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1.
利用2006年NCEP FNL再分析资料和气象站点观测资料,评估中国区域近地面风速WRF动力降尺度效果。结果表明:WRF模式显著高估近地面风速,在风速较大(小)的区域,WRF模式低(高)估了近地面风速;春季和冬季WRF模式模拟的近地面风速误差较大,夏季和秋季模拟的风速误差相对较小;西北干旱区、青藏高原和华南地区WRF模式模拟的风速误差较大,其他地区风速误差相对较小;3种边界层参数化方案(YSU、MYJ和ACM2)中ACM2方案模拟的风速偏差最小。  相似文献   

2.
两种模式在风电场风速预测应用中的对比   总被引:1,自引:0,他引:1  
利用2011年12月至2012年11月贺兰山风电场测风塔实测资料和同期WRF、BJ-RUC模式预测结果,对2种模式在风速预测中的应用进行对比分析。结果发现,月尺度上,2种模式预测的风速月均值普遍较实测值高,且WRF较BJ-RUC更接近实测值;WRF预测的月平均风速标准差普遍较实测低,而BJ-RUC普遍比实测大;春季WRF预测效果整体上较BJ-RUC好,其它季节WRF预测的月平均风速均方根误差较BJ-RUC的小,但与实测风速的相关性较BJ-RUC与实测风速相关性差。日尺度上,凌晨至中午前后和傍晚至前半夜2个时段,2种模式预测风速普遍比实测值大,而中午至傍晚时分正相反,预测值普遍较实测小。2种模式对〉12 m·s^-1风速预测的均方根误差最小,其次是3~12 m·s^-1,〈3 m·s^-1风速预测的均方根误差最大,但BJ-RUC对3~12 m·s^-1范围风速的变化趋势把握能力较好。WRF和BJ-RUC都普遍低估了1~4 m·s^-1风速段的频次,对5~10 m·s^-1范围频次普遍明显高估,对10 m·s^-1以上风速,WRF预测频次较实测低,而BJ-RUC预测频次则较实测高。BJ-RUC对该区风向的预测能力较WRF好。  相似文献   

3.
中尺度气象模式对风场的预报效果与参数化方案的适应性紧密相关.以内蒙古高原丘陵地形、江苏平缓的海陆交界地形2种典型下垫面试验风电场为模拟区域,分别用WRFV3.2 (Weather Research and Forecast Model)模式自带的6种物理过程参数化组合方案预报了2010年1月和7月两个风电场区域的风速和风向,对比分析了参数化组合方案差异对风场预报的影响.结果表明:①内蒙古试验区,边界层MRF方案描述的边界层结构较MYJ方案合理;微物理方案WSM3在夏季的风速预报能力优于WSM6,而冬季相反;复杂地形区域的风场预报需考虑陆面过程参数化方案,尤其是夏季降水发生后,陆面过程对于边界层结构的影响增大,选用Noah优于无陆面过程.②江苏试验区,边界层MRF方案描述的边界层结构较MYJ方案合理;1月陆面过程RUC方案优于陆面热量扩散和Noah;7月陆面热量扩散方案优于RUC和Noah.③风向预报6个方案的预报风向统计与实际记录风向统计有较好的一致性,风向概率分布相似,盛行风向一致且稳定.  相似文献   

4.
藏东南地区是青藏高原山地复杂下垫面的典型代表,其边界层大气过程异常复杂,给数值模拟和预报带来较大困难。大气边界层参数化方案的选取关系到能否正确模拟和预报局地大气过程。本研究采用中尺度模式WRF(Weather Research and Forecasting Model)对藏东南林芝地区对流和稳定边界层大气过程进行模拟,与2013年夏季"藏东南地区复杂下垫面地气交换观测实验"资料对比,研究ACM2,Boulac,M YJ,QNSE和YSU5种边界层参数化方案在青藏高原复杂下垫面的适用性。结果表明:对于水汽混合比垂直结构的模拟,Boulac和MYJ方案分别在模拟对流边界层和稳定边界层时能力最优。ACM 2方案最适宜藏东南复杂下垫面条件下的位温和风速垂直分布的模拟。各边界层参数化方案模拟对流边界层高度均较实际观测偏低,其中,QNSE方案模拟的边界层高度最接近观测。同一种边界层参数化方案对于夜间稳定边界层和正午对流边界层的模拟能力也不相同。该地区边界层风场受地形影响显著,风速较小,模拟的近地层风场较观测偏弱,MYJ和QNSE方案对近地层风场的模拟效果较好。  相似文献   

