Evaluation of multiple regional climate models for summer climate extremes over East Asia     

Changyong Park  Seung-Ki Min  Donghyun Lee  Dong-Hyun Cha  Myoung-Seok Suh  Hyun-Suk Kang  Song-You Hong  Dong-Kyou Lee  Hee-Jeong Baek  Kyung-On Boo  Won-Tae Kwon 《Climate Dynamics》2016,46(7-8):2469-2486

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热带印度洋海温海盆一致模的变化规律及其对东亚夏季气候影响的回顾   总被引：6，自引：2，他引：4  

黄刚  胡开明  屈侠  陶炜晨  姚帅磊  赵桂洁  姜文萍 《大气科学》2016,40(1):121-130

近十几年,热带印度洋对全球气候的作用越来越受到关注.本文从热带印度洋气候态特征、海温海盆一致模的变化规律以及对东亚夏季气候的影响方面回顾了这些研究工作,并且对这些研究以及存在的不足做了系统的总结.  相似文献   

Regional climate downscaling over Asia-Pacific region     

Hyun-Suk Kang  Fredolin Tangang  R. Krishnan 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(2):77-77

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Changes of precipitation extremes over South Korea projected by the 5 RCMs under RCP scenarios     

Joong-Bae Ahn  Sera Jo  Myoung-Seok Suh  Dong-Hyun Cha  Dong-Kyou Lee  Song-You Hong  Seung-Ki Min  Seong-Chan Park  Hyun-Suk Kang  Kyo-Moon Shim 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(2):223-236

The change of extreme precipitation is assessed with the HadGEM2-AO - 5 Regional Climate Models (RCMs) chain, which is a national downscaling project undertaken cooperatively by several South Korean institutes aimed at producing regional climate change projection with fine resolution (12.5 km) around the Korean Peninsula. The downscaling domain, resolution and lateral boundary conditions are held the same among the 5 RCMs to minimize the uncertainties from model configuration. Climatological changes reveal a statistically significant increase in the mid-21st century (2046- 2070; Fut1) and the late-21st century (2076-2100; Fut2) precipitation properties related to extreme precipitation, such as precipitation intensity and average of upper 5 percentile daily precipitation, with respect to the reference period (1981-2005). Changes depending on the intensity categories also present a clear trend of decreasing light rain and increasing heavy rain. In accordance with these results, the change of 1-in-50 year maximum precipitation intensity over South Korea is estimated by the GEV method. The result suggests that the 50-year return value (RV50) will change from -32.69% to 72.7% and from -31.6% to 96.32% in Fut1 and from -31.97% to 86.25% and from -19.45% to 134.88% in Fut2 under representative concentration pathway (RCP) 4.5 and 8.5 scenarios, respectively, at the 90% confidence level. This study suggests that multi-RCMs can be used to reduce uncertainties and assess the future change of extreme precipitation more reliably. Moreover, future projection of the regional climate change contains uncertainties evoked from not only driving GCM but also RCM. Therefore, multi-GCM and multi-RCM studies are expected to provide more robust projection.  相似文献   

Projections of high resolution climate changes for South Korea using multiple-regional climate models based on four RCP scenarios. Part 1: surface air temperature     

Myoung-Seok Suh  Seok-Geun Oh  Young-Suk Lee  Joong-Bae Ahn  Dong-Hyun Cha  Dong-Kyou Lee  Song-You Hong  Seung-Ki Min  Seong-Chan Park  Hyun-Suk Kang 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(2):151-169

We projected surface air temperature changes over South Korea during the mid (2026-2050) and late (2076-2100) 21st century against the current climate (1981-2005) using the simulation results from five regional climate models (RCMs) driven by Hadley Centre Global Environmental Model, version 2, coupled with the Atmosphere- Ocean (HadGEM2-AO), and two ensemble methods (equal weighted averaging, weighted averaging based on Taylor’s skill score) under four Representative Concentration Pathways (RCP) scenarios. In general, the five RCM ensembles captured the spatial and seasonal variations, and probability distribution of temperature over South Korea reasonably compared to observation. They particularly showed a good performance in simulating annual temperature range compared to HadGEM2-AO. In future simulation, the temperature over South Korea will increase significantly for all scenarios and seasons. Stronger warming trends are projected in the late 21st century than in the mid-21st century, in particular under RCP8.5. The five RCM ensembles projected that temperature changes for the mid/late 21st century relative to the current climate are +1.54°C/+1.92°C for RCP2.6, +1.68°C/+2.91°C for RCP4.5, +1.17°C/+3.11°C for RCP6.0, and +1.75°C/+4.73°C for RCP8.5. Compared to the temperature projection of HadGEM2-AO, the five RCM ensembles projected smaller increases in temperature for all RCP scenarios and seasons. The inter-RCM spread is proportional to the simulation period (i.e., larger in the late-21st than mid-21st century) and significantly greater (about four times) in winter than summer for all RCP scenarios. Therefore, the modeled predictions of temperature increases during the late 21st century, particularly for winter temperatures, should be used with caution.  相似文献   

