Analysis of ice water path retrieval errors over tropical ocean

Retrieval of multi-layered cloud properties, especially ice water path (IWP), is one of the most perplexing problems in satellite cloud remote sensing. This paper develops a method for improving the IWP retrievals for ice-over-water overlapped cloud systems using Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Visible and Infrared Scanner (VIRS) data. A combined microwave, visible and infrared algorithm is used to identify overlapped clouds and estimate IWP separately from liquid water path. The retrieval error of IWP is then evaluated by comparing the IWP to that retrieved from single-layer ice clouds surrounding the observed overlapping systems. The major IWP retrieval errors of overlapped clouds are primarily controlled by the errors in estimating the visible optical depth. Optical depths are overestimated by about 10–40% due to the influence of the underlying cloud. For the ice-over-warm-water cloud systems (cloud water temperature Tw > 273 K), the globally averaged IWP retrieval error is about 10%. This cloud type accounts for about 15% of all high-cloud overlapping cases. Ice-over-super-cooled water clouds are the predominant overlapped cloud system, accounting for 55% of the cases. Their global averaged error is 17.2%. The largest IWP retrieval error results when ice clouds occur over extremely super-cooled water clouds (Tw 6 255 K). Overall, roughly 33% of the VIRS IWP retrievals are overestimated due to the effects of the liquid water clouds beneath the cirrus clouds. To improve the accuracy of the IWP retrievals, correction models are developed and applied to all three types of overlapped clouds. The preliminary results indicate that the correction models reduce part of the retrieval error.     

莫桑比克阿尔特里哥纳伟晶岩区概貌

莫桑比克阿尔特里哥纳是世界著名的伟晶岩区之一,蕴藏着丰富的稀有金属、稀土、水晶和宝石等矿产资源。伟晶岩脉及其矿体的分布受北北东—北东向和北西向断裂控制,北北东—北东向分布的伟晶岩矿床以稀有金属矿种为主,北西向分布的伟晶岩矿床以稀土金属矿种为主。伟晶岩体及其矿体呈脉状和透镜状等,规模大,富含钽铁矿、铌铁矿、锂云母、锂辉石、绿柱石、独居石、铌钇矿、烧绿石和泡铋矿等矿物。伟晶岩年龄410M a~560M a,是泛非构造运动的产物。按岩浆凝固浓度等分类,伟晶岩类型为稀有金属伟晶岩,部分为浅成、晶洞状伟晶岩;按化学成分等分类,伟晶岩以钠锂型为主,部分为钾型。伟晶岩体有明显的结构分带。     

长江中下游深部找矿取得突破

江苏省镇江市韦岗铁矿位于长江中下游铁（铜）成矿带宁镇成矿区中段，为一隐伏高硫磁铁矿床，累计查明铁矿石总储量为1710万t。随着开采规模的逐步加大，截至2006年底，矿山保有储量为339万t，仅可维持开采4年。2006年12月，韦岗铁矿被列为全国危机矿山接替资源找矿项目。江苏省地调院承担后，在对以往该区勘查资料进行综合研究的基础上，对该矿区成矿地质条件、物探重磁异常进行分析研究，认为矿区地表以下500m～800m有较大矿体赋存的可能。2008年，项目组先后开展了坑探、磁测、钻探等工作，     

长江中下游成矿带（江苏段）铜矿资源地球化学定量预测

利用江苏省1:20万区域化探资料,结合中大比例尺化探普查成果,运用GIS技术,提取剥蚀程度、相似度和衬值等地球化学信息,结合成矿带不同成因类型铜矿找矿模型,建立长江中下游成矿带(江苏段)铜矿地球化学定量预测模型,并进行铜矿预测区圈定、分级和铜矿资源量估算,为该矿带铜矿勘查工作部署提供了依据。