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Résultats de la recherche (686 résultats)

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  • External supply of dust in the Taklamakan sand sea, Northwest China, reveals the dust-forming processes of the modern sand sea surface
  • Aeolian dust ; Aeolian features ; Aeolian transport ; Arid area ; China ; Dust storm ; Geochemistry ; Grain size distribution ; Rare earth elements ; Xinjiang
  • The AA. investigated dust fallout characteristics at a height of 3 m and rare earth element (REE) geochemistry of different landforms in the Taklamakan sand sea, which has frequent dust events. The seasonal fallout and concentrations of PM10
  • particles and monitoring results of their land surface concentrations show that the Taklamakan sand sea is surrounded by dust sources, and it's an important dust deposit area. The particle size characteristics of dust sediment suggest that the dust-conveying
  • capacity of the Taklamakan sand sea is much stronger than that of the Gobi and degraded surfaces on the sand sea edge. It is highlighted that the areas surrounding Taklamakan sand sea are the main dust source areas. Taklamakan sand sea is also an important
  • source of reworked dust.
  • Meteorological and environmental aspects of dust storms in Northern Mexico
  • A geography of dust storms in south-west Asia
  • Recent advances in our understanding of dust source emission processes
  • Aeolian features ; Aeolian transport ; Aerosol ; Bibliography ; Climate ; Dust storm ; Impact ; Land atmosphere interaction ; Model ; Remote sensing ; Scale ; The 2000's
  • from specific landforms, and the use of remote sensing data to reconcile dust storm inventories by direct comparison to dust source geomorphology. These case studies highlight significant advances in both field measurement and regional understanding
  • This review provides a critical overview of recent studies of aeolian processes from within or on dust sources, and focuses on studies dealing with retrieval of dust emission data, quantification of the contribution and variability of dust emissions
  • of important components of the dust cycle derived through use of remote sensing data. However, for strategies aimed at inclusion of dust emission schemes at a scale relevant to climate models, additional research is needed to increase the quantification
  • of a wider range of dust source types and geomorphological contexts over longer time periods.
  • Dust emission in northern China : atmospheric emission–dispersion modelling of a major dust event
  • Aeolian features ; China ; Desert ; Dust storm ; Inner Mongolia ; Model ; Numerical model ; Remote sensing
  • the dust emission model DUSTEM, and the transport model CAMx. The performance of the three-model simulation system was evaluated using a major dust storm that occurred in March 2002 in the desert of the Alashan Prefecture (Inner Mongolia, China) and which
  • in the modelling system. Simulated dust storm features, from the higher resolution grid, are in good agreement with observed data. This integrated numerical model, along with the remote sensed land surface characterization, is suggested to be a practical
  • and flexible tool for simulating and analysing the whole dust storm dynamics.
  • The AA. propose a simulation system that integrates 3 different models in order to represent the whole dust cycle. The RAMS atmospheric model configuration has 2 nested grids, at 50 km and 10 km horizontal resolution, and is used to force both
  • had a significant impact over a large area in northern China. In order to identify potential active dust sources, a specific remote sensed analysis, calibrated through a field campaign in the Alashan Prefecture region, has been assimilated
  • Accumulation of Asian long-range eolian dust in Japan and Korea from the Late Pleistocene to the Holocene
  • Atmospheric circulation ; China ; Dust storm ; Eolian dust ; Eolian features ; Eolian transport ; Geochemistry ; Geochronology ; Isotope analysis ; Japan ; Loess ; Mineralogy ; Oxygen 18 ; Palaeosol ; Pedogenesis ; Quaternary ; Remote sensing
  • The physical, chemical, mineralogical and geochemical characteristics of Asian long-range eolian dust, the dust flux in the Late Pleistocene and the Holocene, and the implications of Asian long-range eolian dust in terrestrial and atmospheric
  • Temporal and spatial aspects of blowing dust in the Mojave and Colorado deserts of southern California, 1973-1994
  • Arid area ; Atmospheric dynamics ; California ; Colorado ; Desert ; Dust storm ; Seasonality ; Spatial variation ; Statistics ; United States of America ; Wind ; Wind erosion
  • Dust events in the Mojave Desert characteristically occur during the winter to spring months (February-May), associated with dry frontal activity, and are largely absent during the dry summer months. The Colorado Desert experiences a similar
  • seasonal distribution of dust events, but has more summer events, usually associated with convective thunderstorms. Frequencies of blowing dust have weak, but statistically significant, correlations with mean annual and antecedent precipitation, suggesting
  • that complex processes control dust emission.
  • Aeolian features ; Aeolian transport ; Arid area ; China ; Climatic change ; Dune ; Dust storm ; Geochemistry ; Grain size distribution ; Inner Mongolia ; Microstructure ; Oasis
  • be identified. The Ejin Section has recorded the repeated dust-storms or sandstorms since 2500 yr BP and these peak periods are consistent with the records of dust rains in historical literatures, indicating that the change of climate is a key factor to increase
  • sandstorms or dust-storms, whreas, artificial factor may only be an accelerating one for desertification.
  • Magnitude and frequency of blowing dust on the Southern High Plains of the United States
  • Aeolian features ; Atmospheric circulation ; Dust storm ; New Mexico ; Plant cover ; Soil erosion ; Statistics ; Texas ; United States of America ; Wind erosion ; Wind speed
  • The purpose of this study is to gain an appreciation of the relative roles of large, moderate, and small blowing-dust events on the Southern High Plains. In the absence of detailed quantitative data on these events during the 1930s, the AA. focus
  • Calibration of GOES-VISSR, visible-band satellite data and its application to the analysis of a dust storm at Owens Lake, California
  • Aeolian features ; Aerosol ; California ; Data processing ; Dust storm ; LANDSAT ; Lake ; MSS ; Remote sensing ; Salt ; United States of America ; Wind erosion
  • -received radiances; and incorporates surficial information with the satellite data for better interpretation of the March 11 dust storm.
