Mineral springs in the Suez Rift Valley — Comparison with waters in the Jordan Rift valley and postulation of a marine origin     

E. Mazor  A. Nadler  M. Molcho 《Journal of Hydrology》1973,20(4):289-309

Fresh and mineral waters from the eastern margin of the Suez Rift Valley are described. They include a fair number of sources that resemble the mineral waters in the Jordan Rift Valley. The term Tiberias-Farun water is thus suggested to describe them. They are characterized compositionally by Cl > Na (in equiv.), the presence of NaCl and MgCl₂, a Cl/Br ratio (by weight) around 150, elevated radium and H₂S content, elevated temperature, a light stable-isotope composition and high carbon-14 age.

The Tiberias-Farun waters are suggested to have originated from entrapped seawater that gradually changed in composition by interaction with aquifer rocks. Such changes were demonstrated to take place in the laboratory experiments.  相似文献   

Evolution of fumarolic gases — boundary conditions set by measured parameters: case study at Vulcano,Italy     

E. Mazor  R. Cioni  E. Corazza  M. Fratta  G. Magro  S. Matsuo  J. Hirabayashi  H. Shinohara  M. Martini  G. Piccardi  P. Cellini-Legittimo 《Bulletin of Volcanology》1988,50(2):71-85

Physical, chemical and isotopic parameters were measured in fumaroles at the Vulcano crater and in drowned fumaroles near the beach. The data were used to define boundary conditions for possible conceptual models of the system.Crater fumaroles: time variations of CO₂ and SO₂ concentrations indicate mixing of saline gas-rich water with local fresh water. Cl/Br ratios of 300– 400 favour sea-water as a major source for Cl, Brand part of the water in the fumaroles. Cl concentrations and D values revealed, independently, amixing of 0.75 sea-water with 0.25 local freshwaterin furmarole F-5 during September 1982.Patterns of parameter correlation and mass balances reveal that CO₂, S, NH₃ and B originate from sources other than sea water. The CO₂ value of ¹³C = – 2%_o favours, at least partial, origin from decomposition of sedimentary rocks rather than mantle-derived material. Radiogenic⁴He(1.3 × lO^–3 ccSTP/g water) and radiogenic⁴⁰Ar(10.6 × 10^–4 ccSTP/g water) are observed, (⁴He/⁴⁰Ar)_radiogenic = 1.2, well in the range of values observed in geothermal systems.Drowned fumaroles: strongly bubbling gas at a pond and at the beachappears to have the same origin and initial compositionas the crater fumaroles (2 km away). The fumarolic gas is modified by depletion of the reactive gases, caused by dissolution in shallow-water. Atmospheric Ne, Ar, Kr and Xe are addeden route, some radiogenic He and Ar are maintained. The Vulcano system seems to be strongly influenced by the contribution of sea-water and decomposition of sedimentary rocks. Evidence of magmatic contributions is mainly derived from heat.  相似文献   

The science of European marine reserves: Status,efficacy, and future needs     

Phillip B. Fenberg  Jennifer E. Caselle  Joachim Claudet  Michaela Clemence  Steven D. Gaines  Jose Antonio García-Charton  Emanuel J. Gonçalves  Kirsten Grorud-Colvert  Paolo Guidetti  Stuart R. Jenkins  Peter J.S. Jones  Sarah E. Lester  Rob McAllen  Even Moland  Serge Planes  Thomas K. Sørensen 《Marine Policy》2012

The ecologically and socio-economically important marine ecosystems of Europe are facing severe threats from a variety of human impacts. To mitigate and potentially reverse some of these impacts, the European Union (EU) has mandated the implementation of the Marine Strategy Framework Directive (MSFD) in order to achieve Good Environmental Status (GES) in EU waters by 2020. The primary initiative for achieving GES is the implementation of coherent networks of marine protected areas (MPAs). Marine reserves are an important type of MPA in which no extraction is allowed, but their usefulness depends upon a number of ecological, management, and political factors. This paper provides a synthesis of the ecological effects of existing European marine reserves and the factors (social and ecological) underlying their effectiveness. Results show that existing European marine reserves foster significant positive increases in key biological variables (density, biomass, body size, and species richness) compared with areas receiving less protection, a pattern mirrored by marine reserves around the globe. For marine reserves to achieve their ecological and social goals, however, they must be designed, managed, and enforced properly. In addition, identifying whether protected areas are ecologically connected as a network, as well as where new MPAs should be established according to the MSFD, requires information on the connectivity of populations across large areas. The adoption of the MSFD demonstrates willingness to achieve the long-term protection of Europe's marine ecosystems, but whether the political will (local, regional, and continent wide) is strong enough to see its mandates through remains to be seen. Although the MSFD does not explicitly require marine reserves, an important step towards the protection of Europe's marine ecosystems is the establishment of marine reserves within wider-use MPAs as connected networks across large spatial scales.  相似文献   

