面向业务应用的上海地区毫米波云雷达观测质量评估

基于宝山国家基本气象站部署的毫米波云雷达2019年的观测数据,辅以激光雨滴谱、微雨雷达、探空资料、风云四号卫星产品、地面雨量计等多元观测数据,从探测稳定性、探测能力、基数据和产品数据探测合理性等方面开展了毫米波云雷达观测质量评估。结果表明:毫米波云雷达在试验期间仅出现单次软件故障,且基数据全年获取率高于95％,探测稳定性较好;毫米波云雷达各高度最小可测回波强度位于-40～-20 dBZ,并随高度呈现出与理论相符的指数递减;9 km高度以下最小回波强度变化小于2 dB,最小回波探测能力稳定性较高,在降水率达到4～5 mm/h时,毫米波云雷达会出现强衰减导致的虚假晴空区。虽然多部毫米波云雷达的基数据存在差异,但与地面雨滴谱计算回波强度和微型雨雷达观测回波强度具有一致的垂直分布及时间演变特征。毫米波云雷达探测云顶云底高度与探空资料估算云顶云底高度、风云四号卫星反演云顶高度具有一定的一致性。拼接缝和距离旁瓣虚假回波是较为直观且能够对业务化应用产生直接影响的问题。     

S-wave velocity structures of sediments estimated from array microtremor records and site responses in the near-fault region of the 1999 Chi-Chi,Taiwan earthquake

The 1999 Chi-Chi, Taiwan earthquake, M_W = 7.6, caused severe damage in the near-fault region of the earthquake. In order to evaluate site effects in the near-field strong motions we estimate S-wave velocity structures of sediments at four sites using array records of microtremors. We also recalculated S-wave velocity structures at other four sites previously reported. To show the validity of the estimated S-wave velocity structures we separate empirical site responses from aftershock records using the generalized inversion method and show the agreement between empirical and theoretical site responses. We also show an observed fact that suggests soil nonlinearity during the Chi-Chi earthquake by comparing horizontal-to-vertical spectral ratios (HVRs) for main shock records with HVRs for aftershock records. Then we calculate one-dimensional equivalent-linear site responses using the estimated S-wave velocity structures and the main shock records observed on the surface. It is found that site amplification due to thick (about 6 km) sediments is one of the important factors for explaining the long-period velocity pulses of about 5 to 10 sec observed at sites in the footwall during the Chi-Chi earthquake. It is also found that the theoretical site responses of shallow soft sediments at sites that sustained severe damage in the hanging wall shows significant amplification around 1 sec. As the amplitude of velocity pulses with period around 1 sec is most critical in causing damage to ordinary buildings of moderate heights, our results suggest that the 1-sec period velocity pulses, amplified by the site response of shallow sediments should contribute to the severe damage during the Chi-Chi earthquake.     

基于ZigBee协议地面气象观测原型站无线传输系统设计

为满足地面气象自动化实时监测需求,适应气象观测向集约化、标准化和智能化的方向发展,中国气象局气象探测中心在北京观象台建设了代表未来地面气象观测自动化发展的业务原型站,设计了基于ZigBee无线传输系统.该系统采用当今成熟稳定的电子测量、数据传输和控制技术,具有高可靠性、高准确性、易维护、易扩展等特点,支持地面气象数据对...     

基于移动终端的12322地震灾情上报处理系统设计与实现

本文建立了面向公众及应急工作者的移动终端系统,通过约定灾情编码格式,制定解析规则,基于百度地图获取带有地理位置信息的灾情,最终生成了"12322"灾情上报短信及灾情反馈微博。系统分别以Android App和网页两种方式实现,满足了Android系统用户和非Android系统用户的应用需求。系统实现了地震灾情的上报、分析、处理及展示功能,可为地震应急指挥决策提供有力的技术保障,提高应急救援工作的社会参与度和为公众服务的能力。     

山东数字化钻孔体应变观测的干扰异常分析

在系统分析山东钻孔体应变与辅助观测资料的基础上,结合台站工作日志对引起钻孔体应变观测曲线出现波动性短时异常变化的干扰因素进行了分析讨论,结果表明:钻孔体应变的短时波动性变化主要为气压、降雨、地下水位、施工和电源等的干扰影响;这些干扰影响不能通过相关分析完全剔除,需定量与具体情况定性相结合分析;气压、降雨和地下水位的影响程度与钻孔地质条件密切相关,有破碎带的钻孔受干扰影响相对较大。     

