Vertical distribution of BrO in the boundary layer at the Dead Sea

2015 ◽  
Vol 12 (4) ◽  
pp. 438 ◽  
Author(s):  
Robert Holla ◽  
Stefan Schmitt ◽  
Udo Frieß ◽  
Denis Pöhler ◽  
Jutta Zingler ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Ground Level ◽  
Dead Sea ◽  
Chemical Processes ◽  
Optical Absorption Spectroscopy ◽  
Transport Barriers ◽  
Reactive Halogen Species ◽  
The Dead ◽  
High Concentrations ◽  
First Time

Environmental context Reactive halogen species affect chemical processes in the troposphere in many ways. The reactive bromine species bromine monoxide (BrO) is found in high concentrations at the Dead Sea, but processes for its formation and its spatial distribution are largely unknown. Information on the vertical distribution of BrO at the Dead Sea obtained in this work may give insight into the processes leading to BrO release and its consequences. Abstract We present results of multi-axis differential optical absorption spectroscopy (MAX‐DOAS) and long‐path DOAS (LP‐DOAS) measurements from two measurement campaigns at the Dead Sea in 2002 and 2012. The special patterns of its dynamics and topography in combination with the high salt and especially bromide content of its water lead to the particular large atmospheric abundances of more than 100 ppt BrO close to the ground and in several hundred meters above ground level. We conclude that vertical transport barriers induced by the special dynamics in the Dead Sea Valley lead to an accumulation of aerosol and reactive bromine species. This occurs in situations of weak synoptic winds and of mountain induced thermal circulations. Thus BrO release strongly depends on the topography and local and meso-scale meteorology. In case of strong zonal winds, the Dead Sea valley is flushed and high BrO levels cannot accumulate. NO2 levels below 1–2 ppb seem to be a prerequisite for a high BrO production. We assume that at least a part of the missing NO2 might be converted to BrONO2 leading to a deposition of nitrate within the aerosol and acting as a reservoir for reactive bromine. From these measurements, it was possible for the first time to simultaneously retrieve vertical profiles of aerosols, BrO and NO2 and gain also information on the distribution at the Dead Sea, allowing for a thorough characterization of the chemical processes leading to halogen release in the context of the special atmospheric dynamics in the Dead Sea Valley.

The geohydrology and water quality of the springs and wells of the western catchment to the Dead Sea, West Bank, Palestine

2000 ◽  
Vol 42 (1-2) ◽  
pp. 7-12 ◽  
Author(s):  
A. Abed Rabbo
Keyword(s):  
Hard Water ◽  
Dead Sea ◽  
Negative Effects ◽  
Salinity Hazard ◽  
Exchange Processes ◽  
Seasonal Basis ◽  
Chloride Water ◽  
The Dead ◽  
High Concentrations

This study is based on the analysis of water samples collected on a seasonal basis from the wells and springs of the southern basins of the Mountain Aquifer. The Herodion-Beit Fajjar well field is located near the main recharge area between Bethlehem and Hebron. The springs discharge from perched aquifers, or discharge directly into the Dead Sea. The analyses of the samples collected indicate three major water types: calcium carbonate water, calcium-sodium bicarbonate water, sodium chloride water; attributed to the geochemical dissolution and ion exchange processes and to mixing with wastewater. A large number of the samples are contaminated with fecal coliform and therefore unsuitable for drinking without proper disinfection. Most samples range between hard and very hard water indicating high concentrations of calcium and bicarbonte. Some of the samples exceed the nitrates limits of the WHO (1995) and a few exceed the potassium limits, indicating pollution and mixing with wastewater. Chemical treatment is required in order to bring such water up to acceptable drinking water standards. The samples registered a low sodicity and a high salinity hazard. This type of water should be limited and controlled in order to mitigate the possible negative effects on both the soil and the cultivation of plants.

scholarly journals Current challenges in modelling far-range air pollution induced by the 2014–2015 Bárðarbunga fissure eruption (Iceland)