5.
利用陕西省区域数值模式系统,通过对比WRF中两种大气边界层方案(MJY和YSU),对陕西省2021年7月地面和高空要素预报开展了对比试验。结果表明:地面要素预报上,MYJ方案的24 h累积降水量预报的空报率和漏报率都更低,TS评分更高,预报效果更好,逐小时降水量预报的BIAS评分随预报时效的增加变化更小,空报率、漏报率和TS评分也整体优于YSU方案,表明MYJ方案对降水预报的稳定性更好。两个方案的2 m温度和10 m风场预报存在正偏差,2 m比湿预报存在负偏差,即预报场的温度偏高、风速偏大、湿度偏干,YSU方案在2 m温度和10 m风场预报上效果更好,而MYJ方案在2 m比湿预报上效果更好。高空要素预报上,两个方案在各个高度层上对各个要素的预报各有优劣,其中YSU方案在高空风速预报上较MYJ方案更稳定。  相似文献   

6.
为准确描述我国最大的固定/半固定沙漠-古尔班通古特沙漠区域的大气边界层结构,本文利用该沙漠腹地2017年的梯度铁塔和通量观测数据,基于中尺度气象模式WRF (Weather Research and Forecast v3.7.1),分析了5种边界层参数化方案在古尔班通古特沙漠的适用性。结果表明:1)采用WRF模拟沙漠腹地近地层内的边界层特征时,2m气温的模拟存在冷偏差,5种边界层参数化方案均能较好地模拟出四个季节2m气温的日变化特征,其中非局地方案ACM2(Asymmetric Convective Model version 2)对2m气温效果最好,局地方案BL方案的模拟偏差最大;2)5种边界层参数化方案均能够模拟出10m风速的日变化特征,其中局地方案BL(Bougeault-Lacarrere)对10m风速效果最佳;3)采用WRF模拟沙漠近地层内的地表通量特征时,感热通量存在高估现象,潜热通量存在低估现象,5种边界层参数化方案均能较好地模拟出四个季节模拟时间段内地表净辐射通量的日变化特征,其中局地方案MYJ(Mellor-Yamada-Janjie)的模拟精度最高。  相似文献   

7.
为准确描述我国最大的固定/半固定沙漠—古尔班通古特沙漠区域的大气边界层结构,利用该沙漠腹地2017年的梯度铁塔和通量观测数据,基于中尺度气象模式WRF(Weather Research and Forecast v3.7.1),分析了5种边界层参数化方案在古尔班通古特沙漠的适用性。结果表明:(1)采用WRF模拟沙漠腹地近地层内的边界层特征时,2 m气温的模拟存在冷偏差,5种边界层参数化方案均能较好地模拟出4个季节2 m气温的日变化特征,其中非局地方案ACM2(Asymmetric Convective Model version 2)对2 m气温效果最好,局地方案BL方案的模拟偏差最大。(2)5种边界层参数化方案均能够模拟出10 m风速的日变化特征,其中局地方案BL(Bougeault-Lacarrere)对10 m风速效果最佳。(3)采用WRF模拟沙漠近地层内的地表通量特征时,感热通量存在高估现象,潜热通量存在低估现象,5种边界层参数化方案均能较好地模拟出四个季节模拟时间段内地表净辐射通量的日变化特征,其中局地方案MYJ(Mellor-Yamada-Janjie)的模拟精度最高。  相似文献   

8.
边界层参数化方案对降水预报的影响   总被引:15,自引:1,他引:15       下载免费PDF全文
利用新一代WRF模式模拟了2003年7月8—10日的江淮暴雨,就WRF模式中的MRF和MYJ边界层参数化方案进行了对比试验。发现分辨率为20 km时,WRF模式基本上能够模拟出中尺度降水的范围、位置和强度。采用边界层方案显然比不采用边界层方案的模拟效果好,但是MYJ方案与MRF方案相比并没有明显的优越性。另外发现边界层物理过程对格点尺度降水影响很小,模式主要通过边界层物理过程和积云对流过程之间的耦合,来改善对流性降水的模拟。  相似文献   

