重庆雾的三维数值模拟   总被引：11，自引：3，他引：11  

石春娥  孙学金 《南京气象学院学报》1997,20(3):308-317

利用复杂地形上的三维雾模式模拟了重庆冬季雾的形成、发展及演变过程，模拟结果与实况基本吻合。一系列敏感性数值试验的结果使我们对重庆雾的影响因子有了进一步的了解。  相似文献   

长江三峡坝区的大雾分析   总被引：2，自引：2，他引：2       下载免费PDF全文

陈乾金  江滢  王丽华 《气象》1997,23(6):28-32

利用宜昌站长年资料序列，分析了三峡坝区大雾的基本特征，并讨论了三峡大坝流期的最佳保证率，为三峡大坝工程提供参考资料。  相似文献   

云南安宁市辐射雾大气扩散参数研究          下载免费PDF全文

沈鹰 《气象》1997,23(7):29-31

利用三向风标探测资料，分析了安宁县辐射雾中的扩散参数，结果表明：平均风速对水平风向脉动标准差起着重要作用，是影响水平湍流扩散的关键因子；雾中的横向和铅直方向扩散参数分别相当于ＰａｓｑｕｉｌｌＢ类和Ｄ类稳定度下的扩散参数，表明在辐射雾出现期间，虽然铅直方向上的扩散能力不强，但有较强的水平扩散能力。  相似文献   

城市化对西双版纳辐射雾的影响   总被引：11，自引：10，他引：11  

黄玉仁  沈鹰  黄玉生  谭应中 《高原气象》2001,20(2):186-190

利用景洪气象站和大勐龙气象站的资料，对西双版纳辐射雾减少的原因进行了分析。结果表明：1960－1984年，地形地质条件相近的景洪站与大勐龙站的年雾日数、年均气温、年均湿度、年均最高气温、年均最低气温等气象要素的变化一致，可以认为两站的自然气候变化是一致的。而1985年以后，两站年雾日数和年平均湿度的变化出现较大差异。通过对人文条件的对比发现，景洪市的城市化进程远远大于大勐龙站。因此，我们初步认为城市化对西双版纳辐射雾减少所起的作用远远大于自然气候变化和森林砍伐的作用。  相似文献   

The role of dew as a moisture source for sand microbiotic crusts in the Negev Desert, Israel   总被引：2，自引：0，他引：2  

Giora J. Kidron  Ilana Herrnstadt  Eldad Barzilay 《Journal of Arid Environments》2002,52(4):517

Dew and fog were measured periodically during the years 1992–1995 at the Hallamish dune field, western Negev Desert (average annual rain precipitation ca. 95 mm). A major portion of the dunes are covered by cyanobacterial and moss-dominated microbiotic crusts. Chlorophyll- a measurements and microscopic examination were carried out in order to detect the possible changes in crust biomass and phenological changes of the mosses following the occurrence of dew and fog. Dew and/or fog were present in over 50% of the late summer and fall mornings with an average yield of 0·1 mm on cloth attached to glass plates. This corresponds to ca. 0·03 mm for the upper 0·5 cm of the crust, and is less than the 0·1 mm threshold which implies liquid water and which was also found necessary for net photosynthesis of the cyanobacterial crust. This threshold was met only during heavy dew or fog events, during which 10–40% of the crust surface area was moistened. It was estimated that dew and fog could account for upto 3·2–9·4% of the total annual time of crust wetness and consequently activity due to liquid water. Nevertheless, microscopic examination of the dominant moss species at Nizzana, Bryum dunense, disclosed phenological changes, mainly resulting in growth of vegetative reproduction organs (bulbils), and sexual organs, gametangia (antheridia and archegonia). B.dunense may thus be adapted to the utilization of dew and fog precipitation for the production of nearly mature sexual organs. The moss may thus be capable of already utilizing the first winter rains for fertilization and sporophyte formation.  相似文献   