2016 ◽  
Vol 16 (17) ◽  
pp. 10831-10845 ◽  
Author(s):  
Marie Boichu ◽  
Isabelle Chiapello ◽  
Colette Brogniez ◽  
Jean-Christophe Péré ◽  
Francois Thieuleux ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Vertical Distribution ◽  
Planetary Boundary Layer ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Ground Level ◽  
Optical Absorption Spectroscopy ◽  
Sulfate Aerosols ◽  
Volcanic Cloud

Abstract. The 2014–2015 Holuhraun lava-flood eruption of Bárðarbunga volcano (Iceland) emitted prodigious amounts of sulfur dioxide into the atmosphere. This eruption caused a large-scale episode of air pollution throughout Western Europe in September 2014, the first event of this magnitude recorded in the modern era. We gathered chemistry-transport simulations and a wealth of complementary observations from satellite sensors (OMI, IASI), ground-based remote sensing (lidar, sunphotometry, differential optical absorption spectroscopy) and ground-level air quality monitoring networks to characterize both the spatial-temporal distributions of volcanic SO2 and sulfate aerosols as well as the dynamics of the planetary boundary layer. Time variations of dynamical and microphysical properties of sulfate aerosols in the aged low-tropospheric volcanic cloud, including loading, vertical distribution, size distribution and single scattering albedo, are provided. Retrospective chemistry-transport simulations at low horizontal resolution (25 km  ×  25 km) capture the correct temporal dynamics of this far-range air pollution event but fail to reproduce the correct magnitude of SO2 concentration at ground-level. Simulations at higher spatial resolution, relying on two nested domains with finest resolution of 7.3 km  ×  7.3 km, improve substantially the far-range vertical distribution of the volcanic cloud and subsequently the description of ground-level SO2 concentrations. However, remaining discrepancies between model and observations are shown to result from an inaccurate representation of the planetary boundary layer (PBL) dynamics. Comparison with lidar observations points out a systematic under-estimation of the PBL height by the model, whichever the PBL parameterization scheme. Such a shortcoming impedes the capture of the overlying Bárðarbunga cloud into the PBL at the right time and in sufficient quantities. This study therefore demonstrates the key role played by the PBL dynamics in accurately modelling large-scale volcanogenic air pollution.

scholarly journals Modelling chemistry over the Dead Sea: bromine and ozone chemistry

2009 ◽  
Vol 9 (1) ◽  
pp. 4525-4565 ◽  
Author(s):  
L. Smoydzin ◽  
R. von Glasow
Keyword(s):  
Gas Phase ◽  
Sea Water ◽  
Dead Sea ◽  
Chemical Mechanism ◽  
Polar Regions ◽  
Model Calculations ◽  
Halogen Compounds ◽  
Reactive Halogen Species ◽  
The Dead ◽  
Halogen Species

Abstract. Measurements of O3 and BrO concentrations over the Dead Sea indicate that Ozone Depletion Events (ODEs), widely known to happen in polar regions, are also likely to occur over the Dead Sea due to the very high bromine content of the Dead Sea water. However, we show that BrO and O3 levels as they are detected cannot solely be explained by high Br− levels in the Dead Sea water and the release of gas phase halogen species out of sea borne aerosol particles and their conversion to reactive halogen species. It is likely that other sources for reactive halogen compounds are needed to explain the observed concentrations for BrO and O3. To explain the chemical mechanism taking place over the Dead Sea leading to BrO levels of several pmol/mol we used the single column model MISTRA which calculates microphysics, meteorology, gas and aerosol phase chemistry. We performed pseudo Lagrangian studies by letting the model column first move over the desert which surrounds the Dead Sea region and then let it move over the Dead Sea itself. To include an additional source for gas phase halogen compounds, gas exchange between the Dead Sea water and the atmosphere is treated explicitly. Model calculations indicate that this process has to be included to explain the measurements.

