Study and Application of Evaluation Method for Weather Impact of Traffic Accident on Zhejiang Freeway

Occurrence degree of the accident on Zhejiang freeway is graded. Evaluation indicator system of weather impact on freeway is established. We use principal component analysis to extract meteorological indicators,and use Logistic regression to establish evaluation model of meteorological indicator,thereby determining evaluation grade of traffic weather impact. Via application test,it is proved that the evaluation on traffic weather condition by the model corresponds with actual situation,which can provide certain decision-making basis for traffic department and the public.

The Impact of Haze Weather on Health: A view to Future

In January 2013, China suffered large-scale haze weather four times, affecting 30 cities in all. The average number of haze weather days in many regions was higher than the same period in every year since 1961. PM2.s, which is defined as fine particulate matter with an aerodynamic diameter of 2.5 micrometers or less, is the main health hazard in the context of haze weather. It can carry large amounts of poisonous and harmful substances, and penetrate deep into the lungs and blood circulation through the respiratory tract, thereby affecting human health.

The alternative of CubeSat-based advanced infrared and microwave sounders for high impact weather forecasting

The advanced infrared(IR) and microwave(MW) sounding systems have been providing atmospheric sounding information critical for nowcasting and improving weather forecasts through data assimilation in numerical weather prediction. In recent years, advanced IR and MW sounder systems are being proposed to be onboard CubeSats that are much more cost efficient than traditional satellite systems. An impact study using a regional Observing System Simulation Experiment on a local severe storm(LSS) was carried out to evaluate the alternative of using advanced MW and IR sounders for high-impact weather forecasting in mitigating the potential data gap of the Advanced Technology Microwave Sounder(ATMS) and the Cross-track Infrared Sounder(CrIS) on the Suomi-NPP(SNPP) or Joint Polar Satellite System(JPSS). It was found that either MicroMAS-2 or the CubeSat Infrared Atmospheric Sounder(CIRAS) on a single CubeSat was able to provide a positive impact on the LSS forecast, and more CubeSats with increased data coverage yielded larger positive impacts.MicroMAS-2 has the potential to mitigate the loss of ATMS, and CIRAS the loss of CrIS, on SNPP or JPSS, especially when multiple CubeSats are launched. There are several approximations and limitations to the present study, but these represent efficiencies appropriate to the principal goal of the study — gauging the relative values of these sensors.

Contributions of Fuqing ZHANG to Predictability,Data Assimilation,and Dynamics of High Impact Weather:A Tribute

This article reviews Fuqing ZHANG’s contributions to mesoscale atmospheric science,from research to mentoring to academic service,over his 20-year career.His fundamental scientific contributions on predictability,data assimilation,and dynamics of high impact weather,especially gravity waves and tropical cyclones,are highlighted.His extremely generous efforts to efficiently transmit to the community new scientific knowledge and ideas through mentoring,interacting,workshop organizing,and reviewing are summarized.Special appreciation is given to his tremendous contributions to the development of mesoscale meteorology in China and the education of Chinese graduate students and young scientists.

Incorporating Stochastic Weather Generators into Studies on Climate Impacts: Methods and Uncertainties

By adopting various stochastic weather generators, different research groups in their recent studies have realized the importance of the effects of climatic variability on crop growth and development. The conventional assessments derived climate change scenarios from General Circulation Models (GCMs) experiments, however, are incapable of helping to understand this importance. The particular interest here is to review the general methodological scheme to incorporate stochastic weather generator into climate impact studies and the specific approaches in our studies, and put forward uncertainties that still exist. A variety of approaches have been taken to develop the parameterization program and stochastic experiment, and adjust the parameters of atypical stochastic weather generator called WGEN. Usually, the changes in monthly means and variances of weather variables between controlled and changed climate are used to perturb the parameters to generate the intended daily climate scenarios. We establish a parameterization program and methods for stochastic experiment of WGEN in the light of outputs of short-term climate prediction models, and evaluate its simulations on both temporal and spatial scales. Also, we manipulated parameters in relation to the changes in precipitation to produce the intended types and qualitative magnitudes of climatic variability. These adjustments yield various changes in climatic variability for sensitivity analyses. The impacts of changes in climatic variability on maize growth, final yield, and agro-climatic resources in Northeast China are assessed and presented as the case studies through the above methods. However, this corporation is still equivocal due to deficiencies of the generator and unsophisticated manipulation of parameters. To detect and simulate the changes in climatic variability is one of the indispensable ways to reduce the uncertainties in this aspect.

