区域大气环境应急响应数值预报系统

介绍了针对国内有毒气体泄漏等突发性大气中污染物扩散问题建立的区域精细大气环境应急响应数值预报业务系统。该系统基于污染扩散模式HYSPLIT_4,利用中尺度模式WRF为其提供气象场,对污染扩散的路径和浓度以及地面沉降进行计算,系统后端开发了基于GIS的产品制作平台对模式产品进行叠加地理信息的处理。为实现快速应急响应的功能,模式业务系统始终处于热准备状态,并可在接到指令后迅速完成产品制作。文中给出一个大气环境应急响应演习应用实例,显示该模式系统对影响范围较大的有毒气体泄漏事件应急响应工作具备一定的指导意义和应用前景。     

RESEARCH ON AUTOMATIC FOG IDENTIFICATION TECHNOLOGY BY METEOROLOGICAL SATELLITE REMOTE SENSING

There is an urgent need for the development of a method that can undertake rapid, effective, and accurate monitoring and identification of fog by satellite remote sensing, since heavy fog can cause enormous disasters to China’s national economy and people's lives and property in the urban and coastal areas. In this paper, the correlative relationship between the reflectivity of land surface and clouds in different time phases is found, based on the analysis of the radiative and satellite-based spectral characteristics of fog. Through calculation and analyses of the relative variability of the reflectivity in the images, the threshold to identify quasi-fog areas is generated automatically. Furthermore, using the technique of quick image run-length encoding, and in combination with such practical methods as analyzing texture and shape fractures, smoothness, and template characteristics, the automatic identification of fog and fog-cloud separation using meteorological satellite remote sensing images are studied, with good results in application.     

影响卢氏县的气象灾害防御措施

影响卢氏山区的气象灾害有暴雨、暴雪、寒潮、大风、高温、干旱、雷电、冰雹、大雾、道路积冰等.其中暴雨、冰雹出现频率较高,且危害最大.为防御气象灾害,气象部门应提高灾害性天气预报准确率;政府及有关单位要及时把灾害性天气预报信息通过各种渠道,及时传播至千家万户;加强防灾减灾宣传,提高民众自救能力;建立和完善灾害性天气预警应急预案.     

Is the interdecadal variation of the summer rainfall over eastern China associated with SST?

The present study examined the major features of the interdecadal variation of the summer rainfall over eastern China (IVRC) and the possible association with sea surface temperature (SST). We noted that the first leading mode of IVRC (accounting for nearly half of the total variance and with maximum loading for the summer rainfall anomalies over South China) may be not forced by SST. On the other hand, the second and third leading modes [accounting for 17.1 and 13.6 % of the total variance and mainly associated with the summer rainfall anomalies over the Yangtze River valley (YRV) and North China, respectively] in some extent are forced by SST anomalies. These observational results are confirmed by atmospheric general circulation model (AGCM) simulations forced by observed SST. By eliminating the internal dynamical process driven rainfall though ensemble mean, the simulations further suggest an overall enhancement of the intensity of IVRC in the corresponding ensemble mean, especially in the YRV and North China regions, but not in South China. That implies the different role of SST in driving IVRC over different regions.     

CINRAD/SA雷达频综故障检修方法

频综是多普勒全相参天气雷达的核心部件,其组件工艺水平高且价格昂贵,它提供了整个雷达工作所需的基准信号,共有5路输出,它们分别是9.6MHz主时钟信号、COHO信号、RF DRIVE信号、STALO信号、RF TEST SIGNAL信号.由于不同地区雷达发射机工作频率不同,因此频综不能通用,在台站,备份频综组件不太现实.由于厂家没有提供频综图纸,使得故障判别难度加大.因此通过剖析频综内部结构,给出频综的内部原理简图.针对十多个CINRAD/SA雷达频综出现的故障,划分出三种故障类型,并提出具体维修方法,在此基础上,归纳出该型号雷达在使用过程中频综出现故障时,雷达操作、维护人员应掌握的故障排查方法及技巧,以提高台站的保障能力.     