scholarly journals Measurement-based modeling of bromine chemistry at the Dead Sea boundary layer – Part 2: The influence of NO<sub>2</sub> on bromine chemistry at mid-latitude areas

2008 ◽  
Vol 8 (2) ◽  
pp. 7725-7753
Author(s):  
E. Tas ◽  
M. Peleg ◽  
D. U. Pedersen ◽  
V. Matveev ◽  
A. P. Biazar ◽  
...  
Keyword(s):  
Field Measurements ◽  
Threshold Level ◽  
Companion Paper ◽  
Dead Sea ◽  
Anthropogenic Activity ◽  
Polar Regions ◽  
Mixing Ratios ◽  
Daily Average ◽  
Reactive Halogen Species ◽  
The Dead

Abstract. Understanding the interaction between anthropogenic air pollution and Reactive Halogen Species (RHS) activity has had only limited support of direct field measurements, due to the fact that past field measurements of RHS have been mainly performed in Polar Regions. The present paper investigates the interaction between NO2 and Reactive Bromine Species (RBS) activity by model simulations based on extensive field measurements performed in the Dead Sea area, as described in a companion paper (Tas et al., 2006). The Dead Sea is an excellent natural laboratory for this investigation since elevated concentrations of BrO (up to more than 150 pptv) are frequently observed, while the average levels of NO2 are around several ppb. The results of the present study show that under the chemical mechanisms that occur at the Dead Sea, higher levels of NO2 lead to higher daily average concentrations of BrOX, as a result of an increase in the rate of the heterogeneous decomposition of BrONO2 that in turn causes an increase in the rate of the "Bromine Explosion" mechanism. The present study has shown that the influence of NO2 on BrOX production clearly reflects an enhancement of RBS activity caused by anthropogenic activity. However, above a certain threshold level of NO2 (daily average mixing ratios of 0.2 ppbv during RBS activity), the daily average concentrations of BrOX decrease for a further increase in the NO2 concentrations.

The Dead Sea earthquake of 23 April 1979

1982 ◽  
Vol 72 (5) ◽  
pp. 1627-1634
Author(s):  
E. Arieh ◽  
Y. Rotstein ◽  
U. Peled
Keyword(s):  
Strong Motion ◽  
Dead Sea ◽  
Fault System ◽  
Peak Ground Accelerations ◽  
Epicentral Distribution ◽  
The Dead ◽  
Active Segment ◽  
First Time ◽  
Intensity Study

abstract The Dead Sea earthquake of 23 April 1979 (mb = 5.1) was felt throughout Israel and in parts of the neighboring countries. The epicentral distribution of this earthquake, its aftershocks, two of the largest Dead Sea earthquakes during the last 50 yr and recent microearthquake data suggest that an active segment of the Dead Sea rift fault system lies along the eastern part of the Dead Sea. A detailed intensity study shows a pronounced dependence of seismic intensities on ground characteristics. Strong motion seismograph measurements were obtained for the first time in the Levant countries and they suggest that peak ground accelerations are not significantly different from worldwide data.

Economic valuation of resuscitating the Dead Sea

Water Policy ◽  
2006 ◽  
Vol 8 (4) ◽  
pp. 351-370 ◽  
Author(s):  
Nir Becker ◽  
David Katz
Keyword(s):  
Stated Preference ◽  
Economic Valuation ◽  
Economic Value ◽  
Revealed Preference ◽  
Dead Sea ◽  
Dead Sea Basin ◽  
Market Economic ◽  
Study Results ◽  
The Dead ◽  
First Time

As a result of diversion of upstream waters and intensive mineral extraction along its shores, the level of the Dead Sea is dropping at a rate of almost one meter per year, causing the sea continuously to break its own record as the lowest place on earth. The loss of the sea and the accompanying ecological and cultural damage in the basin has traditionally been regarded as an unavoidable consequence of rational economic policy. This study investigates for the first time the non-market economic value of conservation of the Dead Sea basin using both contingent valuation (stated preference) and travel cost (revealed preference) studies. Study results indicate that all three local populations, Israeli, Jordanian and Palestinian, demonstrate a substantial willingness to pay to preserve the cultural and environmental heritage of the region. Such results strengthen the case for conservation of the region, which, heretofore, has relied strictly on ethical and ecological rationales.

