Upper-Level Winds over Southern Ontario: O-QNet Wind Profiler and NARR Comparisons     

Peter A. Taylor  Wensong Weng  Zheng Qi Wang  Mathew Corkum  Khalid Malik  Shama Sharma 《大气与海洋》2017,55(1):1-11

Upper-level winds are primarily measured by tracking the position of radiosonde balloons as they rise through the atmosphere. Radiosondes are released from a global network at 0000 utc and 1200 utc each day, and data are quickly available to the world's weather services, as well as to the public. The network is relatively coarse spatially, and there are normally only two soundings per day. In an endeavour to provide better spatial and temporal upper-level regional wind measurements, the O-QNet (a demonstration very high frequency wind profiler network for Ontario and Quebec) was installed and has been operated by York, Western, and McGill Universities with support from Mardoc Inc., The Weather Network, and Environment and Climate Change Canada. Initial funding was provided by the Canada Foundation for Innovation, the Ontario Innovation Trust, and Mardoc Inc. The present paper reports primarily on comparisons between winds measured by the O-QNet profilers and the winds reported in the North American Regional Reanalysis (NARR). There is good agreement between the two, which provides support for the use of NARR data to investigate longer term variations in upper-level winds associated with climate change for this region.  相似文献   

Behavior of Fiber Glass Bolts,Rock Bolts and Cable Bolts in Shear     

Xuwei Li  Naj Aziz  Ali Mirzaghorbanali  Jan Nemcik 《Rock Mechanics and Rock Engineering》2016,49(7):2723-2735

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Calcareous nannofossil biostratigraphy and paleoecology of the Cenomanian – Turonian transition in the Tarfaya Basin, southern Morocco     

Abdel Aziz Tantawy   《Cretaceous Research》2008,29(5-6):995

An abundant and diverse nannoflora occurs across the Cenomanian/Turonian (C/T) boundary at Tazra in the Tarfaya Basin of southern Morocco. The nannoflora of this sequence permits recognition of three biozones (CC10-CC12), three subzones (CC10a, CC10b and CC10c), and thirteen important nannolith bioevents previously reported from this interval elsewhere. The floral record shows erratic species abundance fluctuations that clearly vary with lithology and reflect at least in part preservational bias and diagenetic processes. In general, four dissolution resistant taxa are dominant: Watznaueria barnesae, Eiffellithus turriseiffelii, Eprolithus floralis, and Zeugrhabdotus spp. The late Cenomanian Zone CC10 marks a rapid excursion in ∂¹³C and is characterized by the successive extinction of four taxa, which are widely recognized as reliable biomarkers: Corollithion kennedyi, Axopodorhabdus albianus, Lithraphidites acutus, and Helenea chiastia. This interval is also marked by high species richness and high abundance of the tropical species Watznaueria barnesae, suggesting warm tropical waters. The subsequent ∂¹³C plateau and organic carbon-rich black shale deposition of the oceanic anoxic event (OAE2) is characterized by low species richness, but high nannofossil abundance, and peak abundance of the cool water and high productivity indicator Zeugrhabdotus spp., followed by the first peak abundance of cool water Eprolithus floralis. This interval correlates with the planktic foraminiferal diversity minimum and the Heterohelix shift, which marks the expansion of the oxygen minimum zone (OMZ). The C/T boundary is identified based on the FO of Quadrum gartneri, which is <1 m below the FO of the planktic foraminifer C/T marker Helvetoglobotruncana helvetica. In the early and middle Turonian, the two dominant species, tropical W. barnesae and cool water E. floralis, alternate in abundance and suggest fluctuating climatic conditions.  相似文献   

Integrated stratigraphy and <Superscript>40</Superscript>Ar/<Superscript>39</Superscript>Ar chronology of the Early to Middle Miocene Upper Freshwater Molasse in eastern Bavaria (Germany)     

H. Abdul Aziz  M. Böhme  A. Rocholl  A. Zwing  J. Prieto  J. R. Wijbrans  K. Heissig  V. Bachtadse 《International Journal of Earth Sciences》2008,97(1):115-134

