s):  
Paolo G. Albano ◽  
Anna Sabbatini ◽  
Jonathan Lattanzio ◽  
Jan Steger ◽  
Sönke Szidat ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Red Sea ◽  
Native Species ◽  
Radiocarbon Dating ◽  
Suez Canal ◽  
Tropical Species ◽  
Indigenous Species ◽  
Last Interglacial ◽  
Sediment Depth ◽  
The Mediterranean

&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;

Tintinnids (Ciliophora: Choreotrichia) of the Suez Canal and their transmigration process between the Red Sea and the Mediterranean Sea

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
Keyword(s):  
Mediterranean Sea ◽  
Red Sea ◽  
Suez Canal ◽  
The Mediterranean

Local adaptation of a Lessepsian invader species to winter conditions in the Mediterranean Sea

2021 ◽  
Author(s):  
Débora Silva Raposo ◽  
Raphaël Morard ◽  
Christiane Schmidt ◽  
Michal Kucera
Keyword(s):  
Quantum Yield ◽  
Mediterranean Sea ◽  
Red Sea ◽  
Photosynthetic Activity ◽  
Eastern Mediterranean ◽  
Effective Quantum Yield ◽  
Mediterranean Populations ◽  
Cold Temperatures ◽  
Invasion Front ◽  
The Mediterranean

&lt;p&gt;In recent decades the &amp;#8220;Lessepsian&amp;#8221; migration caused a rapid change in the marine community composition due to the invasion of alien species from the Red Sea into the Mediterranean Sea. Among these invaders is the large benthic foraminifera &lt;em&gt;Amphistegina lobifera&lt;/em&gt;, a diatom-bearing species that recently reached the invasion front in Sicily. There it copes with colder winters and broader temperature than in its original source, the Red Sea. It is not yet known how (or if) the population from the invasion front has developed adaptation to this new thermal regime. Understanding the modern marine invasive patterns is a crucial tool to predict future invasive successes in marine environments. Therefore, in this study we aim to evaluate the physiological responses to cold temperatures of &lt;em&gt;A. lobifera&lt;/em&gt; populations at three different invasive stages: source (Red Sea), early invader (Eastern Mediterranean) and invasion front (Sicily). For this, we conducted a culturing experiment in which we monitored the responses of the foraminifera (growth, motility) to temperatures of 10, 13, 16, 19&amp;#176;C + control (25&amp;#176;C) over four weeks. To address what is the role of their endosymbionts in the adaptation process, we also monitored their photosynthetic activity (Pulse Amplitude Modulation - PAM fluorometer) during the experiment. The growth rate of the foraminifera was reduced for all populations below 19&amp;#176;C as well as the motility, reduced until 16&amp;#176;C and dropping to zero below 13&amp;#176;C. The response of the endosymbionts was however different. There was a reduced photosynthetic activity of the Red Sea and Eastern Mediterranean populations at colder temperatures observed by the lower maximum quantum yield (Fv:Fm) and effective quantum yield (Y(II)), when compared to their initial levels and to the other treatments. In the meantime, the endosymbionts of the Sicily population stood out with the highest photosynthetic activity (Fv:Fm and Y(II)) in the treatments bellow 13 &amp;#176;C (P &lt; 0.05). In conclusion, we observed that while the host responses were similar between the three populations, the endosymbionts from the invasion front population shows the best performance at colder temperatures. This suggests that the photo-symbiosis has an important role in adaptation, most likely being a key factor to the success of past and future migrations.&lt;/p&gt;

Present Development Phases of the Suez Canal Project

1982 ◽  
Vol 35 (3) ◽  
pp. 460-465
Author(s):  
Nabil Hilaly
Keyword(s):  
Mediterranean Sea ◽  
Red Sea ◽  
World Trade ◽  
Nile Delta ◽  
Suez Canal ◽  
Development Phases ◽  
The Mediterranean

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.

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