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911.
该文利用同步物理反演法以6小时数值预报场为背景场对1992年1月份NOAA-12卫星垂直探测(TOVS)资料进行了大气参数反演,并对水汽反演误差进行了检验和分析.以常规观测作为检验的标准,检验结果按3条轨道统计,发现反演的相对湿度平均误差与背景场的误差密切相关,均为负值;在高层和高纬度,误差绝对值随高度的增加而增加,随纬度的升高而增加;误差的日际变化在高层比较稳定,低层振动较大.对反演误差进行订正后的结果表明,在500hPa以上反演均比背景质量要好,尤其轨道A所有层次上订正后的反演比背景场好. 相似文献
912.
为了了解近20 a郑州市大雾的时空变化特征,根据1980-2005年郑州市大雾观测记录,统计分析了这一时期郑州市大雾的变化特点及产生大雾时的气象要素特征;并利用河南省地面和探空观测资料以及NCEP1°×1°再分析资料,从要素场、大气稳定度等方面,对2007年12月25-27日郑州市大雾形成原因进行了分析.结果表明:郑州市年雾日数呈下降趋势,每月都可以出现大雾,但12月最多,6月最少.降水后较大的相对湿度、稳定的大气层结以及近地层较小风速等是大雾形成的必要条件. 相似文献
913.
青藏高原地区云对地面有效辐射的影响:Ⅱ.强迫作用 总被引:2,自引:0,他引:2
本文利用1982年8月-1983年7月青藏高原地面热源观测试验资料,讨论了与云对地面有效辐射强迫作用有关的参数的计算问题,并对这些参数的计算结果进行了分析。结果表明:晴空、全云条件下的地面有效辐射和云对地面有效辐射强迫作用的年平均日变化振幅有明显的地域差异;云对地面有效辐射的强迫作用春夏大,秋冬小,甘孜、拉萨、那曲和改则4站平均的年平均值为-27.2W/m^2。? 相似文献
914.
Qi Zhang Jiquan Zhang Denghua Yan Yongfang Wang 《Theoretical and Applied Climatology》2014,117(1-2):169-174
Extreme weather events include unusual, severe or unseasonal weather, and weather at the extremes of the historical distribution. They have become more frequent and intense under global warming, especially in mid-latitude areas. They bring about great agricultural and economic losses. It is important to define the threshold of extreme weather event because it is the starting point of extreme weather event research, though it has been of seldom concern. Taking extreme precipitation events in Anhui, China as an example, the detrended fluctuation analysis (DFA) method is introduced to define the threshold of extreme weather events. Based on it, the spatial and temporal distributions of extreme precipitation events are analyzed. Compared to the traditional percentile method, DFA is based on the long-term correlation of time series. Thresholds calculated by DFA are much higher than the 99th percentile and the values are higher in the south and lower in the north. This spatial pattern is similar to the annual precipitation spatial pattern. There is an obvious increasing trend in the number of days with extreme precipitation, especially after the 1980s. This observation supports the point that more extreme events happen under global warming. 相似文献
915.
以厦门市旅游业为研究样本,采用系统分析,围绕气候变化对旅游业发展的影响,建立气候变化对旅游业发展影响的评价指标体系,利用层次分析法对各指标因子进行权重测算,再利用模糊综合评价法进行评价,将气候变化对厦门旅游业的影响进行定量分析。结果显示,气候变化对旅游业的影响的隶属度最大值为0.309,是较强的。研究可以明确将旅游业发展过程中受气候变化影响的各个方面,按照受影响程度高低进行划分,从而可以有效指导旅游业相关从业者对风险进行归类,进而协调各方利益,有针对性地发展旅游业,从而实现旅游资源的长期利用和旅游业的可持续发展。 相似文献
916.
Shanghai experienced the longest rainy days in 2018/2019 winter since 1988. The physical cause of such an unusual climate condition was investigated through the diagnosis of observational data. From a seasonal perspective, a long persistent rainy winter was often associated with an El Niño condition in the equatorial Pacific. This abnormal oceanic condition induces a remote teleconnection pattern with pronounced low-level southerly anomalies over East China. The wind anomalies transported moisture from tropical oceans and caused persistent rainfall in East Asia. Meanwhile, the local rainfall time series exhibited a strong quasi-biweekly oscillation (QBWO). Three persistent rainy events were identified in the 2018/2019 winter and they all occurred during the active phase of the QBWO. The first two events were associated with a low pressure anomaly west of Shanghai. Southerly anomalies associated with the low pressure system advected high mean moisture into central eastern China, leading to the persistent rainfall there. The third event was associated with a high pressure anomaly in lower troposphere to the east of Shanghai, which induced anomalous southerlies to its west, favoring the occurrence of rainfall in Shanghai. The result suggests the importance of high-frequency variability in affecting seasonal rainfall anomalies. 相似文献
917.
In this paper, lead-time and spatial dependence in skill for prediction of monthly mean climate variability is analyzed. The analysis is based on a set of extensive hindcasts from the Climate Forecast System at the National Centers for Environmental Prediction. The skill characteristics of initialized predictions is also compared with the AMIP simulations forced with the observed sea surface temperature (SST) to quantify the role of initial versus boundary conditions in the prediction of monthly means. The analysis is for prediction of monthly mean SST, precipitation, and 200-hPa height. The results show a rapid decay in skill with lead time for the atmospheric variables in the extratropical latitudes. Further, after a lead-time of approximately 30?C40?days, the skill of monthly mean prediction is essentially a boundary forced problem, with SST anomalies in the tropical central/eastern Pacific playing a dominant role. Because of the larger contribution from the atmospheric internal variability to monthly time-averages (compared to seasonal averages), skill for monthly mean prediction associated with boundary forcing is also lower. The analysis indicates that the prospects of skillful prediction of monthly means may remain a challenging problem, and may be limited by inherent limits in predictability. 相似文献
918.
919.
利用鲁西南地区雾日与同期、前期全球500hPa高度资料,统计得出欧亚大陆槽脊位置,亚洲南北两支锋区的位置、强度、走向等与鲁西南地区雾日密切相关,并选取优势因子建立鲁西南地区月、旬、候雾日预测方程,试报结果表明,用前期全球500hPa高度资料预测雾日具有一定的效果。 相似文献
920.