地面气象资料一体化统计加工系统设计与实现

地面气象资料一体化统计加工系统是基于国省统一的CIMISS数据环境,准实时生成日、候、旬、月、年值等统计产品的业务系统,能够满足用户对准实时质控后地面气象资料统计值的业务需求。本文主要介绍地面气象资料实时历史一体化统计加工系统的开发,从软件的需求分析、统计方法、功能实现、关键技术等方面阐述了如何在技术上实现地面气象资料一体化统计加工系统。通过运行策略配置,实现了系统定时自动运行,进一步丰富了CIMISS系统地面气象资料的产品库。     

IPCC国家温室气体清单指南精细化的主要内容和启示

作为IPCC新一轮气候变化综合评估的组成部分,IPCC国家温室气体清单指南进入了正式的精细化阶段,将在2019年形成最终成果,与现有的《IPCC2006指南》合并使用,为“适用于所有缔约方的”《巴黎协定》的实施奠定基础。精细化工作分为提供新方法、更新已有内容、补充/澄清已有内容等三大类,共有107个“精细化点”,涵盖通用方法论、能源活动、工业过程、农业林业和其他土地利用、废弃物等各个领域和部门。中国共有12名专家参与此次工作。建议中国科研工作者尽快以英文著述的形式发表相关成果,提高中国文献的引用率;鉴于中国已具备根据最新指南要求编制清单的能力,建议未来国家温室气体清单的编制尽可能全面转向《IPCC2006指南》及其增补和精细化内容。     

Predicting the visualization intensity for interactive spatio-temporal visual analytics: a data-driven view-dependent approach

The continually increasing size of geospatial data sets poses a computational challenge when conducting interactive visual analytics using conventional desktop-based visualization tools. In recent decades, improvements in parallel visualization using state-of-the-art computing techniques have significantly enhanced our capacity to analyse massive geospatial data sets. However, only a few strategies have been developed to maximize the utilization of parallel computing resources to support interactive visualization. In particular, an efficient visualization intensity prediction component is lacking from most existing parallel visualization frameworks. In this study, we propose a data-driven view-dependent visualization intensity prediction method, which can dynamically predict the visualization intensity based on the distribution patterns of spatio-temporal data. The predicted results are used to schedule the allocation of visualization tasks. We integrated this strategy with a parallel visualization system deployed in a compute unified device architecture (CUDA)-enabled graphical processing units (GPUs) cloud. To evaluate the flexibility of this strategy, we performed experiments using dust storm data sets produced from a regional climate model. The results of the experiments showed that the proposed method yields stable and accurate prediction results with acceptable computational overheads under different types of interactive visualization operations. The results also showed that our strategy improves the overall visualization efficiency by incorporating intensity-based scheduling.     

Observed particle sizes and fluxes of Aeolian sediment in the near surface layer during sand-dust storms in the Taklamakan Desert

Monitoring, modeling and predicting the formation and movement of dust storms across the global deserts has drawn great attention in recent decades. Nevertheless, the scarcity of real-time observations of the wind-driven emission, transport and deposition of dusts has severely impeded progress in this area. In this study, we report an observational analysis of sand-dust storm samples collected at seven vertical levels from an 80-m-high flux tower located in the hinterland of the great Taklamakan Desert for ten sand-dust storm events that occurred during 2008–2010. We analyzed the vertical distribution of sandstorm particle grain sizes and horizontal sand-dust sediment fluxes from the near surface up to 80 m high in this extremely harsh but highly representative environment. The results showed that the average sandstorm grain size was in the range of 70 to 85 μm. With the natural presence of sand dunes and valleys, the horizontal dust flux appeared to increase with height within the lower surface layer, but was almost invariant above 32 m. The average flux values varied within the range of 8 to 14 kg m^?2 and the vertical distribution was dominated by the wind speed in the boundary layer. The dominant dust particle size was PM₁₀₀ and below, which on average accounted for 60–80 % of the samples collected, with 0.9–2.5 % for PM_0–2.5, 3.5–7.0 % for PM_0–10, 5.0–14.0 % for PM_0–20 and 20.0–40.0 % for PM_0–50. The observations suggested that on average the sand-dust vertical flux potential is about 0.29 kg m^?2 from the top of the 80 m tower to the upper planetary boundary layer and free atmosphere through the transport of particles smaller than PM₂₀. Some of our results differed from previous measurements from other desert surfaces and laboratory wind-dust experiments, and therefore provide valuable observations to support further improvement of modeling of sandstorms across different natural environmental conditions.     