A detailed integrated stratigraphic study was carried out on middle Miocene fluvial successions of the Upper Freshwater Molasse (OSM) from the North Alpine Foreland Basin, in eastern Bavaria, Germany. The biostratigraphic investigations yielded six new localities thereby refining the OSM biostratigraphy for units C to E (sensu; Heissig, Actes du Congres BiochroM’97. Mem Trav EPHE, Inst Montpellier 21, 1997) and further improving biostratigraphic correlations between the different sections throughout eastern Bavaria. Radioisotopic ages of 14.55 ± 0.19 and 14.88 ± 0.11 Ma have been obtained for glass shards from the main bentonite horizon and the Ries impactite: two important stratigraphic marker beds used for confirming our magnetostratigraphic calibration to the Astronomical Tuned Neogene Time Scale (ATNTS04; Lourens et al. in Geologic Time Scale 2004, Cambridge University Press, 2004). Paleomagnetic analysis was performed using alternating field (AF) and thermal (TH) demagnetization methods. The AF method revealed both normal and reverse polarities but proofs to yield unreliable ChRM directions for the Puttenhausen section. Using the biostratigraphic information and radioisotopic ages, the magnetostratigraphic records of the different sections are tentatively correlated to the Astronomical Tuned Neogene Time Scale (ATNTS04; Lourens et al. in Geologic Time Scale 2004, Cambridge University Press, 2004). This correlation implies that the main bentonite horizon coincides to chron C5ADn, which is corroborated by its radioisotopic age of 14.55 Ma, whereas the new fossil locality Furth 460, belonging to OSM unit E, probably correlates to chron C5Bn.1r. The latter correlation agrees well with the Swiss Molasse locality Frohberg. Correlations of the older sections are not straightforward. The Brock horizon, which comprises limestone ejecta from the Ries impact, possibly correlates to C5ADr (14.581–14.784 Ma), implying that, although within error, the radioisotopic age of 14.88 ± 0.11 Ma is somewhat too old. The fossil localities in Puttenhausen, belonging to the older part of OSM unit C, probably coincide with chron C5Cn.2n or older, which is older than the correlations established for the Swiss Molasse. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.  相似文献   

塔克拉玛干沙漠不同区域土壤热通量变化比较     

张文斌  买买提艾力﹒买买提依明  何清  杨兴华  霍文  杨帆  塔伊尔.艾则孜 《沙漠与绿洲气象(新疆气象)》2016,10(2):57-62

选取塔克拉玛干沙漠腹地塔中地区和北缘过渡带肖塘地区2013年土壤热通量观测资料,初步比较分析了塔克拉玛干沙漠两种下垫面的土壤热通量变化特征。结果表明：(1)在日变化尺度上,两个站点都有明显的日变化特征,1月份塔中站土壤热通量日平均变化幅度小于肖塘站,日较差分别为58.9 W.m2和72.4 W.m2,4月份两站土壤热通量变化幅度较为接近,日较差分别为88.1W.m2、100.1 W.m2。7、10月份塔中站土壤热通量变化幅度明显高于肖塘站,日较差分别为99.0 W.m2、53.7W.m2,100.3 W.m2、73.3W.m2。(2)不同天气条件下两个站点土壤热通量变化都有很大差异。晴天,塔中站和肖塘站土壤热通量变化都呈现出单峰型,变化幅度较一致,日较差分别为119.7 W.m2、119.1 W.m2。沙尘天和雨天受云层或降水的影响土壤热通量变化波动较大,沙尘天塔中站变化幅度小于肖塘站,日较差分别为83.6 W.m2、133.1 W.m2;雨天塔中站和肖塘站变化幅度都很剧烈,日较差分别为70.6 W.m2、66.6 W.m2。(3)年变化尺度上,塔中站土壤热通量在7月份达到最大值(7.7 W.m2),在11月出现最小值(-5.3 W.m2),肖塘站7月份出现最大值(4.2 W.m2),11月份出现最小值(-10.2 W.m2)。塔中站和肖塘站土壤热通量年总量差异很大,塔中站为16.8 W.m2,能量由大气向土壤传递,土壤为热汇,而肖塘站则为-34.9 W.m2,能量由土壤向大气传播,土壤表现为热源。  相似文献   