台风灾害影响的产业链跨部门传导机制——以台风“天鸽”为例

极端天气事件会通过产业链对经济系统产生级联影响,现有研究聚焦极端天气事件影响评估,但仍未明晰极端天气事件影响在经济系统产业链的跨部门传导机制。该文通过整合自适应区域投入产出模型、结构路径分析和介数中心性分析方法,以台风“天鸽”为例,揭示了台风灾害影响对广东省产业链的跨部门传导机制。研究发现,台风“天鸽”造成广东省经济损失共310亿元,其中间接损失占13%。在台风灾害发生阶段,造成经济损失的关键传导路径与建筑业紧密相关,如非金属矿物制品业→建筑业;关键传输部门包括通信设备、计算机和其他电子设备制造业,金属冶炼和压延加工业等;典型的关键部门间关联包括金属冶炼和压延加工业→建筑业等。在重建阶段,金属矿采选业、金融业、房地产业等部门从重建需求中获得较多经济收益。研究为提高产业链适应能力和灾后资金分配提供决策支持。

海上风电气象服务关键技术及应用分析

[目的]海上风电安全至关重要,气象服务能有效解决影响风电场安全的浪高、风暴潮、强对流以及海雾等预报预警难点问题,保障海上风电项目安全、高效运行。[方法]文章以江苏省海上风电场气象服务为例,通过数据同化技术和最新人工智能方法,结合数值模式,建立海上风电场风-浪-流预报、波浪有效波高和风暴潮智能预报、海上风电场高影响天气监测预报预警等关键技术,最终形成海上风电精细化气象服务与应用,并对气象赋能海上风电产业链和加强不同行业技术融合等提出思考。[结果]结果表明,近海风电场10 m风、100 m风、浪高等要素预报时空分辨率提高至1 h、3 km;有效波高和风暴潮潮位预报时效增至72 h,6 h预报准确率达85%;强对流预警时效提前1 h、海雾预警提前30 min,预报准确率达92%;技术实现了多工作场景的精细化气象服务应用。[结论]研究海上风电气象服务关键技术的应用,能有效提升海上风电安全生产和运维能力,优化海上风电机组发电效率,降低出海作业成本及损耗,保障出海作业安全,减少生命财产损失。此外,随着海上风电的发展,气象服务将不断加强与不同学科的技术融合,赋能海上风电全产业链的发展。

Value-added Impact of Geostationary Hyperspectral Infrared Sounders on Local Severe Storm Forecasts——via a Quick Regional OSSE

Accurate atmospheric temperature and moisture information with high temporal/spatial resolutions are two of the key parameters needed in regional numerical weather prediction(NWP) models to reliably predict high-impact weather events such as local severe storms(LSSs). High spectral resolution or hyperspectral infrared(HIR) sounders from geostationary orbit(GEO) provide an unprecedented source of near time-continuous, three-dimensional information on the dynamic and thermodynamic atmospheric fields—an important benefit for nowcasting and NWP-based forecasting. In order to demonstrate the value of GEO HIR sounder radiances on LSS forecasts, a quick regional OSSE(Observing System Simulation Experiment)framework has been developed, including high-resolution nature run generation, synthetic observation simulation and validation, and impact study on LSS forecasts. Results show that, on top of the existing LEO(low earth orbit) sounders, a GEO HIR sounder may provide value-added impact [a reduction of 3.56% in normalized root-mean-square difference(RMSD)] on LSS forecasts due to large spatial coverage and high temporal resolution, even though the data are assimilated every 6 h with a thinning of 60 km. Additionally, more frequent assimilations and smaller thinning distances allow more observations to be assimilated, and may further increase the positive impact from a GEO HIR sounder. On the other hand, with denser and more frequent observations assimilated, it becomes more difficult to handle the spatial error correlation in observations and gravity waves due to the limitations of current assimilation and forecast systems(such as a static background error covariance). The peak reduction of 4.6% in normalized RMSD is found when observations are assimilated every 3 h with a thinning distance of 30 km.

Surface grain refinement mechanism of SMA490BW steel cross joints by ultrasonic impact treatment

Ultrasonic impact treatment (UIT) is a postweld technique for improving the fatigue strength of welded joints. This technique makes use of ultrasonic vibration to impact and plastically deform a weld toe and can achieve surface grain refinement of the weld toe, which is considered as the main reason for the improvement of fatigue strength. In this paper, the microstructure of the surface of a treated weld toe was observed by metallographic microscopy and transmission electron microscopy (TEM). The results show that UIT could produce severe plastic deformation on the surface layer of the weld toe and the maximum depth of plastic deformation extended to approximately 260 μm beneath the treated surface. Repeated processing could exacerbate the plastic deformation on the surface layer, resulting in finer grains. We can conclude that the surface grain refinement mechanism of SMA490BW welded joints is related to the high density of dislocation tangles and dislocation walls. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.

Space weathering simulation and spectrum decoding

Visible and near-infrared spectra are routinely used to achieve mineral abundances and mineral chemistry of the global surfaces of the Moon and asteroids.However,these spectra can be significantly modified by space weathering,including micrometeorite impacting,solar wind implanting and cosmic ray irradiation.In this paper we report results of laser-bombarding experiments on the Jilin ordinary chondrite,simulating micrometeorite impacting on the surface of asteroids.After laser bombardment,the spectra became significantly redder and moderately darker. With the Modified Gaussian Model(MGM)method,the absorption band positions of olivine can be decoded from the modified spectra,which are correlated with their fayalite contents.In addition,a continuum of the modified spectra can be decoded,and its slope may be used to depict the degree of space weathering.However,relative strengths of the absorption sub-bands of olivine and pyroxenes show significant variant after the bombardment, hence they cannot be used to estimate the relative abundances of high-Ca to low-Ca pyroxenes of the lunar surface and other matured surfaces of asteroids.

考虑极端天气冲击过程的风电机组竞争失效可靠性评估

针对风电机组的运行可靠性易受极端天气影响的问题,提出了一种考虑极端天气冲击过程的风电机组竞争失效可靠性评估方法。同时考虑风电机组自然退化、极端天气冲击导致的瞬时退化以及极端天气持续过程产生的加速退化,构建极端天气下的风电机组综合退化模型;考虑风电机组退化过程对其耐冲击性能的影响,建立风电机组竞争失效可靠度模型以评估风电机组可靠性;基于我国北方某风电场工程数据和极端天气历史数据评估了某2 MW风电机组的可靠性并进行了参数灵敏度分析。结果显示,到第5年时,仅考虑自然退化的方法评估风电机组可靠度为0.84,而考虑极端天气冲击过程的方法评估风电机组可靠度为0.178,后者更加符合工程实际。通过模型参数的灵敏度分析发现,运行时间超过3年后,退化失效开始逐渐影响风电机组的可靠性。

A study on the possible impacts of climate warming on rice production in China

Based on climate change scenarios projected from GCMs (GFDL, UKMO and MPI), this study evaluates possible impacts of climate warming on rice production in China using numerical simulation experiments. A stochastic weather generator is used to make the projected climatic change scenarios suitable to the input of crop model, ORYZA1. The results show that the duration of rice growing season will be lengthened by 6-11 days and the accumulated temperature will increase by 200℃.d-330℃.d when CO2 concentration in the atmosphere doubles. The probability of cool injury in reproductive and grain filling period will decrease while that of heat stress will increase. Rice yield will decrease if cultivars and fanning practices are unchanged. If the dates of rice development stages can be maintained unchanged through cultivar adjustment although rice yield in most parts of the areas will decrease, the decrements will be much less than that when cultivars and farming practices are unchanged.

风电系统高影响天气的时空格局分析

以风电系统为例,基于已有标准和研究,定义和识别了与风速和气温等基本气象要素相关的风电系统高影响天气,并利用近30年气象站观测资料,总结了风电系统高影响天气的时空格局。研究发现,这些高影响天气的区域特征明显:新疆、四川盆地(“三北”、川渝西部和沿海地区)等地多出现影响风电出力的小风天气(大风天气),影响电力设备安全的极大风多出现在我国西部高原山地和东部沿海地区;夏季高温频发(冬季低温频发和电线积冰风险较高)的气象站主要分布在新疆东部、川渝东部、华东中部(东北、蒙西和新疆北部)等地。这些高影响天气的年代际变化也存在差异:我国大部分地区的大风日数和小风日数,以及东北、蒙西和新疆等地的低温日数和电线积冰风险日数在近10年都维持较低水平,这对风电出力和电力系统安全都是有利的;我国大部分区域的极端高温日数近30年来不断增加,这将给我国夏季电力设备的稳定运行和能源保供带来更多风险。

Environmental and Economic Impact of Forest Fires in Puerto Rico 2013-2014

This study presents an analysis of the impact of forest fires in Puerto Rico for the period from 2013-2014. The climatological factors analyzed included precipitation, temperature, relative humidity, and wind. Several factors have combined to the increase of these forest fires, among others, a decrease in precipitation during this period, as well as an increase in the human involvement in these fires from approximately 40% occurs in the night period (5:00 pm to 8:00 am), where the weather conditions do not favor the appearance of these phenomena. An increase in fires of 44% occurred in 2013 compared to 2014, causing an economic loss of $13.8 million. Fire also adversely affected the flora and fauna of the island, but this was not evaluated in this paper.

基于嫦娥五号月壤玻璃揭示月表金属铁的起源研究

月球等无大气天体表面在(微)陨石撞击、太阳风辐照等极端太空环境作用下会发生太空风化,积累产生尺寸从纳米到微米不等的金属铁颗粒。这些金属铁颗粒的存在会显著改变天体表面的光谱特征,这种光谱改造效应会随着金属铁颗粒尺寸的不同而变化,为准确解读天体的遥感数据带来了巨大挑战。尽管经过几十年的研究,不同尺寸的金属铁颗粒形成机制仍未得到明确解答。本文通过对我国嫦娥五号月壤中的玻璃物质进行系统的显微分析,以具有明确撞击成因的旋转形状玻璃珠为切入点,成功区分了在玻璃珠凝固前后分别形成的大、小粒径金属铁颗粒,并证明它们分别源自(微)陨石撞击和太阳风辐照过程,揭示了(微)陨石撞击和太阳风辐照这两种太空环境在太空风化中各自的独特作用,深化了对空间环境与月表物质相互作用机制的理解,并为预测不同太空环境下的风化行为提供了重要的科学依据。

冬季北半球对流层极涡天气型的长期变化特征及其成因

本文首先基于1979~2019年ERA5逐日再分析数据集,采用自组织映射(SOM)神经网络方法对冬季北半球对流层极涡进行客观分型,分析了极涡天气型的时间变化特征,揭示了冬季北半球极涡天气型长期变化的成因。结果表明:(1)根据极涡中心位置,极涡可分为绕极型、偶极型、偏欧亚型和偏北美型,其中绕极型和偶极型为主导环流型。绕极型和偶极型的出现频次分别呈现显著减少和增多的趋势,并具有明显的年际和年代际变化。(2)绕极型的长期减少和偶极型的长期增加主要是由于北极地区快速升温导致北半球中高纬度区域间的经向温度梯度不断减小,大气斜压性减弱,进而引起绕极西风环流减弱,使得北半球极涡的强度减弱,极涡极易分裂。随后基于第六次国际耦合模式比较计划(CMIP6)中一个海气耦合模式(CESM2)的工业革命前参照试验(piControl)和CO_(2)浓度每年增加1%的强迫试验(1pctCO_(2))数据集,采用上述同样的方法进一步探讨了极涡绕极型和偶极型的长期变化与全球增暖的关系,发现无论在piControl还是在1pctCO_(2)试验中绕极型和偶极型极涡仍为主导环流型,但在piControl试验中绕极型和偶极型的出现频次无显著变化趋势,而在1pctCO_(2)试验中绕极型和偶极型则分别表现为显著减少和增多的趋势,进一步验证了观测中这两类极涡天气型的长期变化与全球增暖密切有关。同时本文也使用了CMIP6中其他11种模式做了对比分析,发现结果可靠。