9.
许多研究调查了模式预报对边界层方案的敏感性,但是这些研究基本上针对的是热力驱动的混合边界层。对于动力驱动的边界层,不同边界层方案的不同性能以及所带来的不同边界层气象要素的预报还不清楚。运用WRF3.4.1中三种边界参数化方案(YSU、MYJ、ACM2)对新疆2.28大风过程进行数值模拟分析,结果显示:三种边界参数化方案基本能模拟出发生大风的区域及大风过程中10m风速、2m温度和比湿的变化趋势;三种方案模拟的边界层内大气的温度、湿度出现差异与它们对边界层顶的夹卷过程、边界层内垂直混合的处理有关;YSU方案的模拟结果使得更多的高空动量下传,同时更多的有效位能转化为动能,MYJ方案模拟的20m/s的风场区域更大,受地形影响更明显,边界层内湍流更强。  相似文献   

10.
使用WRF中尺度数值模式,分别选用两种不同边界层参数化方案(MYJ,YSU),对2006—06—25洛阳地区一次强飑线边界层结构进行模拟,对比分析近地面层风场、温度场以及边界层日变化特征,结果发现:WRF模式基本模拟出了强飑线过程边界层变化特征;在边界层方案中,MYJ方案描述的边界层结构较YSU方案合理。这表明,用WRF模式能较好地模拟预报飑线的边界层气象要素特征。  相似文献   

11.
Over a period of one year, the moss Scleropodium purum was sampled every two weeks in a French rural area to determine the levels of Li, Na, Al, Si, P, Ca, V, Mn, Fe, Zn, Ba, Hg, and Pb. The element distribution in the moss shoot was studied throughout the year. An apical bioconcentration was discovered for Na, P, Ca, Mn, and Zn, whereas higher levels were found in the basal fraction for Li, Al, Si, V, Fe, Ba, Hg, and Pb. A significant variation of element concentrations was observed during the sampling period. In the apical part Li, Al, Si, V, Fe, Ba, and Hg show maximum levels in the summer and minimum in the autumn. The same pattern was found with Ca and Mn in the whole plant, whereas Na showed opposite fluctuations.  相似文献   

12.
Vulnerability of Aboriginal health systems in Canada to climate change   总被引:1,自引:0,他引:1  
Climate change has been identified as potentially the biggest health threat of the 21st century. Canada in general has a well developed public health system and low burden of health which will moderate vulnerability. However, there is significant heterogeneity in health outcomes, and health inequality is particularly pronounced among Aboriginal Canadians. Intervention is needed to prevent, prepare for, and manage climate change effects on Aboriginal health but is constrained by a limited understanding of vulnerability and its determinants. Despite limited research on climate change and Aboriginal health, however, there is a well established literature on Aboriginal health outcomes, determinants, and trends in Canada; characteristics that will determine vulnerability to climate change. In this paper we systematically review this literature, using a vulnerability framework to identify the broad level factors constraining adaptive capacity and increasing sensitivity to climate change. Determinants identified include: poverty, technological capacity constraints, socio-political values and inequality, institutional capacity challenges, and information deficit. The magnitude and nature of these determinants will be distributed unevenly within and between Aboriginal populations necessitating place-based and regional level studies to examine how these broad factors will affect vulnerability at lower levels. The study also supports the need for collaboration across all sectors and levels of government, open and meaningful dialogue between policy makers, scientists, health professionals, and Aboriginal communities, and capacity building at a local level, to plan for climate change. Ultimately, however, efforts to reduce the vulnerability of Aboriginal Canadians to climate change and intervene to prevent, reduce, and manage climate-sensitive health outcomes, will fail unless the broader determinants of socio-economic and health inequality are addressed.  相似文献   