Presence of DDT and Lindane in a Karstic Groundwater Aquifer in Yucatan,Mexico          下载免费PDF全文

Germán Giácoman‐Vallejos  Irma Lizarraga‐Castro  Carmen Ponce‐Caballero  Avel González‐Sánchez  Emanuel Hernández‐Núñez 《Ground Water Monitoring & Remediation》2018,38(2):68-78

Pollution caused by pesticides is becoming relevant because of their harmful environmental effects. The persistence, bioaccumulation and toxicity of some organochloride pesticides have resulted in their restricted use since 1970 and a requirement to monitor them in many countries. Pesticides have endocrine, immunological, reproductive and carcinogenic effects in both humans and animals. The facilitated infiltration of substances results in the pollution of hydric underground resources in karstic limestone such as that found in the state of Yucatan. Observing the north occidental region of the state of Yucatan is particularly important as it is characterized by agricultural activities (wide use of pesticides), significant human settlements and underground water flows oriented towards the north coast. In this study, the underground water quality of a karstic aquifer was evaluated by quantifying the presence of organochlorine pesticides in 29 wells located throughout the Mérida‐Progreso transect, Yucatan, Mexico. The presence of DDT, lindane and their metabolites was detected at concentrations above the permissible limits stated by Mexican regulatory standards (NOM‐127‐SSA1‐1994 2010) in the majority of wells studied. Continuous monitoring of the underground hydric resources in this region is therefore essential to raising awareness of pollution risks and the vulnerability of the coastal north to the contamination of the underground water flows.  相似文献   

Convective Self-Aggregation in Numerical Simulations: A Review     

Allison A. Wing  Kerry Emanuel  Christopher E. Holloway  Caroline Muller 《Surveys in Geophysics》2017,38(6):1173-1197

Organized convection in the tropics occurs across a range of spatial and temporal scales and strongly influences cloud cover and humidity. One mode of organization found is “self-aggregation,” in which moist convection spontaneously organizes into one or several isolated clusters despite spatially homogeneous boundary conditions and forcing. Self-aggregation is driven by interactions between clouds, moisture, radiation, surface fluxes, and circulation, and occurs in a wide variety of idealized simulations of radiative–convective equilibrium. Here we provide a review of convective self-aggregation in numerical simulations, including its character, causes, and effects. We describe the evolution of self-aggregation including its time and length scales and the physical mechanisms leading to its triggering and maintenance, and we also discuss possible links to climate and climate change.  相似文献   

EUREC<Superscript>4</Superscript>A: A Field Campaign to Elucidate the Couplings Between Clouds,Convection and Circulation     

Sandrine Bony  Bjorn Stevens  Felix Ament  Sebastien Bigorre  Patrick Chazette  Susanne Crewell  Julien Delanoë  Kerry Emanuel  David Farrell  Cyrille Flamant  Silke Gross  Lutz Hirsch  Johannes Karstensen  Bernhard Mayer  Louise Nuijens  James H. RuppertJr.  Irina Sandu  Pier Siebesma  Sabrina Speich  Frédéric Szczap  Julien Totems  Raphaela Vogel  Manfred Wendisch  Martin Wirth 《Surveys in Geophysics》2017,38(6):1529-1568

Trade-wind cumuli constitute the cloud type with the highest frequency of occurrence on Earth, and it has been shown that their sensitivity to changing environmental conditions will critically influence the magnitude and pace of future global warming. Research over the last decade has pointed out the importance of the interplay between clouds, convection and circulation in controling this sensitivity. Numerical models represent this interplay in diverse ways, which translates into different responses of trade-cumuli to climate perturbations. Climate models predict that the area covered by shallow cumuli at cloud base is very sensitive to changes in environmental conditions, while process models suggest the opposite. To understand and resolve this contradiction, we propose to organize a field campaign aimed at quantifying the physical properties of trade-cumuli (e.g., cloud fraction and water content) as a function of the large-scale environment. Beyond a better understanding of clouds-circulation coupling processes, the campaign will provide a reference data set that may be used as a benchmark for advancing the modelling and the satellite remote sensing of clouds and circulation. It will also be an opportunity for complementary investigations such as evaluating model convective parameterizations or studying the role of ocean mesoscale eddies in air–sea interactions and convective organization.  相似文献   