山西高凡银金矿床黄铁矿的微量元素标型特征及其应用

高凡银金矿床黄铁矿的微量元素研究发现富Au、Ag、Pb、Zn、As、Sb,贫Co、Ni、Se,且S/Se较大,S/As和Fe/(Pb+Zn)较小,As/(Co+Ni)、(Pb+Zn)/(Co+Ni)>10。同时高凡矿田中的滩上铜钼矿化点的黄铁矿则显示相反的特征。总结出一套区分两类矿化黄铁矿微量元素的标型特征,对高凡矿田和五台地区各矿化点的判别和评价中显示了一定的适用性,可作为本区寻找同类金银矿床的找矿标型特征。     

煤的变质程度对焦炭结构构造的影响

从宏观和微观两方面对不同变质程度煤所形成焦炭的结构、构造进行了深入研究。从气煤到肥煤阶段（Ｒｏ，ｍ：０．７７％～１．１６％），焦炭气孔壁厚度逐渐增大；进入焦煤阶段（Ｒｏ，ｍ＞１．１６％），焦炭气孔壁厚度降低。气煤、１３焦煤形成的焦炭结构以各向同性体为主，焦煤、肥煤炼出的焦炭以粒状镶嵌结构为主。由气煤和高变质程度的焦煤形成的焦炭，其气孔以微孔和大孔为主，气孔分布标准差Ｄｓ最大；肥煤炼出的焦炭，其气孔分布大小较均一；１３焦煤和低变质程度的焦煤成焦后，气孔分布状况介于上述二者之间     

Spatial and temporal variation of organic carbon in the northern South China Sea revealed by sedimentary records

Three sediment cores were taken from the Pearl River estuary and adjacent northern South China Sea (SCS). These sediment cores span the time interval 1900–2000 AD. The stratigraphy of the concentration, the ratio of total organic carbon (TOC) to total nitrogen (TN) and stable isotope (δ¹³C_org) of organic carbon (OC) from three high-resolution sediment cores were analyzed. The stratigraphic profiles of OC concentration, TOC/TN ratios and δ¹³C_org for the near past 100 yrs indicate that terrestrial organic matter decreases from 68.3% to 27.4% of the TOC in the Pearl River estuary, while Dapeng Bay (offshore east of Hong Kong) apparently had throughout little terrestrial organic matter input. The highest deposited OC occurs at the Humen River mouth and the OC concentrations are higher in the outer estuary than in the inner shelf of the northern SCS. The deposited OC at the River mouth increased with time, which could be caused by the high precipitation of land-derived organic matter and the high input of terrestrial organic matter, which is likely related to the rapid urbanization and industrial development in the Pearl River Delta since the 1970s. The OC concentrations did not exhibit an obvious increase with time in most areas of the Pear River estuary and adjacent inner shelf of the SCS, but the algal-derived OC concentration inferred from the δ¹³C_org values increased with time especially from 1980 to 2000 in the outer Pearl River estuary and Dapeng Bay. This increase is presumably caused by enhanced primary marine productivity supported by higher anthropogenic nutrient inputs.     

Adsorbed silica in stalagmite carbonate and its relationship to past rainfall

Despite considerable work on other trace elements, the incorporation of dissolved silicon from cave waters into speleothems has not been previously investigated. In this study, the controls on dissolved Si in cave waters and on adsorbed Si in resulting speleothems are therefore investigated. Bedrock (dolomite), soil water, dripping water, and cave carbonates were retrieved from Heshang Cave situated in the central Yangtze valley of China and were subjected to analysis of dissolved Si content (plus accompanying Ca and Fe analyses). Soil waters have Si/Ca of 45.5 mmol/mol, compared to only 3.2 mmol/mol in the dolomite bedrock, demonstrating that >80% of the dissolved Si must come from dissolution of silicate minerals in the soil. Drip waters have a dissolved Si concentration of ≈4.2 μg/mL, similar to that in the overlying soil water. Actively growing cave carbonates have a Si/Ca of 0.075 mmol/mol suggesting a partition coefficient for incorporation of dissolved silicon of 0.0014, in good agreement with previous laboratory studies. Extrapolating the results of these laboratory studies to the cave environment suggests that changes in Si/Ca in cave carbonates are likely to be primarily controlled by changes in drip-water Si/Ca. The drip-water Si/Ca will, in turn, be controlled by the rate of wind-blown silicate supply; by soil weathering rates; by rainfall dilution; and by precipitation of calcite. The general expectation is that these effects combine to produce high Si/Ca in speleothems during times of low rainfall. A δ¹⁸O record from a Heshang Cave stalagmite which grew between 20 and 11 thousand years ago allows these controls to be tested. Correlation of high Si/Ca with high δ¹⁸O demonstrates that regional rainfall exerts significant (but not complete) control on speleothem Si/Ca. With further understanding, speleothem Si/Ca may provide a proxy for past rainfall to complement existing proxies such as δ¹⁸O and Mg/Ca.