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ANDREW RUSSELL GERAINT VAUGHAN EMILY G. NORTON HUGO M. A. RICKETTS CYRIL J. MORCRETTE TIM J. HEWISON KEITH. A. BROWNING ALAN M. BLYTH 《地球,A辑:动力气象学与海洋学》2009,61(2):250-263
A narrow line of convective showers was observed over southern England on 18 July 2005 during the Convective Storm Initiation Project (CSIP). The showers formed behind a cold front (CF), beneath two apparently descending dry layers (i.e. sloping so that they descended relative to the instruments observing them). The lowermost dry layer was associated with a tropopause fold from a depression, which formed 2 d earlier from a breaking Rossby wave, located northwest of the UK. The uppermost dry layer had fragmented from the original streamer due to rotation around the depression (This rotation was also responsible for the observations of apparent descent—ascent would otherwise be seen behind a CF). The lowermost dry layer descended over the UK and overran higher θ w air beneath it, resulting in potential instability. Combined with a surface convergence line (which triggered the convection but had less impact on the convective available potential energy than the potential instability), convection was forced up to 5.5 km where the uppermost dry layer capped it. The period when convection was possible was very short, thus explaining the narrowness of the shower band. Convective Storm Initiation Project observations and model data are presented to illustrate the unique processes in this case. 相似文献
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HUGO MINELL 《Boreas: An International Journal of Quaternary Research》1980,9(4):275-281
An inventory of bedrock material has been made from different levels in some moraine types situated in the areas around Storvindeln and Storavan. The results show that moraine forms which have a curved morphology transverse to the direction of ice flow, always have a high content of local bedrock material independent of till thickness. In many cases the local bedrock material is represented more in the upper levels of the moraine. Large transverse ridges with less curvature have a highly variable bedrock content. Drumlins may lack local bedrock material over a distance of many kilometres. The variable distribution of local bedrock material in different moraine types has been interpreted as a function of ice pressure, temperature, and movement during deglaciation. 相似文献
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Dr. HUGO BOYKO 《水文科学杂志》2013,58(2):163-164
SUMMARY The evaporation tank consists of a square pan with a flat base, 2 metres long and 0, 7 metre deep, set into the ground with the rim 0, 1 metre above, and connected to a well on which is installed a limnigraph. This limnigraph records continuously fluctuations of the free water surface. The recordings show that a large amount of water can be evaporated during rainfall. This phenomenon is specific at every evaporation tank with a free water surface. It is only during the dry intervals that a strong correlation can be established between the evaporation measured in the tank and the potential evapotranspiration of the surrounding natural surfaces. In order to locate the dry intervals and to measure the evaporation only during these intervals, it is necessary to use an apparatus provided with a continuous recording mechanism 相似文献
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A second deep Schlumberger sounding has been carried out in South Africa, this time using a newly completed power transmission line, not yet in sevice, as emission line. The maximum current electrode separation attained was 600 km. The sounding was situated on a shield area with a thin cover of sedimentary rocks (Karroo System) overlying the archaean granite. The center was chosen near to the village of Dealesville. It is shown that lateral effects at large AB spacings are unlikely, but due to numerous dolerite intrusions in the sediments surface electrode effects must be guarded against; thus AB positions were chosen by geologists. Because of a low signal/noise ratio at large AB spacings the measurements were treated statistically; in particular, the elimination of non-random events improved the measuring accuracy. Although a thin conducting layer at the base of the sedimentary succession decreased the resolution of the sounding curve, the results, which were interpreted with the aid of a computer, show positively that
- (a). the crust is multi-layered with a highly resistant portion having a minimum resistivity of 15000 ohm.m and
- (b). a good, thick conductor appears as the final layer.
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GRAEME HUGO 《New Zealand geographer》1999,55(2):25-35
New Zealand origin academics have played a key role in the academic study of Australia's population in the post-war period. The paper argues that New Zealanders have contributed not only to the furthering of knowledge of the processes of change in the Australian population but have been important in the teaching of population geography in Australian universities, made inputs into policy relating to population and been influential in the development of the Australian Population Association. Major contributions have been made by New Zealanders not only in the traditionally strong areas of population geography such as internal and international migration but also in the areas of fertility, mortality and ageing. 相似文献
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GERLACH DAVID C.; FREY FREDERICK A.; MORENO-ROA HUGO; LOPEZ-ESCOBAR LEOPOLDO 《Journal of Petrology》1988,29(2):333-382
Puyehue Volcano (40?5?S) in the southern volcanic zone (33?46?)of the Andes is a largely basaltic stratovolcano constructedon a highly eroded, dominantly andesitic volcanic center. Duringgrowth of Puyehue Volcano there was a trend from basaltic tomore siliceous lavas, and the most recent eruptions (192122,1960) are Cordon Caulle rhyodacites and rhyolites erupted fromfissures northwest of the volcano. These basaltic through rhyoliticlavas define a medium-K2O suite of tholeiitic affinity withtrace element and Pb-isotopic signatures typical of volcanicrocks associated with subduction zones. Most of the evolved lavas, ranging from andesite to rhyolite,formed by low to moderate pressure ( 5 kb) fractional crystallizationof a plagioclase-dominated anhydrous assemblage. Magma mixingproduced aphyric basaltic andesites with anomalously high incompatibleelement contents and latestage andesites with disequilibriumphenocryst assemblages. The age progression from abundant basaltto younger, less voluminous, more silicic lavas reflects increasinglygreater degrees of fractional crystallization which caused theapparent compositional gap between mixing end members to widen. There is no evidence in the silicic lavas for assimilation ofgeochemically distinctive continental crust. Puyehue basaltsare surprisingly more heterogeneous in 87Sr/86Sr (0?703780?70416)and incompatible element abundance ratios (e.g., La/Sm, Ba/Nb)than the more evolved lavas. This geochemical variability mayreflect subcrustal source heterogeneities or contamination bylower crust. The older basaltic andesites and andesites underlyingthe Puyehue edifice have Sr and Nd isotopic ratios and incompatibleelement abundance ratios within the range of Puyehue basalts.Apparently, similar sources and processes were involved in theirgenesis. 相似文献
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