黄海沿海夏季海雾形成的气候特征   总被引：18，自引：0，他引：18  

王鑫  黄菲  周琇 《海洋学报》2006,28(1):26-34

采用合成与个例分析相结合的方法,对黄海夏季(7月)海雾形成的大气环流条件、水汽输送条件以及海面条件(SST)进行了分析,并讨论了海面的有效长波辐射,结果表明:夏季风的强弱决定了黄海夏季海雾的多寡,海雾形成的水汽不是由局地提供的,而是靠低空急流从热带大气输送过来.与大气环流条件相配合,海温场对海雾的形成是重要的.  相似文献   

1989年东海陆架水团及高密水环流的季节变化   总被引：3，自引：1，他引：3  

黄树生  潘玉球 《海洋学研究》1997,15(2):46-57

本文利用１９８９年的观测资料，分析了水团及高密水环流的季节演变特征。结果表明：东海高密水在陆架上存在一个季节性的变化过程，核心区有一个气旋型的密度环流；这个环流秋、冬季较弱，春、夏季较强；在该环流的产生过程中，它可以影响邻近水团的分布；在春季，邻近水团在东海高密水周围形成一个环状分布  相似文献   

丹东附近海域海雾的特征及其海洋、大气背景条件分析   总被引：1，自引：0，他引：1  

孙连强  曹士民  柳淑萍  高松影  王文武 《海洋预报》2006,23(3):22-29

使用常规气象观测资料、NOAA-17及EOS/MODIS卫星遥感影像资料分析了37个海雾个例,揭示了丹东附近海域海雾的统计规律和海雾形成的大气、海洋背景条件。  相似文献   

关于海雾生成的探讨   总被引：3，自引：0，他引：3  

陈绍鑫  常美桂  曲维政  徐静琦  胡基福  赵松鹤  张正 《中国海洋大学学报(自然科学版)》1994,(3)

分析海上雷达波的超折射现象，指出：海雾的出现总是在雷达波发生超折射之后，由此确定海雾形成时的大气结构特征，并对海雾的生成以及其出现时间有了新的了解。指出根据雷达波超折射现象可用来作海雾预报。  相似文献   

New Development of Eastern Mediterranean Circulation based on Hydrological Observations and Current Measurements   总被引：2，自引：0，他引：2  

Beniamino B. Manca  Laura Ursella  Paolo Scarazzato 《Marine Ecology》2002,23(S1):237-257

Abstract. A number of recent studies based on hydrographic observations and modelling simulations have dealt with the major climatic shift that occurred in the deep circulation of the Eastern Mediterranean. This work presents hydrographic observations and current measurements conducted from 1997 to 1999, which reveal strong modifications in the dynamics of the upper, intermediate and deep layers, as well as an evolution of the thermohaline characteristics of the deep Aegean outflow since 1995. The reversal of the circulation in the upper layer of the north/central Ionian is worthy of note. The observations indicate a reduction of Atlantic Water in the northern Ionian with an increase on the eastern side of the basin. In the intermediate layer, the dispersal path of the Levantine Intermediate Water (LIW) is altered. Highly saline (>39.0) and well-oxygenated intermediate waters were found near the Western Cretan Arc Straits. They flow out from the Aegean, thus interrupting the traditional path of the LIW, and spread prevalently northwards into the Adriatic Sea. In the deep layer, dense waters, exiting from the Adriatic (σ_ø−29.18 kg · m⁻³), flow against the western continental margin in the Ionian Sea at a depth of between 1000–1500 m. Dense waters of Aegean origin (> 29.20 kg · m⁻³), discharged into the central region of the Eastern Mediterranean during the early stages of the transient, propagate prevalently to the east in the Levantine basin and to the west in the northern Ionian Sea. Near-bottom current measurements conducted in the Ionian Sea reveal unforeseen aspects of deep dynamics, suggesting a new configuration of the internal thermohaline conveyor belt of the Eastern Mediterranean.  相似文献