CMIP6高分辨率模式比较计划（HighResMIP）概况与评述     

王磊  包庆  何编 《气候变化研究进展》2019,15(5):498-502

高分辨率模式比较计划(HighResMIP)是第六次国际耦合模式比较计划(CMIP6)的新增计划,旨在研究水平分辨率提高后对气候模式模拟性能的改进,并借助多模式集合的方法降低模拟的不确定性。中国有5个模式团队在CMIP6 GitHub上注册参加HighResMIP。文中对HighResMIP的科学背景、试验设计和参与模式等方面进行了简要介绍,为需要了解该计划的科研人员提供参考。  相似文献   

三种气温预报产品黑龙江省预报效果检验     

孟莹莹  李树岭  赵玲  白雪梅  闫敏慧 《气象与环境学报》2022,38(2):21-30

利用T639模式预报产品和黑龙江省83个国家气象站气温实况观测资料,采用最优预报因子方法选取预报因子,应用多元回归方法建立逐站日最高气温和日最低气温的MOS预报方程; 对MOS、中央气象台指导预报（SCMOC）和T639三种气温预报产品的日最高气温和日最低气温预报效果进行对比检验分析,并用EOF方法检验预报与实况的时空变化特征一致性。结果表明: 与实况的时空变化一致性方面,MOS和SCMOC较好,T639略差; 预报效果方面,MOS和SCMOC对日最高气温和日最低气温的2 ℃预报准确率普遍高于T639,MOS的预报准确率在日最高气温方面高于SCMOC,在日最低气温方面低于SCMOC; MOS对T639气温预报产品改善效果明显,尤其对冬季日最低气温的预报改善效果十分显著; MOS较T639气温预报改善效果与T639模式预报效果呈负相关关系,主要表现为,MOS预报改善效果在T639预报准确率低的山区明显优于平原,在春、夏季,预报准确率较低的日最高气温明显优于日最低气温,在冬季,预报准确率较低的日最低气温优于日最高气温; MOS气温预报方法的预报性能较理想,SCMOC对黑龙江省预报难度较大的日最低气温预报效果较好。  相似文献   

随机物理过程扰动方案在克拉玛依区域集合预报中的应用研究          下载免费PDF全文

史永强  张涵斌  刘郁珏  张歆然 《大气科学学报》2022,45(6):926-937

克拉玛依气象局研发了区域集合预报系统并已实现业务运行,该系统仅采用了集合变换卡尔曼滤波(ETKF)初值扰动,导致离散度发展受到限制,为改善区域集合预报的离散度,本文尝试在初值扰动基础上引入随机物理过程倾向(SPPT)模式扰动方案。通过开展SPPT方案关键参数的敏感性试验,确定了适用于本系统的参数设置,构建了初值-物理过程扰动方案(ETKF-SPPT),并与仅采用初值扰动的集合方案(ETKF)进行了对比。结果表明:ETKF初值扰动方法能够产生具有动力学结构的初值扰动,但是随着预报时效的延长,集合离散度增长很快达到饱和,并在侧边界约束下逐渐减小;ETKF初值扰动结合SPPT模式扰动可使集合离散度在各个预报时效均保持增长状态;集合预报检验结果表明,仅采用ETKF初值扰动的集合预报概率分布可靠性较低,概率预报准确性也较差;ETKF-SPPT方法可获得更好的概率预报结果,可靠性更好,均方根误差更低。对克拉玛依城区一次大风预报个例表明,ETKF方案对大风起风时间和量级把握较差,而ETKF-SPPT可以增加集合离散度,起风时间和风速预报更准确。综合而言,增加SPPT扰动可以有效改善克拉玛依区域集合预报系统的预报技巧。  相似文献   

Extracting ecological information from oblique angle terrestrial landscape photographs: Performance evaluation of the WSL Monoplotting Tool     

《Applied geography (Sevenoaks, England)》2015

While aerial photography and satellite imagery are the usual data sources used in remote sensing, land based oblique photographs can also be used to measure ecological change. By using such historical photographs, the time frame for change detection can be extended into the late 1800s and early 1900s, predating the era of aerial imagery by decades. Recent advancements in computing power have enabled the development of techniques for georeferencing oblique angle photographs. The WSL Monoplotting Tool is a new piece of software that opens the door to analyzing such photographs by allowing for extraction of spatially referenced vector data from oblique photographs. A very large repeat photography collection based on the world's largest systematic collection of historical mountain topographic survey images, the Mountain Legacy Project, contains >6000 high resolution oblique image pairs showing landscape changes in the Rocky Mountains of Alberta between ca. 1900 – today. We used a subset of photographs from this collection to assess the accuracy and utility of the WSL Monoplotting Tool for georeferencing oblique photographs and measuring landscape change. We determined that the tool georeferenced objects to within less than 15 m of their real world 3D spatial location, and the displacement of the geographic center of over 121 control points was less than 3 m from the real world spatial location. Most of the error in individual object placement was due to the angle of viewing incidence with the ground (i.e., low angle/highly oblique angles resulted in greater horizontal error). Simple rules of control point selection are proposed to reduce georeferencing errors. We further demonstrate a method by which raster data can be rapidly extracted from an image pair to measure changes in vegetation cover over time. This new process permits the rapid evaluation of a large number of images to facilitate landscape scale analysis of oblique imagery.  相似文献   