北斗卫星导航系统双差动力法精密定轨及其精度分析     

刘伟平  郝金明  田英国  于合理  张康 《测绘学报》2016,45(2):131-139

针对GEO卫星切向轨道分量与双差模糊度强相关的问题,对经典双差动力法进行了改进,提出联合使用载波相位和相位平滑伪距实现北斗系统精密定轨,并从理论上分析了以上处理策略的可行性及对模糊度固定的影响,然后结合北斗系统精密定轨特点,推导给出了利用QIF方法实现北斗卫星双差模糊度固定的基本原理,实测数据分析表明:联合载波相位和相位平滑伪距,既可降低相关性,又可兼顾精度,定轨效果优于经典双差动力法;利用QIF方法能够取得一定的模糊度固定效果,但受观测条件限制,北斗卫星双差模糊度固定成功率整体不高,双差模糊度固定之后对轨道的改进作用有限。  相似文献   

利用压密方程计算分析西安市地面沉降特征     

瞿伟  徐超  张勤 《测绘工程》2016,25(2):6-10

利用西安市地下水位监测资料,基于水文地质三维结构模型,在不考虑粘土层滞后压缩变形的理想情况下,采用压密方程计算获得西安市抽取地下水可引起的理论地面沉降量及沉降分布特征,结果表明:计算所得沉降显著区位于西安市西南部的高新区及东南部的曲江新区,沉降量呈由北向南递增的特征,与InSAR监测结果整体趋势具有较好的一致性;地面沉降分布特征受到活动地裂缝影响,沉降曲线呈近NE向偏转展布。研究结果可为沉降灾害预防研究提供宏观的参考信息。  相似文献   

创新型摄影测量教学实验系统的设计     

胡倩伟  刘先林  曲建光  郭增长  刘丹丹  林卉 《测绘科学》2016,41(3):181-184,137

为了在测绘学科教学实践中提高学生的理论水平和分析解决问题的能力,该文以摄影测量的生产流程为主线,研究实现从航空数据获取、像控点测量、空中三角测量、"4D"数据产品生成、三维建模与仿真到GIS属性入库的全过程模拟,旨在解决摄影测量课程教学过程中所面临的抽象、枯燥、高成本、高风险的问题;并以摄影测量实验系统采集的数据为基础,增加了控制测量、GIS入库、三维GIS等实验内容,以期为测绘学科的教学发展以及学生的实践能力提高作出贡献。  相似文献   

Exploring the spatially varying innovation capacity of the US counties in the framework of Griliches’ knowledge production function: a mixed GWR approach   总被引：1，自引：0，他引：1  

Dongwoo Kang  Sandy Dall’erba 《Journal of Geographical Systems》2016,18(2):125-157

Griliches’ knowledge production function has been increasingly adopted at the regional level where location-specific conditions drive the spatial differences in knowledge creation dynamics. However, the large majority of such studies rely on a traditional regression approach that assumes spatially homogenous marginal effects of knowledge input factors. This paper extends the authors’ previous work (Kang and Dall’erba in Int Reg Sci Rev, 2015. doi: 10.1177/0160017615572888) to investigate the spatial heterogeneity in the marginal effects by using nonparametric local modeling approaches such as geographically weighted regression (GWR) and mixed GWR with two distinct samples of the US Metropolitan Statistical Area (MSA) and non-MSA counties. The results indicate a high degree of spatial heterogeneity in the marginal effects of the knowledge input variables, more specifically for the local and distant spillovers of private knowledge measured across MSA counties. On the other hand, local academic knowledge spillovers are found to display spatially homogenous elasticities in both MSA and non-MSA counties. Our results highlight the strengths and weaknesses of each county’s innovation capacity and suggest policy implications for regional innovation strategies.  相似文献   

航空重力仪减振系统振动研究     

屈进红  周锡华  姜作喜  王蓬  高维 《物探与化探》2016,(4):831-837

航空重力减振系统是有效减弱机载环境下高频振动的主要途径,从而提高航空重力的测量精度。因此,设计减振系统的首要问题是设定其合理的刚度、阻尼和质量等重要的特性参数。笔者通过建立航空重力仪两种减振系统类型运动微分方程,经过理论和实例探讨了减振系统模型,旨在深入了解航空重力减振系统的减振规律,为其特性参数设计提供理论依据。  相似文献