scholarly journals Modelling chemistry over the Dead Sea: bromine and ozone chemistry

2009 ◽  
Vol 9 (14) ◽  
pp. 5057-5072 ◽  
Author(s):  
L. Smoydzin ◽  
R. von Glasow
Keyword(s):  
Gas Phase ◽  
Sea Water ◽  
Dead Sea ◽  
Chemical Mechanism ◽  
Polar Regions ◽  
Model Calculations ◽  
Halogen Compounds ◽  
Reactive Halogen Species ◽  
The Dead ◽  
Halogen Species

Abstract. Measurements of O3 and BrO concentrations over the Dead Sea indicate that Ozone Depletion Events (ODEs), widely known to happen in polar regions, are also occuring over the Dead Sea due to the very high bromine content of the Dead Sea water. However, we show that BrO and O3 levels as they are detected cannot solely be explained by high Br− levels in the Dead Sea water and the release of gas phase halogen species out of sea borne aerosol particles and their conversion to reactive halogen species. It is likely that other sources for reactive halogen compounds are needed to explain the observed concentrations for BrO and O3. To explain the chemical mechanism taking place over the Dead Sea leading to BrO levels of several pmol/mol we used the one-dimensional model MISTRA which calculates microphysics, meteorology, gas and aerosol phase chemistry. We performed pseudo Lagrangian studies by letting the model column first move over the desert which surrounds the Dead Sea region and then let it move over the Dead Sea itself. To include an additional source for gas phase halogen compounds, gas exchange between the Dead Sea water and the atmosphere is treated explicitly. Model calculations indicate that this process has to be included to explain the measurements.

scholarly journals Measurement-based modeling of bromine chemistry in the Dead Sea boundary layer – Part 2: The influence of NO<sub>2</sub> on bromine chemistry at mid-latitude areas

2008 ◽  
Vol 8 (16) ◽  
pp. 4811-4821 ◽  
Author(s):  
E. Tas ◽  
M. Peleg ◽  
D. U. Pedersen ◽  
V. Matveev ◽  
A. P. Biazar ◽  
...  
Keyword(s):  
Field Measurements ◽  
Threshold Level ◽  
Companion Paper ◽  
Dead Sea ◽  
Anthropogenic Activity ◽  
Polar Regions ◽  
Mixing Ratios ◽  
Daily Average ◽  
Reactive Halogen Species ◽  
The Dead

Abstract. Understanding the interaction between anthropogenic air pollution and Reactive Halogen Species (RHS) activity has had only limited support from direct field measurements, due to the fact that past field measurements of RHS have been mainly performed in Polar Regions. The present paper investigates the interaction between NO2 and Reactive Bromine Species (RBS) activity by model simulations based on extensive field measurements performed in the Dead Sea area, as described in a companion paper (Tas et al., 2006). The Dead Sea is an excellent natural laboratory for this investigation since elevated mixing ratios of BrO (up to more than 150 pptv) are frequently observed, while the average levels of NO2 are around several ppb. The results of the present study show that under the chemical mechanisms that occur at the Dead Sea, higher levels of NO2 lead to higher daily average mixing ratios of BrOx. This is the result of an increase in the rate of the heterogeneous decomposition of BrONO2, which in turn causes an increase in the rate of the "Bromine Explosion" mechanism. However, above a certain threshold level of NO2 (daily average mixing ratios of 0.2 ppbv during RBS activity), the daily average mixing ratios of BrOx decrease for a further increase in the NO2 mixing ratios. This investigation shows that the influence of NO2 on BrOx production clearly reflects an enhancement of RBS activity caused by anthropogenic activity.

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