市县级土地开发整理管理信息系统的研究与实现   总被引：1，自引：0，他引：1  

张书波  侯迪 《国土资源信息化》2009,(3):8-13

本文针对市县级土地开发整理管理的需求,分析了现行市县级土地开发整理项目管理模式的现状,提出了建设土地开发整理管理信息系统,明确了系统的建设目标,研究了系统应具备的主要功能并进行了系统的总体设计与实现。  相似文献   

Organic geochemistry of Deep Sea Drilling Project sediments from the Gulf of Calofornia—hydrothermal effects on unconsolidated diatom ooze     

Bernd R.T. Simoneit  R.P. Philp  P.D. Jenden  E.M. Galimov 《Organic Geochemistry》1984,7(3-4)

The effects of intrusive thermal stress have been studied on a number of Pleistocene sediment samples obtained from Leg 64 of the DSDP-IPOD program in the Gulf of California. Samples were selected from Sites 477, 478 and 481 where the organic matter was subjected to thermal stress from sill intrusions. For comparison purposes, samples from Sites 474 and 479 were selected as representative of unaltered material.The GC and GC-MS data show that lipids of the thermally unaltered samples were derived from microbial and terrestrial higher-plant detritus. Samples from sill proximities were found to contain thermally-derived distillates and those adjacent to sills contained essentially no lipids. Curie point pyrolysis combined with GC and GC-MS was used to show that kerogens from the unaltered samples reflected their predominantly autochthonous microbial origin. Pyrograms of the altered kerogens were much less complex than the unaltered samples, reflecting the thermal effects. The kerogens adjacent to the sills produce little or no pyrolysis products since these intrusions into unconsolidated, wet sediments resulted in in situ pyrolysis of the organic matter.Examination of the kerogens by ESR showed that spin density and line width pass through a maximum during the course of alteration but ESR g-values show no correlation with maturity. Stable carbon isotope (δ¹³C) values of kerogens decrease by 1–1.5‰ near the sills at Sites 477 and 481 and the atomic N/C decreases slightly with proximity to a smaller sill at Site 478. Differences in maturation behavior between Site 477 and 481 and Site 478 are attributed to dissimilarities in thermal stress and to chemical and isotopic heterogeneity of Guaymas Basin protokerogen.  相似文献   

江苏丰县县城规划区深层孔隙水开采动态及水位预测     

赵中省 《江苏地质》1997,21(2):93-97

简要论述丰县县城的水文地质条件；对丰县县城规划区主要供水源深层孔隙水的开采作了动态分析；建立了地下水位灰色预测模型并预测了２０００年的水位及水位变化区间。  相似文献   

STABILITY ANALYSIS OF COFFERDAM SLUMP AND ITS APPLICATION IN THE CLOSURE OPERATION OF THREE GORGES PROJECT   总被引：1，自引：0，他引：1  

WANG Guangqian Professor  Dept. of Hydraulic Engineering  Tsinghua University  Beijing  China ZHOU Hougui Senior Engineer  Gezhouba Group Corporation  Yichang Hubei  China LIU Lubo Master Student  Dept. of Hydraulic Engineering  Tsinghu 《国际泥沙研究》1997,(3)

I.INTRODUCTIONTheclosureoperationofThreeGorgesprojectisfamousintheworldforitslargedischarge,deepwater,lowvelocityinclosuregaps,largequantitiesandhighintensityforfillingmaterials.Thus,thedikeconstT'Uctionintheclosureoperationprocessisverydifficult.Sothedesign,researchandconstrUctiongroupshavepaidmuchenergyinthedesignprinciplesandoptimalitymeasuresofthegrandriverclosureoperation.FromtheexperimentsofhydraulicsanddikeslumpinthesecondperiodofclosureoperationattheResearchinstitUteofYangtZeR…  相似文献   

香港降水的短期气候预测   总被引：1，自引：0，他引：1  

简裕庚  周文  陈创买  温之平 《热带地理》2001,21(2):125-130

利用正规化周期回归分析方法和门限自回归理论对香港1853-1995年月降水资料进行了建模和拟合，并对1996年进行了预报试验，正规化周期回归拟合效果较好，对香港7个时距的试报准确率为71%，建立了7个时距的10年滑动平均序列的门限自回归模型，模型对序列拟合效果较理想，预报误差较小，试报准确率主国100%。  相似文献   

Reservoir resettlement in China: past experience and the Three Gorges Dam   总被引：2，自引：0，他引：2  

Li Heming  Paul Waley  & Phil Rees 《The Geographical journal》2001,167(3):195-212

This paper reviews involuntary resettlement resulting from dam-building, which has been ignored relative to the dominant focus of migration research in China, rural to urban migration. Reservoir resettlement in China has a long history, often of misery and hardship for those displaced. Relocatees affected by the Three Gorges Project (1994–2009) on the Yangtze River face a similar situation. In China priority has been given to building the dam to provide electricity, flood control and navigation. Less attention has been paid to the problems of the people affected by the reservoir inundation. The rural population forced to relocate and rural-urban migrants in general have been discriminated against by national policies.  相似文献