气候变化对园艺作物生产的影响

近年来随着极端天气事件频率和强度的增加,对园艺作物的生长、产量和品质都造成了不同程度的影响。该文通过综述和分析文献资料,基于气候变化中气温升高、降水变化、极端天气事件增加等情况,探讨相关因素对园艺作物的生长发育和产量稳定性的影响,以及气候变化对园艺作物生长环境中土壤水分、温度、光照等因素的变化对不同作物的适应性和产量的影响及当前研究的不足,总结应对气候变化的关键策略并提出未来研究的方向,如优化种植结构、调整栽培措施、采用抗逆性强的品种、改善耕作管理等措施,以提高园艺作物对气候变化的适应能力和生产稳定性,并不断开发更加适应性强的新品种、建立全面有效的气候调控技术体系等,通过综合利用技术手段和管理措施,可以有效减轻极端天气对园艺作物生产的影响,保障农业生产的稳定性和可持续发展。

2022年陇南“4·19”强对流天气成因及其对配电线路故障的影响分析

配电线路长期暴露于自然环境下,易受强对流天气影响而发生故障。2022年4月19日午后,受大风、雷电等高影响天气影响,陇南市13条配电线路先后出现故障。利用陇南市自动气象观测站的极大风速和闪电定位数据以及风云4A(FY-4A)红外云图、探空资料、多普勒天气雷达等资料,对此次强对流天气过程及其对电网影响进行分析。结果表明:(1)此次强对流天气以雷电、雷暴大风天气为主,西和、礼县、武都、康县等县(区)出现大面积用户停电和电力负荷损失等不利影响。(2)强对流发展主要受高原槽和切变线共同影响,在“上冷下暖”的大气层结不稳定条件下,由地面辐合线触发较强的雷暴大风天气;卫星云图和雷达回波也显示对流云团的发生发展与地面雷暴大风相吻合。(3)陇南市配电线路故障范围分布与强对流天气发生时间和过境路径基本一致,利用逐10 min极大风速和闪电定位数据,探讨得出当极大风速值超过15.0 m·s^(-1)、或正地闪电流强度超过43 k A、或负地闪电流强度超过26 k A时,配电线路发生故障的可能性较大。

毫米波云雷达在高影响天气中的预警应用

为提高城市高影响天气的精细化预报预警水平,利用雄安新区2020年1月—2023年12月容城气象站Ka波段毫米波云雷达反射率因子、径向速度等7种产品及地面气象资料和天气学、雷达回波图像形态分析等方法对雄安新区暴雨、大风、雾、霾及沙尘等高影响天气进行分析。结果表明:1)云雷达对含降水的高影响天气云体探测结构清晰、垂直分布特征直观。当春、夏、秋季回波强度≥21 d BZ(冬季≥15 d BZ)、伸展高度≥5 km(冬季≥2 km)的云体出现,且云体最低高度达150 m时,可看作地面降水将出现的特征指标,时间提前量平均达20 min左右,当回波强度减弱、云底高度抬升,降水趋于结束;各级降水中,暴雨的强回波伸展高度、云水含量等最大。2)当回波顶伸展高度达8 km之上而后快速下落至云顶高度≤2 km时,地面易出现8级以上大风,降水伴大风的回波特点为强回波区中形成明显的U或V型缺口,缺口区最大径向速度达12.5 m·s^(-1)左右。3)云雷达反演滴谱数据产品可较好反映各级降水的粒子分布特征;垂直积分液态水含量(Vertically Integrated Liquid Water,VIL)对降水伴大风有预警指示意义,提前量0~30 min或以上。4)非含降水的高影响天气(雾、霾、沙尘等),云雷达回波强度等整体偏弱,各天气现象之间界限不清晰,但与降水天气发生转换时云雷达能快速、清晰地探测出降水云体,有利于提升降水的精细预报预警能力。

老化试验中塑料缺口冲击试样的安装对试验结果的影响

悬臂梁缺口冲击强度是考察塑料耐候性的主要指标之一,本文通过对3种塑料经过氙灯暴露、荧光紫外灯暴露后的悬臂梁缺口冲击强度值的对比分析,清晰表明了在塑料缺口冲击强度试样的耐候性试验中,其暴露方向和安装方式直接影响试验后的缺口冲击强度值,因此,对于塑料光源暴露试验后的缺口冲击强度,无论在设计光源暴露试验方案还是在应用测试结果时,都宜指明试样的暴露方向和安装方式。