نتایج جستجو برای: natural and anthropogenic sources

تعداد نتایج: 16910230  

Journal: :Science 2013
Logan Mitchell Ed Brook James E Lee Christo Buizert Todd Sowers

The origin of the late preindustrial Holocene (LPIH) increase in atmospheric methane concentrations has been much debated. Hypotheses invoking changes in solely anthropogenic sources or solely natural sources have been proposed to explain the increase in concentrations. Here two high-resolution, high-precision ice core methane concentration records from Greenland and Antarctica are presented an...

2010
Paul Ginoux Dmitri Garbuzov Christina Hsu

[1] Mineral dust interacts with radiation and impacts both the regional and global climate. The relative contribution of natural and anthropogenic dust sources, however, remains largely uncertain. Although human activities disturb soils and therefore enhance wind erosion, their contribution to global dust emission has never been directly evaluated because of a lack of data. The retrieval of aer...

Hoda Karimi, Maryam Mohammadi Roozbahani, Rezvan Sorooshnia, Soheil Sobhan Ardakani,

Background: Soil serves as a major reservoir for contaminants as it can bind to various chemicals. The aim of this study was to evaluate the levels of some metals (Cd, Cu, Fe and V) in soil samples collected from different stations of Ahvaz Industrial Complex II to determine the natural and anthropogenic contribution of metal in the soil. Methods: This was an experimental study that carried ou...

2016
Luke Bridgestock Tina van de Flierdt Mark Rehkämper Maxence Paul Rob Middag Angela Milne Maeve C Lohan Alex R Baker Rosie Chance Roulin Khondoker Stanislav Strekopytov Emma Humphreys-Williams Eric P Achterberg Micha J A Rijkenberg Loes J A Gerringa Hein J W de Baar

Anthropogenic emissions completely overwhelmed natural marine lead (Pb) sources during the past century, predominantly due to leaded petrol usage. Here, based on Pb isotope measurements, we reassess the importance of natural and anthropogenic Pb sources to the tropical North Atlantic following the nearly complete global cessation of leaded petrol use. Significant proportions of up to 30-50% of ...

Journal: :The Science of the total environment 2015
P A Auger E Machu T Gorgues N Grima M Waeles

A Lagrangian approach based on a physical-biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the North-West African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is prov...

2012
Paul Ginoux Joseph M. Prospero Thomas E. Gill N. Christina Hsu Ming Zhao

[1] Our understanding of the global dust cycle is limited by a dearth of information about dust sources, especially small-scale features which could account for a large fraction of global emissions. Here we present a global-scale highresolution (0.1 ) mapping of sources based on Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue estimates of dust optical depth in conjunction with o...

Journal: :iranian journal of toxicology 0
maryam mohammadi roozbahani department of the environment, ahvaz branch, islamic azad university, ahvaz, iran soheil sobhan ardakani department of the environment, hamedan branch, islamic azad university, hamedan, iran hoda karimi msc graduated in environmental sciences, young researchers & elite club, ahvaz branch, islamic azad university, ahvaz, iran rezvan sorooshnia msc graduated in environmental sciences, young researchers & elite club, ahvaz branch, islamic azad university, ahvaz, iran

background: soil serves as a major reservoir for contaminants as it can bind to various chemicals. the aim of this study was to evaluate the levels of some metals (cd, cu, fe and v) in soil samples collected from different stations of ahvaz industrial complex ii to determine the natural and anthropogenic contribution of metal in the soil. methods: this was an experimental study that carried out...

Journal: :Water 2023

Two rivers from Taiwan with different source inputs, the Danshuei (polluted) and Liwu (non-polluted), were selected to study behavior of molybdenum (Mo) isotopes during weathering riverine transport. In River, δ98/95Mo ranges 0.83‰ 1.50‰ (wet season) 0.54‰ 1.25‰ (dry season). With a few exceptions, in River is lighter wet season, while, contrast, heavier dry season. varies 1.30‰ gets along main...

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