Doppler sounder observations of trade winds and sea breezes along the African west coast near 34 ° S, 19 ° E     

Mark Jury  Garth Spencer-Smith 《Boundary-Layer Meteorology》1988,44(4):373-405

Summer weather conditions along the west coast of Africa near 34 ° S, 18 ° E are investigated using doppler acoustic sounder profiles. Case studies were selected from a two-year record to form composite analyses over the diurnal cycle. The SE trade wind exhibited a low level jet at the level of the temperature inversion due to a sharp reversal in the thermal wind vector aloft. Mean wind speeds reached 14 m s^–1 just before midnight as the surface and upper inversions strengthened. Seabreezes were categorised by the supporting gradient wind and found to have mean depths of 400 m, speeds of over 6 m s^–1 at the 200 m level, and advance/retreat times of 09 hr and 16–20 hr. During seabreezes and weak on-shore gradient flow conditions, the thermal internal boundary layer (TIBL) was monitored with sounder transects in the first 12 km of the coastal zone. The growth height was observed to be 1:20 in the first 5 km and 1:50 farther inland. The sounder climatology, together with surface network and aerial survey results, illustrate the four-dimensional characteristics of trade winds and seabreezes near Cape Town.  相似文献   

Landlords and Lodgers: Socio-Spatial Organization in an Accra Community by Deborah Pellow     

Garth Myers 《The Professional geographer》2007,59(1):149-151

  相似文献   

Fisheries in upwelling regions — with special reference to peruvian waters     

Garth I. Murphy 《Geoforum》1972,3(3):63-71

The anchovy population that is the basis of the Peru fishery, the world's largest, is a phytoplankton feeding species, supported by an upwelling based ecosystem. The fish is very short-lived and grows rapidly — both criteria for high turnover rate — high yield fisheries. The maximum sustainable yield is around 10 million metric tons. Analysis of the dynamics of the fishery suggests that the fleet is overbuilt, applying too much fishing effort, and slightly overfishing the population. In consequence, the population may be approaching a size and stress level at which it will be unstable.  相似文献   

Framboidal pyrite associated with lead-zinc mineralisation in mid-Wales     

J. Garth Raybould 《Lithos》1973,6(2):175-181

Framboidal pyrite occurs in the breccia fragments of country rock found in lead-zinc veins, while it is generally absent from unmineralised rocks. It is thought to be cogenetic with the main mineralisation, representing an early stage of deposition.  相似文献   

The unusual and large drawdown response of buried-valley aquifers to pumping     

van der Kamp G  Maathuis H 《Ground water》2012,50(2):207-215

The buried-valley aquifers that are common in the glacial deposits of the northern hemisphere are a typical case of the strip aquifers that occur in many parts of the world. Pumping from a narrow strip aquifer leads to much greater drawdown and much more distant drawdown effects then would occur in a sheet aquifer with a similar transmissivity and storage coefficient. Widely used theories for radial flow to wells, such as the Theis equation, are not appropriate for narrow strip aquifers. Previously published theory for flow to wells in semiconfined strip aquifers is reviewed and a practical format of the type curves for pumping-test analysis is described. The drawdown response of strip aquifers to pumping tests is distinctive, especially for observation wells near the pumped well. A case study is presented, based on extensive pumping test experience for the Estevan Valley Aquifer in southern Saskatchewan, Canada. Evaluation of groundwater resources in such buried-valley aquifers needs to take into account the unusually large drawdowns in response to pumping.  相似文献   

Ashley Dene: Lincoln University Farm: the first 100 years edited by Dick Lucas , Neil Gow and Alistair Nicol (eds), Lincoln University,Canterbury, 2012. 146 pp. ISBN 978‐0‐86476‐250‐4.     

Garth Cant 《New Zealand geographer》2013,69(1):81-82

  相似文献   

Southern African Prehistory and Paleoenvironments, 1984, Richard G. Klein,Editor, A. A. Balkema Publishers, $24.00     

C. Garth Sampson 《Geoarchaeology》1987,2(1):71-73

  相似文献   

The Fill–Spill Hydrology of Prairie Wetland Complexes during Drought and Deluge     

Dean A. Shaw  Garth Vanderkamp  F. Malcolm Conly  Al Pietroniro  Lawrence Martz 《水文研究》2012,26(20):3147-3156

The fill–spill of surface depressions (wetlands) results in intermittent surface water connectivity between wetlands in the prairie wetland region of North America. Dynamic connectivity between wetlands results in dynamic contributing areas for runoff. However, the effect of fill–spill and the resultant variable or dynamic basin contributing area has largely been disregarded in the hydrological community. Long‐term field observations recorded at the St. Denis National Wildlife Area, Saskatchewan, allow fill–spill in the basin to be identified and quantified. Along with historical water‐level observations dating back to 1968, recent data collected for the basin include snow surveys, surface water survey and production of a light detection and ranging–derived digital elevation model. Data collection for the basin includes both wet and dry antecedent basin conditions during spring runoff events. A surface water survey at St. Denis in 2006 reveals a disconnected channel network during the spring freshet runoff event. Rather than 100% of the basin contributing runoff to the outlet, which most hydrological models assume, only approximately 39% of the basin contributes to the outlet. Anthropogenic features, such as culverts and roads, were found to influence the extent and spatial distribution of contributing areas in the basin. Historical pond depth records illustrate the effect of antecedent basin conditions on fill–spill and basin contributing area. A large pond at the outlet of the St. Denis basin, which only receives local runoff during dry years when upstream surface storage has not been satisfied, has pond runoff volumes that increase by a factor of 20 or more during wet years when upstream antecedent basin surface storage is satisfied and basin‐wide runoff contributes to the pond. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Automated mapping of land components from digital elevation data     

J. R. Dymond  R. C. Derose  G. R. Harmsworth 《地球表面变化过程与地形》1995,20(2):131-137

An algorithm for automating the mapping of land components from digital elevation data is described. Land components are areas of relatively uniform slope and aspect and often correspond with ridge crests, shoulders, head slopes, back slopes or foot slopes. Aspect regions, which generally span from stream to ridge, are first identified by generalizing an aspect map derived from digital elevation data. The aspect regions are then split successively into land components by grouping pixels above or below an automatically determined contour of elevation or ‘distance from stream’. The contour approximates a slope break. The land components mapped in this way give a complete polygonization of a hilly landscape and are a reasonable approximation of manually mapped land components.  相似文献   

Climate modelling for the nesting scientist     

Garth W. Paltridge 《Climatic change》1979,2(2):163-174

This paper was originally submitted as a background essay to an early meeting concerned with the development of the GARP Climate Dynamics Sub-Programme. It was an attempt to put the scientific problems into a context which, for the benefit of administrators, leads to a fairly natural structuring of relevant research activity. In its specific references to GARP, the essay has been somewhat overtaken by events - but the concepts are still relevant at this time when it remains unclear as to how the climate problem is to be solved.

---

  相似文献