大厂锡多金属矿床热液喷气沉积的证据——含矿建造及热液沉积岩

通过对大厂锡多金属矿床含矿建造特征及容矿岩石的岩石学、地球化学研究,探讨了矿床形成的地质环境,证明了主要容矿岩石是从海底热卤水系统中以化学沉淀方式形成的热液沉积岩。     

中国稻田甲烷产生和排放研究Ⅱ.模式研究和减排措施

主要介绍了近 2 0年来稻田甲烷排放的模式研究和排放量的估算以及减少稻田甲烷排放的措施。数值模式是估算稻田甲烷排放量的一条有效途径 ,模式的研究现在正处于发展阶段。介绍了几个主要的模型 ,既有物理过程模型也有经验模型。年排放量的估算范围为 6 79～ 4 1 4Tg ,随着技术的发展和大量实验的进行估算值的精度正得到不断的提高。减排措施是减少稻田甲烷排放的必要手段 ,但是目前的减排技术均处于研究阶段 ,应用还不成熟     

Assimilation of GOES-R Geostationary Lightning Mapper Flash Extent Density Data in GSI 3DVar,EnKF, and Hybrid En3DVar for the Analysis and Short-Term Forecast of a Supercell Storm Case

Capabilities to assimilate Geostationary Operational Environmental Satellite “R-series ”(GOES-R) Geostationary Lightning Mapper(GLM) flash extent density(FED) data within the operational Gridpoint Statistical Interpolation ensemble Kalman filter(GSI-EnKF) framework were previously developed and tested with a mesoscale convective system(MCS) case. In this study, such capabilities are further developed to assimilate GOES GLM FED data within the GSI ensemble-variational(EnVar) hybrid data assimilation(DA) framework. The results of assimilating the GLM FED data using 3DVar, and pure En3DVar(PEn3DVar, using 100% ensemble covariance and no static covariance) are compared with those of EnKF/DfEnKF for a supercell storm case. The focus of this study is to validate the correctness and evaluate the performance of the new implementation rather than comparing the performance of FED DA among different DA schemes. Only the results of 3DVar and pEn3DVar are examined and compared with EnKF/DfEnKF. Assimilation of a single FED observation shows that the magnitude and horizontal extent of the analysis increments from PEn3DVar are generally larger than from EnKF, which is mainly caused by using different localization strategies in EnFK/DfEnKF and PEn3DVar as well as the integration limits of the graupel mass in the observation operator. Overall, the forecast performance of PEn3DVar is comparable to EnKF/DfEnKF, suggesting correct implementation.     

Non-crossing Quantile Regression Neural Network as a Calibration Tool for Ensemble Weather Forecasts

Despite the maturity of ensemble numerical weather prediction(NWP),the resulting forecasts are still,more often than not,under-dispersed.As such,forecast calibration tools have become popular.Among those tools,quantile regression(QR) is highly competitive in terms of both flexibility and predictive performance.Nevertheless,a long-standing problem of QR is quantile crossing,which greatly limits the interpretability of QR-calibrated forecasts.On this point,this study proposes a non-crossing quantile regression neural network(NCQRNN),for calibrating ensemble NWP forecasts into a set of reliable quantile forecasts without crossing.The overarching design principle of NCQRNN is to add on top of the conventional QRNN structure another hidden layer,which imposes a non-decreasing mapping between the combined output from nodes of the last hidden layer to the nodes of the output layer,through a triangular weight matrix with positive entries.The empirical part of the work considers a solar irradiance case study,in which four years of ensemble irradiance forecasts at seven locations,issued by the European Centre for Medium-Range Weather Forecasts,are calibrated via NCQRNN,as well as via an eclectic mix of benchmarking models,ranging from the naive climatology to the state-of-theart deep-learning and other non-crossing models.Formal and stringent forecast verification suggests that the forecasts postprocessed via NCQRNN attain the maximum sharpness subject to calibration,amongst all competitors.Furthermore,the proposed conception to resolve quantile crossing is remarkably simple yet general,and thus has broad applicability as it can be integrated with many shallow-and deep-learning-based neural networks.     

塞浦路斯特罗多斯型洋壳最上部500米剖面(CY—1钻孔)中的不透明矿物、磁性及其蚀变作用的研究

引言近十年来为了鉴别大洋盆地中线性磁异常模式的起源,对洋壳磁化强度的研究显示了极大的兴趣。目前了解洋壳(尤其在深部)可以通过几种方法,如在推测为构造断崖的附近进行海底拖曳打捞、通过大洋基底钻探     

人仍然是最重要的……,但有多久?

很多年轻的天气预报员没有接受或很少接受严格的分析概念方面的训练,同时有经验的预报员由于不经常使用已有的经验而逐渐丢失已有的知识。近十年来逐渐强调使用国家气象中心(NMC)的指导和业务天气预报中的统计方法,不幸的是,与此同时忽视了新预报员(助理预报员)在解决气象学问题(每天天气预报)中对资料的综合和解释方面的训练。这种情况,照我看,将不可避免地使“业务气象学家”(theoperational meteorologist)在本世纪末变成“天气技术员”(the weather technician)。他们将不要再作气象诊断和预报,而仅仅是专门搞解释和把数字转变成文字。这种情况,类似于一个人从来也不锻炼胳膊却希望在棒球比赛中做投手,结果最可能是以伤臂和失败而结束。由于愈强调和依赖数值指导,今天     

日本气象业务计算机系统

一、引言日本气象业务计算机系统(COSME/S)已于1988年2月在日本气象厅总部投入业务,它是一个收集、分析气象资料,制作各种预报,发送各种输出产品的完整的计算机系统。共包括两个主要的子系统:用于气象通信的     

华北强震断层面解和震源深度特征

本文利用远震P波及SH波和区域地震P_(nl)波波形反演方法,测定了华北9次强震的断层面解、震源深度及地震矩.结合其他作者测定的7次地震的结果,分析了华北16次强震断层面解及华北地震震源深度特征.结果表明,华北多数强震为走滑型地震,也有个别正断层型及逆断层型地震;16次地震多数发生在地壳中部10-25km深度范围内.     

一种在天气图上估计Q矢量的简易方法

本文论述了如何从有等压线和等温线的图上来估计 Q 矢量的方向和相对数值。这种矢量场的辐散代表了准地转ω方程中的强迫函数。某一点的 Q 矢量方向是由沿着等温线(在北半球较冷的空气在共左侧)所取的地转风矢量的变率所确定的。Q 矢量方向指向风矢量变率的右侧90°。它的强度正比于矢量风变率的数值和温度梯度的数值。文中论述了一个实际形势中的应用,并把本方法得到的结果与用温度和涡度平流的传统推断方法的结果作了比较,发现两者有普遍的一致性。文中概略绘出了地面高低压理想形势场及高空为槽脊形势下的 Q 矢量和相应垂直运动的分布,给出了对流层低层鞍形气压场和高空急流入口区的汇合锋生的例子,还提到了在锋生和锋消形势下 Q 矢量和垂直环流的型式。     

英国气象局长期天气预报业务的技术方法和商业价值

英国气象局的长期天气预报,是每月第二周的星期一发布。预报时段为1—5天,6—15天和16—30天。预报区有10个,预报要素是平均气温和降水。制作这些预报,首先是报出这三个预报时段的平均地面气压(1—5天的预报只报1000—500hPa 的厚度场)。所使用的预报方法如表1: