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11.
选取2017—2018年6—9月辽宁省不同降水性质, 具有2种不同特征的20次天气过程个例, 应用模糊检验邻域法中的分数技巧评分(Fraction Skill Score, FSS), 评估华东模式、华北模式、GRAPES_3km模式和睿图东北模式对辽宁省中小尺度系统的预报能力。结果表明: 区域性降水过程和局地性降水过程雷达回波强度越小, 邻域半径越大, 高分辨率模式预报技巧越高。当雷达回波大于30 dBz时, 各高分辨率模式对局地性降水的雷达回波预报FSS评分均较高。当邻域半径为3 km时, 区域性降水过程中, 华北模式预报技巧在各级别雷达回波预报中均高于其他模式, 最大FSS差值为0.031。局地性降水过程中, 华东模式预报效果较好, 最大FSS评分为0.127, 表明华东模式预报中小尺度对流系统能力更强。局地性降水过程, 睿图东北模式在08—23时预报时次中, “中间”时次的预报效果优于“两头”时次的预报, 两个时次最大FSS差值为0.121。 相似文献
12.
利用兰州区域气象中心暴雨增强数值预业务系统，对应Ｔ６３模式预报产品资料和不用Ｔ６３模式预报产品资料两种方案进行了对比试验，并逐日分析了１９９６年７月、８月西北区的降水及形势预报结果，对其中几次大的降水过程作了重点讨论。 相似文献
13.
V. Zervakis K. Nittis L. Perivoliotis C. Tziavos 《Journal of Atmospheric & Ocean Science》2002,8(2):151-172
Expendable Bathythermograph (XBT) observations collected along a transect across the Eastern Mediterranean are compared with the respective predictions of thermocline structure and variability produced by the POSEIDON system's ocean circulation model. The observations, obtained in the framework of the Mediterranean Forecasting System project, cover a complete annual cycle, at a repetition rate of 1-2 transects per month, thus providing an excellent data set for estimating the model's skill to forecast seasonal variability and mesoscale circulation in the upper 450 m of the ocean. The comparison has revealed that the model adequately predicts the seasonal cycle of the evolution of the thermocline but tends to generate less steep thermoclines than observed. Furthermore, the mesoscale circulation is not accurately predicted. For the latter, data assimilation is considered a necessary step towards the improvement of the system. 相似文献
14.
本文简述了现代信息社会计算机应用的重要性 ,并结合在台网实际工作中计算机应用过程所遇到问题解决的方法 ;以及计算机使用过程中如何更好地发挥自身功能 ,最大限度地为地震数据的产出服务 ,为提高工作效率从中总结了几种平时十分实用的使用技巧与微机维护方法。 相似文献
15.
本文检验了2020年3月至2021年2月ECMWF和GRAPES以及中央台格点产品（以下简称SCMOC）和省台格点产品（以下简称SPCC）4家降水预报产品逐24h未来5天在贵州的预报质量,结论如下：（1）ECMWF和SCMOC与实况的相关系数最高,SCMOC和SPCC预报降水的变化幅度较观测偏大,而GRAPES预报降水的变化幅度较观测则是明显偏小。（2）SCMOC的晴雨准确率最高,除在72h预报时效SPCC的准确率略高于SCMOC外,其余预报时效SPCC准确率均低于SCMOC,表明SPCC的订正能力需要进一步提升。（3）在小雨量级,4种降水预报产品的TS评分相差不大,ECMWF和GRAPES的ETS评分明显低于SCMOC和SPCC,其中GRAPES的TS评分在5个预报时效内均高于ECMWF。在中雨量级,前3个预报时效内ECMWF的TS和ETS评分均高于其他三家,ECMWF在5个预报时效内预报有降水的次数大于实况出现的降水次数,但空报次数并不是最多的,在后2个预报时效内,SCMOC的TS和ETS评分均是最高的,但与其他家相差不大。在大雨量级,24h和96h预报时效ECMWF的TS和ETS评分均是最高的,而在48h、72h、120h预报时效SCMOC的TS和ETS评分是最高的。在暴雨及以上量级,前3个时效内SPCC 的TS和ETS评分均是最高,且48h的TS评分空间分布也是最优的,表明SPCC对暴雨及以上量级在前3个预报时效内订正能力较好。 相似文献
16.
通过布放在台湾海峡5个浮标冬季(2010年12月至2011年2月)的实测数据对MM5风场的预报结果进行了检验.从空间上看,平潭以北预测风速比实测风速偏高,南部则偏低;随着计算时长的增加,MM5模式预报的平均风速有增加的趋势.通过综合评价检验方法,该模式的短期预报较长期预报效果好.将MM5模式的结果用于台湾海峡冬季平均风场的研究,预测风场和实测风场基本吻合,但台湾海峡靠近台湾一侧模式的平均风速比之前的研究偏小.整体上看MM5较好的体现了台湾海峡冬季风场特点,可以为该区的业务化预报提供参考. 相似文献
17.
Transnational companies as a source of skill upgrading: The electronics industry in Ho Chi Minh City 总被引：2，自引：0，他引：2
Employment and training in TNCs constitute a potential route through which FDI-led industrialization can contribute to national and regional development and economic growth. The article explores this link through the case of TNCs in the electronics industry in Ho Chi Minh City, Vietnam. The skill upgrading contribution of TNCs is related to the type of factories located in Vietnam and the role they play in regional production networks using a model combining the reverse product cycle and regional waves of FDI. Most electronics factories in Vietnam are ‘reproduction factories’ with mature technology and a narrow role in basic component manufacturing; it is shown that their contribution to skill upgrading is correspondingly narrow. Training for the majority of employees is very simple, and those who receive additional training do this especially in labour management, not in technical fields. Only a small group of engineers receive advanced technical training, in Vietnam and in the parent company abroad. The best prospects for increased skill upgrading are found in those companies that are more than reproduction factories for assembly; however, such companies are still few. The TNCs also represent a potential contribution to skill upgrading in local firms through supplier linkages and movement of staff, but when they operate in isolation from a local economy with little absorptive capacity, as in this case, this potential is not realized. 相似文献
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利用2005—2015年安徽省内1162个站点观测资料简要分析了短时强降水的时空分布特征,并利用中国气象局CLDAS(CMA Land Data Assimilation System)近实时降水资料检验2012—2015年安徽省WRF(Weather Research and Forecast)模式对短时强降水的预报性能,探讨不同空间插值方法、检验方法对预报效果的影响,以评估模式预报短时强降水的应用价值和使用注意事项。结果表明:短时强降水主要发生在大别山区和皖南山区;一年中发生次数呈单峰分布,集中于6—8月;日变化呈双峰状,强峰为北京时间下午15:00—19:00,弱峰为06:00—09:00,两个低谷分别为01:00、12:00前后。在两分类评分TS(Threat Score)检验中,各个季节评分均十分低,插值方法对TS评分影响不大。邻域法FSS评分(Fractions Skill Score)检验中,春季FSS评分低,最高仅可达15%,空间窗、时间窗、时间超前或滞后变化对FSS评分的影响不如夏季、秋季明显;夏季,不考虑时间窗时,单独的时间超前或滞后不能提高预报准确率;秋季,模式分别滞后1h或滞后2h预报结果优于同期预报,而超前1h或超前2h预报结果低于同期预报,表明秋季WRF模式对短时强降水的预报有一定滞后性。 相似文献
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This paper reports changes in dissolved organic carbon concentration β(DOC) and the relation between UV-active and non-UV-active components determined for Elbe river water and river bank infiltrate in the Torgau river basin between 1992 and 1994. Using an ultrafiltration method, the fractionation of the DOC content was obtained for the fractions > 10 000 g/mol, 1 000…10 000 g/mol, and < 1 000 g/mol. The spectral absorption coefficient at 254 nm a254 of the molecular-weight fractions was also measured. The mean total DOC concentration of Elbe river water decreased from 6.0 mg/L to below 3.9 mg/L along two investigated flowpaths. Two thirds of the decrease occurred within the first few metres of the river bed and one third along the 350 m length of the groundwater flowpaths. The a254 values showed a significant decrease from 14.8 1/m in Elbe river water to 7.8 1/m in the aquifer. Along a flowpath, the proportion of low-molecular weight fraction of DOC increased, the proportion of high-molecular weight fraction decreased, and the proportion of the 1 000…10 000 g/mol molecular-weight fraction remained relatively stable. The Elbe river water contained the main portion of UV-active compounds in the fraction 1 000…10 000 g/mol, and this was also the case for samples of river infiltrate. For the high-molecular weight fraction, mainly non-UV-active compounds were attenuated in the river bed sediment. 相似文献
20.
尽管确定性预报不是集合预报系统(EPS)的主要目的和应用方向,但其每一个成员的预报表现决定了集合预报系统的预报性能,集合平均也是实际预报业务的一个重要参考指标。为此,利用2013~2015年5~10月的欧洲中期天气预报中心(ECMWF)集合预报系统的降水预报资料,CMORPH(NOAA Climate Prediction Center Morphing Method)卫星与全国3×10~4余个自动气象观测站的逐小时降水量融合资料,研究ECMWF集合预报系统对秦岭周边地区逐日降水的控制预报、成员预报、集合平均的预报能力,并探索提高降水集合平均预报性能的有效方法。主要结论如下:(1)无论是集合平均还是控制预报,整体上都较好的刻画了秦岭周边地区降水的空间形态,比较而言,控制预报能够更好的表现了降水的方差变化。(2)泰勒分析表明,集合平均的降水方差随预报时效增加单调减小,控制预报的方差变化随预报时效的增长振荡较小,其相关系数略优于集合平均。(3)技巧评分表明,集合平均使小雨(降水发生频次)的预报偏差显著增加,增大了空报率;使大雨以上的降水预报偏差减小,增大了漏报率,从而使得大多数情况下,集合平均TS(Threat Score)、ETS(Equitable Threat Score)评分低于控制及扰动成员预报。分析认为这主要是由于降水这一要素的偏态分布特性引起的。(4)集合平均的显著贡献在于能够较好的指示可能发生降水的空间位置。通过阈值限定,调整预报偏差,减少(增大)其对小雨(暴雨)的预报频率,能够使集合平均的TS、ETS评分大幅度提升,预报技巧显著优于成员预报和控制预报。目前,预报偏差Bias订正方法已成功应用于陕西省精细化格点预报系统中。 相似文献