Hunza river watershed landslide and related features inventory mapping     

M. Farooq Ahmed  J. David Rogers  Muhammad Zubair Abu Bakar 《Environmental Earth Sciences》2016,75(6):523

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Subsurface profile interpretation of landslides,examples from Bashilo River watershed,Ethiopia     

Elamin H. Ismail  J. David Rogers  M. Farooq Ahmed  M. Zubair Abu Bakar 《Environmental Earth Sciences》2016,75(16):1153

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Development of calcrete of the Late Cretaceous carbonate platform,northern Jordan,and its tectonic implications     

Abdulkader M. Abed  Saja Abu Taha  Tasneem H. Hiasat  Abdalla Abu Hamad 《Arabian Journal of Geosciences》2016,9(11):587

A calcrete horizon, 3–10 m thick, is found exposed in northern Jordan in three localities, Rumman, Marsa’, and Wasfi At Tal forest (WTF). It is situated at the base of the dominantly limestone, Late Cenomanian Hummar Formation, separating it from the underlying marly Fuheis Formation. The calcrete horizon exhibits all the diagnostic features characteristic of calcrete, such as diagenetic pisoids; a mottled or clotted texture; circumgranular cracks around grains in a nodular texture; pendant or microstalactitic cement; meniscus cement; plant roots or rhizogenic structures, both longitudinal and transverse; exfoliation on boulder and cobbles; alagally laminated hard pans; and abundant dissolution of cracks and vugs. Consequently, it represents a subaerial erosional unconformity and type 1 sequence boundary (SB) that was not previously noticed. The Hummar Formation is considered as a third-order sequence with the SB at the base of the calcrete horizon, while the calcrete horizon itself forms the lowstand system tracts (LST). The transgressive systems tracts (TST) involve the lower two third of the Hummar Formation ending with peloidal grainstone representing the maximum flooding surface (MFSs). The rest of the formation is the falling highstand systems tracts (HST). The next SB is not seen due to a thick soil-covered gap. The calcrete horizon formed due to the formation of a paleohigh, in the study area, associated with the compression produced by the initial subduction of the Afro-Arabian Plate under the Eurasian Plate during the Late Cenomanian, slightly earlier than the previously known Turonian subduction and compression.  相似文献   

Speaking of the devil: a systematic literature review on community preparedness for earthquakes     

Shaffril  Hayrol Azril Mohamed  Samah  Asnarulkhadi Abu  Kamarudin  Syafila 《Natural Hazards》2021,108(3):2393-2419

Natural Hazards - Community preparedness in facing natural hazards such as earthquakes is extremely important. Although there are numerous studies on community preparedness for earthquakes, the...  相似文献   

Chitosan – A Sizing Agent in Fabric Production – Development and Ecological Evaluation     

Thomas Stegmaier  Werner Wunderlich  Tom Hager  Abu Bakr Siddique  J. Sarsour  Heinrich Planck 《洁净——土壤、空气、水》2008,36(3):279-286

Chitosan, a natural polymer, was investigated as a possible sizing agent in fabric production by appropriate modification in the textile industry. Based on recipe developments at a laboratory‐scale, the ecological and economical potential of mainly cotton yarns were demonstrated and developed. Subsequent tests within the scope of industrial production confirmed the findings of the basic developments. As an interesting alternative to the conventional sizing process involving the removal of the size after weaving, the use of appropriate processing technologies makes it possible to apply chitosan in the form of a sizing agent resistant to wash‐out processes. Therefore, the wash‐out process and the combined wastewater loading can be avoided and the properties of chitosan can be used beneficially in the later applications of the fabric. The traditional method of sizing and weaving developments as well as the analyses of material recycling showed the possibilities of using closed circuits in textile production involving sizing agent and water. It is possible that a chitosan‐specific enzyme suitable for production conditions, which facilitates the wash‐out process in combination with the biodegradation of the wastewater in a sewage plant, could be developed.  相似文献