13.
The global trade of agricultural commodities has profound social-ecological impacts, from potentially increasing food availability and agricultural efficiency, to displacing local communities, and to incentivizing environmental destruction. Supply chain stickiness, understood as the stability in trading relationships between supply chain actors, moderates the impacts of agricultural commodity production and the possibilities for supply-chain interventions. However, what factors determine stickiness, that is, how and why farmers, traders, food processors, and consumer countries, develop and maintain trading relationships with specific producing regions, remains unclear. Here, we use data on the Brazilian soy supply chain, a mixed methods approach based on extensive actor-based fieldwork, and an explanatory regression model, to identify and explore the factors that influence stickiness between places of production and supply chain actors. We find four groups of factors to be important: economic incentives, institutional enablers and constraints, social and power dimensions, and biophysical and technological conditions. Among the factors we explore, surplus capacity in soy processing infrastructure, (i.e., crushing and storage facilities) is important in increasing stickiness, as is export-oriented production. Conversely, volatility in market demand expressed by farm-gate soy prices and lower land-tenure security are key factors reducing stickiness. Importantly, we uncover heterogeneity and context-specificity in the factors determining stickiness, suggesting tailored supply-chain interventions are beneficial. Understanding supply chain stickiness does not, in itself, provide silver-bullet solutions to stopping deforestation, but it is a crucial prerequisite to understanding the relationships between supply chain actors and producing regions, identifying entry points for supply chain sustainability interventions, assessing the effectiveness of such interventions, forecasting the restructuring of trade flows, and considering sourcing patterns of supply chain actors in territorial planning.  相似文献   

14.
This report is a summary of China's climate, as well as major weather and climate events, during 2021. In 2021, the mean temperature in China was 10.5°C, which was 1.0°C above normal (1981–2010 average) and broke the highest record since 1951. The annual rainfall in China was 672.1 mm, which was 6.7% above normal. Also, the annual rainfall in northern China was 40.2% above normal, which ranked second highest since 1961. The rainstorm intensity in the rainy season was strong and featured significant extremes, and disasters caused by rainstorms and flooding were more serious than the average in the past decade. In particular, the extremely strong rainstorm in Henan during July and autumn caused flooding in the middle and lower reaches of the Yellow River with severe consequences. Heatwaves occurred more frequently than normal, and their durations in southern China were longer than normal in summer and autumn. Phased drought was obvious, and caused serious impacts in South China. The number of generated and landfalling typhoons was lower than normal; however, Typhoon In-fa broke the record for the longest overland duration, held since 1949, and affected a wide area. Severe convective weather and extreme windy weather occurred frequently, causing serious impacts. The number of cold waves was more than normal, which caused wide-ranging extremely low temperatures in many places. Sandstorms appeared earlier than normal in 2021, and the number of strong dust storm processes was more than normal.摘要2021年, 中国气候暖湿特征明显, 全国平均气温10.5℃, 较常年偏高1.0℃, 创下了1951年以来最高纪录; 全国平均降水量672.1毫米, 比常年偏多6.7%, 其中北方地区平均降水量较常年偏多40.2%, 为1961年以来第二多. 汛期暴雨过程强度大, 极端性显著, 河南特大暴雨灾害影响重, 黄河中下游流域秋汛明显; 高温过程多, 夏秋南方高温持续时间长; 区域性, 阶段性气象干旱明显, 华南干旱影响较重; 台风生成和登陆均偏少, “烟花”陆地滞留时间长, 影响范围广; 强对流天气强发, 极端大风频发, 局地致灾重; 寒潮过程多, 强度大, 极端低温频现; 沙尘天气出现早, 强沙尘暴过程多.  相似文献   