African climate variability in the satellite era     

Mark R. Jury  Emanuel J. Mpeta 《Theoretical and Applied Climatology》2009,98(3-4):279-291

Interannual fluctuations in rainfall and ocean-atmosphere fields over and around Africa were studied in the satellite era of 1979–2007 using singular value decomposition. The leading modes of rainfall variability in GPCP satellite-gauge merged fields include a leading mode over central Africa, two modes of marine origin in the Gulf of Guinea and Eastern Africa, and two sub-tropical modes over the Sahel and Southern Africa. This differs from earlier gauge-based studies that tend to isolate three leading modes over western, eastern, and southern Africa. In the sea-surface temperature, sea-level pressure and upper wind fields, ENSO signals dominate the leading modes. However, for the low-level wind field, a trough circulation over the southeast Atlantic – Kalahari is the leading mode. It demonstrates predictive potential when cross-correlated with rainfall at 6- to 12-month lead time. Based on continuous filtered data, the value of various indices and the predictability of different zones are examined. The Sahel achieves the highest rank followed by the Congo and southern zones in the next tier. The Guinea and East African rains, which peak in the March-to-May season, appear least predictable. The seasonal rainfall is shown to modulate economic growth rate, and multi-variate predictive algorithms are tested at 6-month lead time.  相似文献   

Hydrology of a spring complex, studied by geochemical time-series data, Acquarossa, Switzerland     

Emanuel Mazor  Francois D. Vuataz 《Applied Geochemistry》1990,5(5-6)

A case study of three springs in Switzerland is used to demonstrate the value of geochemical time-series data as a powerful tool to study the dynamics of groundwater systems. Values of repeatedly measured parameters revealed intermixings of two water types: (a) a 29°C water, circulating to a depth of 1100 m and containing approximately 700 mg/l Ca, 2000 mg/l SO₄, 700 mg/l HCO₃, 20 mg/l of Na and Cl, 6 mg/l Fe, at least 47 mg/l SiO₂, and with an isotopic composition of δD = − 73.0‰ and δ¹⁸ O = −10.9‰, and (b) a 12°C or colder water, shallow, and of a post-1953 age, containing 420 mg/l TDI or less, very low in Na and Cl (4 mg/l or less), isotopic values of δD = −71.0‰ and δ¹⁸ O = −10.5‰ and tritium as in recent (post-bomb) precipitation.  相似文献   

Comments on “carbon dioxide and hurricanes: Implications of northern hemispheric warming for Atlantic/Caribbean storms”     

Prof. K. A. Emanuel 《Meteorology and Atmospheric Physics》1991,47(1):83-84

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Studies of ionospheric variations during geomagnetic activities at the low-latitude station, Ile-Ife, Nigeria     

Emmanuel A. Ariyibi  Emanuel O. Joshua  Babatunde A. Rabiu 《Acta Geophysica》2013,61(1):223-239

The dual frequency SCINDA NovAtel GSV 4004B GPS receiver installed at the Ile-Ife (low-latitude station) has been in operation since December 2009. Data records for the year 2010 were processed to obtain Total Electron Content (TEC) and S ₄ index. These were interpreted to analyze the ionospheric condition during low geomagnetic activity period (when Dst is from ?40 to 0 nT) and during geomagnetic storm events (with Dst about ?100 nT). Seasonal variations of the TEC and S ₄ index were also investigated. The occurrence of scintillations is closely linked to the peak value of TEC during the daytime; this is very evident during the equinox months when TEC ≥ 30 TECu. When the maximum TEC value is below 30 TECu, as shown by most of the days in the summer months, the scintillation phenomenon does not occur. During geomagnetic storms, the daytime segment of the TEC plot experiences fluctuations (even bifurcations) in values with the peak TEC value of about 40 TECu. From the interpreted data, the occurrence of geomagnetic storm does not necessarily suggest an increase in the level of scintillations at a low-latitude region. Also, there is a remarkable difference between the IRI 2007 model and the observed TEC values, as the daytime TEC peak differs in magnitude and time of occurrence from the observed TEC.  相似文献