Sensitivity of Potential Evapotranspiration Estimation to the Thornthwaite and Penman–Monteith Methods in the Study of Global Drylands

Drylands are among those regions most sensitive to climate and environmental changes and human-induced perturbations.The most widely accepted definition of the term dryland is a ratio,called the Surface Wetness Index(SWI),of annual precipitation to potential evapotranspiration(PET)being below 0.65.PET is commonly estimated using the Thornthwaite(PET Th)and Penman–Monteith equations(PET PM).The present study compared spatiotemporal characteristics of global drylands based on the SWI with PET Th and PET PM.Results showed vast differences between PET Th and PET PM;however,the SWI derived from the two kinds of PET showed broadly similar characteristics in the interdecadal variability of global and continental drylands,except in North America,with high correlation coefficients ranging from 0.58 to 0.89.It was found that,during 1901–2014,global hyper-arid and semi-arid regions expanded,arid and dry sub-humid regions contracted,and drylands underwent interdecadal fluctuation.This was because precipitation variations made major contributions,whereas PET changes contributed to a much lesser degree.However,distinct differences in the interdecadal variability of semi-arid and dry sub-humid regions were found.This indicated that the influence of PET changes was comparable to that of precipitation variations in the global dry–wet transition zone.Additionally,the contribution of PET changes to the variations in global and continental drylands gradually enhanced with global warming,and the Thornthwaite method was found to be increasingly less applicable under climate change.     

策勒沙漠-绿洲输沙及动力环境特征

利用2012年4月9日—5月9日策勒沙漠和绿洲内部测点的输沙及气象资料,分析了沙漠与绿洲内部沙尘传输的差异性,并从风动力环境上揭示了成因。结果表明:(1)观测期间,通过沙漠测点100 cm(宽)×200 cm(高)断面的沙尘总量为117.5 kg,通过绿洲内部棉田相同断面的沙尘总量为15.1 kg,比沙漠测点减少了87.1%;(2)过渡带和防护林带对风速的消减作用明显,观测期间,沙漠测点起沙风的持续时间为97.4 h,棉田测点仅为18.9 h;(3)观测期间,沙漠测点的总输沙势为114.2 VU,合成输沙势为72.8 VU,合成输沙方向为65.5°;棉田测点的总输沙势为16.1 VU,合成输沙势为15.1 VU,合成输沙方向为104.5°。荒漠过渡带和绿洲防护林通过降低绿洲内部的风速,改变动力环境,削弱沙尘在绿洲区的传输。     

乌鲁木齐市边界层日变化特征

利用乌鲁木齐市晴天CFL-03型风廓线雷达观测资料,分析了边界层日变化特征。得出结论如下:边界层结构季节变化明显。冬、春季300~600m以下风速较小,小于3m/s,且愈近地面风速愈小;以上风速大、风向恒定,基本为东南大风。夏季和秋季风速比冬季和春季小,流场特征较复杂,水平风速和风向变化较活跃,存在明显的风切变。折射率结构常数春、秋和冬季比夏季分别小1个、3个和1~3个量级;夏季最大,集中在10~(-16)~10~(-13) m~(-2/3)之间。春、夏和秋季晴天湍流动能耗散率量级分别在10~(-6)~10~(-2) m~2·s~(-3)、10~(-4)~10~(-3) m~2·s~(-3)、10~(-6)~10~(-3) m~2·s~(-3)之间;白天比夜间约大1个量级。晴天折射率结构常数和湍流动能耗散率日变化特征与风场日变化特征有较好地对应关系,即湍流发展旺盛的区域与风速较大的区域相一致。风廓线雷达资料反演的湍流动能耗散率对春季和夏季边界层结构日变化演变特征的监测较好。夏季夜间稳定边界层约400~500m,残余层可达到约1800m,对流边界层可发展到约2500m,混合层约2200m,夹卷层约300~400m。     

城市地质调查钻探地质编录的实践和体会

钻探是城市地质调查的重要技术手段,钻探编录则是直接获取第一手原始资料的重要环节,城市地质调查钻探编录不同于传统的矿产勘探地质编录,内容更为丰富和复杂。文中通过在编录中的实践,向从事此项工作的同行介绍一些心得体会。     

北京平原第四纪下限问题研究

本文首先回顾了北京平原区第四纪下限的研究历史,指出迄今为止在这一领域存在的问题。根据我国目前的研究进展和北京地区研究现状,按照全国地层委员会的相关标准和要求,确定了划分第四纪下限的5大原则。北京平原区第四系沉积特征复杂,根据多年资料和研究结果,我们提出了划分该界限的方法。广大的北京平原区,不具备完整的第四系剖面露头,生物地层方法划分存在困难;古地麟、热释光及孢粉地质测试为准确定位这一界限提供了可能。对平原区的钻孔而言,笔者发现以古地麟测试结合孢粉分析、岩性特征、地球物理测井以及地球化学测试（碳酸钙分析）等综合手段确定这一界限的证据更有说服力,新5孔应用效果较好。