15.
High-resolution numerical simulation data of a rainstorm triggering debris flow in Sichuan Province of China simulated by the Weather Research and Forecasting (WRF) Model were used to study the dominant cloud microphysical processes of the torrential rainfall. The results showed that: (1) In the strong precipitation period, particle sizes of all hydrometeors increased, and mean-mass diameters of graupel increased the most significantly, as compared with those in the weak precipitation period; (2) The terminal velocity of raindrops was the strongest among all hydrometeors, followed by graupel’s, which was much smaller than that of raindrops. Differences between various hydrometeors’ terminal velocities in the strong precipitation period were larger than those in the weak precipitation period, which favored relative motion, collection interaction and transformation between the particles. Absolute terminal velocity values of raindrops and graupel were significantly greater than those of air upward velocity, and the stronger the precipitation was, the greater the differences between them were; (3) The orders of magnitudes of the various hydrometeors’ sources and sinks in the strong precipitation period were larger than those in the weak precipitation period, causing a difference in the intensity of precipitation. Water vapor, cloud water, raindrops, graupel and their exchange processes played a major role in the production of the torrential rainfall, and there were two main processes via which raindrops were generated: abundant water vapor condensed into cloud water and, on the one hand, accretion of cloud water by rain water formed rain water, while on the other hand, accretion of cloud water by graupel formed graupel, and then the melting of graupel formed rain water.  相似文献   

16.
The results of an investigation about the vertical distribution patterns of selected trace elements in an urban environment, as reflected by their accumulation in lichen transplants, are reported. Thalli of the lichen Pseudevernia furfuracea were transplanted in 2 sites in the urban area of Thessaloniki (N Greece), subjected to very different traffic loads: 1) Tsimiski, downtown of Thessaloniki, at one of the busiest streets of the city, a street canyon 2) Toumba, far from the city centre, at the edge of the city, at an open street. In each site, thalli were suspended along a vertical transect at 3, 6, 9 and 12 m, and retrieved after one year. The results showed that while at Toumba the elemental composition of lichen samples was essentially influenced by natural occurrence, mainly airborne soil dust, at Tsimiski also anthropogenic input of pollutants determined by vehicle traffic was involved for some elements such as Cd, Cu, Ni, Pb and Zn. The vertical distribution patterns of heavy metals accumulated in lichens showed that in general elevation has no statistically significant influence on the concentration of most metals, but this was not true for Pb, whose concentrations increased with increasing elevation from ground. Residents may thus be more exposed to high concentrations of Pb than pedestrians.  相似文献   

17.
An increasing number of publications focus on social vulnerability, resilience, and adaptation (SVRA) towards natural hazards and climate change. Despite this proliferation of research, a systematic understanding of how these studies are theoretically grounded is lacking. Here, we systematically reviewed 4432 articles that address SVRA in various disciplinary fields (e.g. psychology, sociology, geography, mathematics) for various hazards, including floods, droughts, landslides, storm surges, wildfires, tsunamis, earthquakes, and volcano eruptions. We focus on the extent to which these studies explicate the frameworks, theoretical constructs or theories they rely on. Surprisingly, we found that about 90% of the reviewed studies do not explicitly refer to a theoretical underpinning. Overall, theories focusing on individuals’ SVRA were more frequently used than those focusing on systems, society, groups, and networks. Moreover, the uptake of theories varied according to the hazard investigated and field of knowledge, being more frequent in wildfire and flood studies and articles published in social science journals. Based on our analysis, we propose a reflexive handling of theories to foster more transparent, comparable, and robust empirical research on SVRA.  相似文献   

18.
The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.  相似文献   

19.
基于Android的移动气象信息服务系统设计与实现   总被引:2,自引:0,他引:2  
钱峥  赵科科  许皓皓 《气象科技》2014,42(1):99-103
为了丰富移动气象信息服务手段提升服务能力,使用Java,C#,VB,Delphi编程,开发了基于智能终端的移动气象信息服务系统。系统以用户体验为切入点结合智能终端特有的设备特性和移动应用软件特性提供创新型移动气象产品。该系统是一种集气象信息处理、发布和接收为一体的服务系统,用户可以通过该系统随时获取气象信息。介绍了系统的架构设计与客户端设计。详细阐述了采用Java技术在Android平台上研发移动客户端软件过程中所涉及问题的解决方法,包括手势控制、GIS服务、软件管理、系统稳定性和兼容性等问题的解决。  相似文献   

20.
云台山旅游气候资源分析   总被引:8,自引:1,他引:8  
冯家沛 《气象科学》1996,16(4):396-400
本文分析了在连云港市云台风的气候资源:气温、降水、风雾、降雪和结冰,也分析了由气候资源造就的云台山动物、植物资源及云台山的垂直和水平气候带变化,进而得出云台山适合旅游的气候条件。  相似文献   

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