未来气候情景下中国东部极端降水和气温的危险性特征

基于BCC-CSM11模式降尺度预估结果,通过构建极端天气气候事件的危险性指数,考察和分析了中国东部极端降水和气温未来气候情景下可能的变化趋势和危险性分布格局。结果表明: 1）在中等排放情景（RCP4.5）下,近期（2021—2050年）极端降水和极端高温危险性呈现增强趋势,危险性指数增幅分别约为2%和10%,而极端低温危险性则呈减弱趋势,危险性指数降幅约为4%。21世纪末期（2070—2099年）,极端降水和气温危险性均基本保持现有水平,未有明显趋势。在高等排放情景（RCP8.5）下,极端降水和极端高温危险性将持续增强,至21世纪末危险性指数增幅分别约为5%和60%;极端低温危险性持续减弱,危险性指数降幅约为5%。2）在未来气候情景下,中国东部极端高温的危险性以全域持续增强为主要特征,特别是西南地区、长江以南地区和东南沿海危险性增强最为显著。至21世纪末,在高排放情景下的危险性指数增幅为30%—60%。极端降水危险性在黄河上游、长江上游和下游以及东北地区中南部等地区呈增强趋势,危险性指数增幅为3%—5%。极端低温危险性全域呈减弱趋势,至21世纪末期高等排放情景下的危险性指数最高降幅为7%—9%。     

Photometry and the determination of oscillation modes for high amplitude Delta Scuti (HADS) variable GSC 1566-2802

CCD photometry observation of a newly discovered, high amplitude Delta Scuti star GSC 1566-2802, with a visible filter, is presented. The observations were carried out at Alborz Observatory located in Mahdasht, Karaj, Iran.The main goal of this project was to update our knowledge of the periodic variations of the target star. This paper covers three analyses, first calculating a new ephemeris and plotting a new light curve based on 19 times of maxima; then a Fourier analysis of the observed data points which results in determining probable oscillation modes, as well as computing its physical parameters which guide us to its harmonics and pulsation modes.     

山西台网地震速报软件定位结果偏差分析

选取2009-2011年山西地震台网的地震事件,运用速报软件进行全自动处理,并进行快速人工修正,与编目结果或中国地震局的正式速报结果进行对比分析,得出速报软件修正后的自动定位结果是可信的,可满足现阶段区域地震台网正式速报参考信息的要求。     

2015年9月16日智利Mw 8.3级地震:海啸波从近场到远场的特征分析

On September 16, 2015, an earthquake with magnitude of M_w 8.3 occurred 46 km offshore from Illapel, Chile,generating a 4.4-m local tsunami measured at Coquimbo. In this study, the characteristics of tsunami are presented by a combination of analysis of observations and numerical simulation based on sources of USGS and NOAA. The records of 16 DART buoys in deep water, ten tidal gauges along coasts of near-field, and ten coastal gauges in the far-field are studied by applying Fourier analyses. The numerical simulation based on nonlinear shallow water equations and nested grids is carried out to provide overall tsunami propagation scenarios, and the results match well with the observations in deep water and but not well in coasts closed to the epicenter. Due to the short distance to the epicenter and the shelf resonance of southern Peru and Chile, the maximum amplitude ranged from 0.1 m to 2 m, except for Coquimbo. In deep water, the maximum amplitude of buoys decayed from9.8 cm to 0.8 cm, suggesting a centimeter-scale Pacific-wide tsunami, while the governing period was 13–17 min and 32 min. Whereas in the far-field coastal region, the tsunami wave amplified to be around 0.2 m to 0.8 m,mostly as a result of run-up effect and resonance from coast reflection. Although the tsunami was relatively moderate in deep water, it still produced non-negligible tsunami hazards in local region and the coasts of farfield.     

地面观测资料同化初步研究

通过对比分析当前两种地面观测资料同化方案(Ruggiero方案和郭永润方案),对其优缺点进行初步分析研究。结果表明:两种同化方案同化地面观测资料后都是从模式低层到高层对分析场产生影响,中低层高度影响比较大,高层影响较小,并且对24 h模拟结果产生一定的影响。Ruggiero方案考虑了模式地形与观测站地形高度差异,但资料剔除较多,且模式分辨率越高,资料剔除对分析场的影响越明显。郭永润方案不考虑模式地形与观测站地形高度差异,假定所有地面观测资料位于模式面,因此无论模式分辨率如何,资料都能得到充分利用,但模式地形与实际观测站地形高度差异大小在地面观测资料同化分析中的影响不可忽略,因此郭永润方案有待改进,适当考虑这两种地形高度差异时效果更好。