  • for quantitative analyses on the extent of surface erosion and amount of suspended dust; compares optical and physical properties of the suspended dust measured on the ground to those properties derived from a radiative transfer model applied to the satellite
  • Recent African dust deposition in West Germany―Sediment characteristics and climatological aspects
  • Aerosol ; Africa ; Atmospheric circulation ; Clay mineral ; Dust storm ; Eolian dust ; Eolian features ; Eolian transport ; Germany ; Grain size distribution;Granulometry ; Mineralogy ; Sahara ; Sahel
  • During the observation period from October 1987 to April 1989 nine deposition events of African mineral dust were recorded in Bochum, West Germany. This paper describes sedimentary characteristics of the fallout material and discusses critical
  • climatological aspects of African dust deposition in Europe.
  • Spatio-temporal distribution of dust storms - a global coverage using NASA TOMS aerosol measurements
  • Aeolian features ; Aerosol ; Arid area ; Atmospheric circulation ; Dust storm ; Remote sensing ; Seasonality ; Semi-arid area ; Space time ; Spatial distribution ; Thematic map
  • Geographical distributions and seasonality patterns of major dust source areas were analysed in the paper by using the daily aerosol measurements of NASA’s Total Ozone Mapping Spectrometer (TOMS) between 1979 and 2011. Spatial investigations
  • of aerosol maps have confirmed that major source areas can be connected to specific geomorphological environments of distinct arid-semiarid regions with recent pluvial history. Largest dust activity can be observed in the topographical lows of Saharan
  • and Arabian deserts, and in the intermountain, endorheic basins of Central Asia fed by fine-grained material from the adjacent mountain belts. Dust emissions are associated to regional seasonal, meteorological conditions; with typically high dust activity
  • Aeolian features ; Aeolian transport ; Cultivated land ; Dust storm ; Grain size distribution ; Sedimentology ; Soil erosion ; Texas ; United States of America ; Wind erosion
  • The objectives of this research were to investigate through field measurements the vertical distribution of eroded soil materials above eroded farmland during sand-dust storms, including consideration of mass flux and grain-size parameters
  • . This paper reports the results of an examination of the grain-size distribution in a sandy loam soil in Big Spring, Texas, during sand-dust storms in the 1995 wind-erosion season.
  • Aeolian dust ; Aeolian features ; Arid area ; Bibliography ; Desert ; Geochemistry ; Geomorphology ; Hydrology ; Palaeo-environment ; Quaternary ; Weathering
  • Over 200 articles are reviewed here. Work, on aeolian processes has continued to dominate, especially research into the origins and implications of dust storms, but there have also been major advances in our understanding of desert hydrological
  • Saltating particles, playa crusts and dust aerosols at Owens (dry) Lake, California
  • Aeolian features ; Aeolian transport ; Aerosol ; Arid area ; California ; Duricrust ; Dust storm ; Lake ; United States of America ; Wind erosion
  • The AA. have studied the generation of dust storms on the south sand sheet of Owens (dry) Lake, an anthropogenically dessicated playa reported to be the single greatest source of particulate matter in North America. During March 1993, they performed
  • an intensive field study including 8 significant dust storms. They studied sources and magnitude of coarse saltating particles, the meteorological conditions that allow them to become mobile, and how the motion of saltating particles across different types
  • of playa surfaces results in the generation of PM10 dusts (aerosol particles smaller than 10 μm aerodynamic diameter).
  • Dust storms and related phenomena measured from meteorological records in Australia
  • The relationship of weather types to dust storm generation in Arizona (1965-1980)
  • Dust storms in space and time
  • Aeolian features ; Aeolian transport ; Arid area ; China ; Dust storm ; Grassland ; Impact ; Inner Mongolia ; Over-grazing ; Semi-arid area ; Vegetation ; Wind erosion
  • Wind erosion and dust storms are common phenomena in the semi-arid Xilingele grassland (Inner Mongolia) and contribute considerably to matter balances. Based on wind erosion measurements in spring 2005 and 2006 the organic carbon and total nitrogen
  • . The 2 years of measurement show the high annual variability of dust storm processes. This variability shows that single very strong events can determine the net balance of a whole year.
  • contents of dust were analyzed to determine the contribution of wind erosion processes on C- and N-ratios to the grasslands. The great range of dust emission and deposition at the different grazing intensities underlines the sensibility of the grassland
  • Relationships among dust outbreaks, vegetation cover, and surface soil water content on the Loess Plateau of China, 1999-2000
  • Aeolian features ; China ; Dust storm ; Loess ; Model ; Natural hazards ; Plant canopy ; Plateau ; Preventive measure ; Soil water ; Threshold ; Vegetation index ; Wind speed
  • Here the AA. examined to detect the effect of vegetation cover and surface soil water content on dust outbreaks by using weather reports from 1999 and 2000 when dust outbreak frequency was low and high respectively. This study will be useful
  • for preventing dust emission and planning for planting programs on the Loess Plateau; for example, knowing the threshold values of Normalized Difference Vegetation Indices (NDVI) and surface soil water content likely to cause dust events would be helpful given
  • the availability of systems like the Early Warning system for Asian dust.