Simulation of the effect of wind speedup in the formation of transverse dune fields
Aeolian features ; Dune ; Earth surface processes ; Model ; Simulation ; Wind speed
The AA. analyse Werner's dune-field simulation model for the uni-directional wind regime leading to the evolution of transverse dunes. Following this, they introduce 2 revisions to the Werner model, which lead to dunes that more closely resemble
those in nature. The first revision incorporates wind structure over a dune, and the second considers the wind speedup and the equilibrium dune shape.
Aeolian features ; Aeolian transport ; Model ; Numerical model ; Sand ; Simulation ; Wind speed
One-dimensional simulations of the unsteady saltation process show that the transport rate's response depends on the amplitude and frequency of the wind fluctuations. The numerical model presented in this paper is capable of simulating temporal
variations in wind speed. The wind velocity is varied with an unsteady upper boundary condition. The model predicts different transient behaviour for different heights of the simulation, i.e. different wind tunnel heights.
Wind tunnel and field calibration of five aeolian sand traps
Aeolian features ; Aeolian transport ; Experimentation ; Grain size distribution ; Methodology ; Wind speed
The efficiency of 5 aeolian sand samplers was tested via wind tunnel experiments and field measurements : the Big Spring Number Eight (BSNE) sampler, the Modified Wilson and Cooke (MWAC) sampler, the Suspended Sediment Trap (SUSTRA), the Pollet
Experimental study of wind directional variability in the vicinity of a model valley
Aeolian features ; Aeolian transport ; Aerosol ; Atmospheric pollution ; Experimentation ; Modelling ; Topography ; Valley ; Wind ; Wind speed
This paper reports the results of a preliminary study examining the effects of valley presence on airflow direction and focuses on valleys situated in areas of low relief. Wind tunnel experiments are used to visualise near-surface airflow over
Observational study and summertime ice at the Nakayama Wind-Hole in Shimogo, Fukushima
Biogeography ; Ecosystem ; Hokkaido ; Ice ; Japan ; Microclimate ; Nivation hollow ; Permafrost ; Soil temperature ; Summer ; Temperature gradient ; Wind
Nakayama Wind-Hole is an important Natural Monument to be preserved for a rare alpine plant in low altitude which survive under the cold air blowing form the wind hole. For this reason, the AA. have conducted here in situ observation for more than
a year from February 1998 through July 1999. This paper documents the comprehensive observational result for the summertime ice at the Nakayama Wind-Hole. It supports the theory of dynamic thermal filter where only coldness tends to accumulate
The significance of yardangs and ventifacted rock outcrops in the reconstruction of changes in the late Quaternary wind regime in the western desert of Egypt
The significance of yardangs and ventifacted rock outcrops in the reconstruction of changes in the late Quaternary wind regime in the western desert of Egypt
Aeolian features ; Aeolian transport ; Model ; Sedimentology ; Simulation ; Turbulence ; Wind
This report presents a two-dimensional numerical model of the grain-wind interactive process, which was developed out of the existing one-dimensional model by McEwan (McEwan and Willetts, 1993). The computer program was rewritten to simulate
Air temperature ; Baltic Sea ; Carbon dioxide ; Climatic variation ; Coastal environment ; Global change ; Model ; Poland ; Salinity ; Sea level ; Wind ; Wind speed
. These local fields are : wind at coastal stations; the wave field on the southern Baltic; air temperature on the coast; and salinity in the coastal zone. Scenarios concerning the future evolution of the local systems have been developed using results of some
Aeolian features ; Aeolian transport ; California ; Coastal environment ; Dune ; Model ; Seasonal variability ; Sediment transport ; United States of America ; Wind speed
Aeolian sand transport was studied at the Lansphere dunes, a coastal dune complex in northern California, by comparing slipface advance rates with transport predicted based on local wind data. The slipface of a 2.5 m high transverse ridge and 10 m
high parabolic dune were monitored over a period of 3 months, during dry season, to estimate sand discharge. Field measurements were used to generate three-dimensional representations of dune slipfaces. Hourly wind data collected during the same time
Dry aeolian dust accumulation in rocky deserts : a medium-term field experiments based on short-term wind tunnel simulations
The A. explore the possibilities of using short-term wind tunnel simulations for the prediction of medium-term dust accumulation. The pattern of aeolian dust deposition and aeolian dust erosion created on a topographic scale model of a hilly desert
Atmospheric dynamics ; China ; Desertification ; Dust storm ; Environment ; Environmental management ; Human impact ; Impact ; Land use ; Northern China ; Over-grazing ; Wind ; Wind speed
Sandstorm is a frequently occurred disastrous weather in northern China. The increasing occurence frequency recently, especially sandstorms with high intensity in the spring of 2000 have caused great loss to national economy. However
Biogeography ; Climatic index ; Microrelief ; Palsa ; Peat bog ; Periglacial features ; Precipitation ; Sweden ; Temperature ; Wind
with occurrence of palsa-like forms in Sweden at the present time. In spite of a warmer climate towards the latter part of this century, palsa-like features have survived in this area. The palsa formation is probably dependent on strong winds thinning out
Aeolian deflation ; Aeolian features ; Aeolian transport ; Arid area ; China ; Desert ; Dune ; Geomorphometry ; Wind speed ; Xinjiang ; Years 1990-99
as they are generally supposed to be. The advance rate of the dunes was controlled by the local wind regime and dune morphometry. However, the relationships between advance rate and the morphometric parameters of the dunes are variable for the immature dunes.
Air temperature ; Atmospheric circulation ; Central Europe ; Climate ; Europe ; Global change ; Greenhouse effect ; Model ; Ocean circulation ; Poland ; Precipitation ; Simulation ; Temperature ; Twenty-first century ; Wind
, precipitation and wind speed. Control runs of the models for the period 1960-1989 and the results of the Greenhouse Gas plus Sulphate experiment for the next century 2000-2099 have been analysed. Re-analysed observed data have been used as the reference