Based on the conventional observation data and NCEP/NCAR reanalysis data,the circulation situation,influencing systems and causes of the heavy rain during September 20-21,2010 in Ulanqab City were analyzed from the ev...Based on the conventional observation data and NCEP/NCAR reanalysis data,the circulation situation,influencing systems and causes of the heavy rain during September 20-21,2010 in Ulanqab City were analyzed from the evolution process of weather circulation situation and the changes of various physical quantity fields.The results show that there was an obvious frontal zone between 45-52°N,which brought strong cold air.The transport of warm and humid air outside the subtropical high and typhoon was the main water vapor source of the strong precipitation,and the southwest jet at 700 hPa transported abundant water vapor.There was a broad inverted trough to the south of 45°N,with a central value of 1000.0 hPa.Ulanqab City was on the top of the inverted trough,stable and less moved,which was conducive to the occurrence of systematic heavy precipitation.The rainstorm was a strong precipitation process caused by the intersection of cold air brought by the southward movement of the upper frontal zone and warm and humid air outside the subtropical high.After the precipitation,the invasion of strong cold air brought frost and cold wave weather to Ulanqab City.展开更多
The El Ni?o Southern Oscillation(ENSO) is a natural phenomenon that relates to the fluctuation of temperatures over the Pacific Ocean. The ENSO significantly affects the ocean dynamics including upwelling event and co...The El Ni?o Southern Oscillation(ENSO) is a natural phenomenon that relates to the fluctuation of temperatures over the Pacific Ocean. The ENSO significantly affects the ocean dynamics including upwelling event and coastal front. A recent study discovered the seasonal upwelling in the east coast of Peninsular Malaysia(ECPM), which is significant to the fishery industry in this region. Thus, it is vital to have a better understanding of the influence of ENSO towards the coastal upwelling and thermal front in the ECPM. The sea surface temperature(SST) data achieved from moderate resolution imaging spectroradiometer(MODIS) aboard Aqua satellite are used in this study to observe the SST changes from 2005 to 2015. However, due to cloud cover issue, a reconstruction of data set is applied to MODIS data using the data interpolating empirical orthogonal function(DINEOF) to fill in the missing gap in the dataset based on spatial and temporal available data. Besides, a wavelet transformation analysis is done to determine the temperature fluctuation throughout the time series. The DINEOF results show the coastal upwelling in the ECPM develops in July and reaches its peak in August with a clear cold water patch off the coast. There is also a significant change of SST distribution during the El Ni?o years which weaken the coastal upwelling event along the ECPM. The wavelet transformation analysis shows the highest temperature fluctuation is in 2009–2010 which indicates the strongest El Ni?o throughout the time period. It is suggested that the El Ni?o is favourable for the stratification in water column thus it is weakening the upwelling and thermal frontal zone formation in ECPM waters.展开更多
The map expression of ＂abrupt＂ changes in lateral stratigraphic level of a thrust fault has been traditionally interpreted to be a result of the presence of （1） a lateral （or oblique） thrust-ramp, or （2） a fro...The map expression of ＂abrupt＂ changes in lateral stratigraphic level of a thrust fault has been traditionally interpreted to be a result of the presence of （1） a lateral （or oblique） thrust-ramp, or （2） a frontal ramp with displacement gradient, and/or （3） a combination of these geometries. These geometries have been used to interpret the structures near transverse zones in fold-thrust belts （FTB）. This contribution outlines an alternative explanation that can result in the same map pattern by lateral variations in stratigraphy along the strike of a low angle thrust fault. We describe the natural example of the Leamington transverse zone, which marks the southern margin of the Pennsylvanian-Permian Oquirrh basin with genetically related lateral stratigraphic variations in the North American Sevier FTB. Thus, the observed map pattern at this zone is closely related to lateral stratigraphic variations along the strike of a horizontal fault. Even though the present-day erosional level shows the map pattern that could be interpreted as a lateral ramp, the observed structures along the Leamington zone most likely share the effects of the presence of a lateral （or oblique） ramp, lateral stratigraphic variations along the fault trace, and the displacement gradient.展开更多
2021/2022年冬季,赤道中东太平洋海温偏低,导致贵州省气温偏低、降水偏多,但凝冻日数总体偏少,呈前期偏弱后期偏强的阶段性分布特征。利用贵州省84个国家气象观测站逐日观测资料、NCEP/NCAR(National Centers for Environmental Predict...2021/2022年冬季,赤道中东太平洋海温偏低,导致贵州省气温偏低、降水偏多,但凝冻日数总体偏少,呈前期偏弱后期偏强的阶段性分布特征。利用贵州省84个国家气象观测站逐日观测资料、NCEP/NCAR(National Centers for Environmental Prediction/National Center for Atmospheric Research)再分析资料以及NOAA(National Oceanic and Atmospheric Administration)海温资料等,分别从海温场、高度场、风场、温度场和水汽条件等方面对凝冻阶段性特征成因进行分析。结果表明:高层南支锋区总体呈前期偏弱后期偏强,为贵州省凝冻阶段性特征提供了有利的大尺度环流背景。2022年1月26日之后,对流层低层切变线稳定维持、偏北气流异常强盛使0℃等温线南压明显。同时随着偏南气流持续增强,对流层低层水汽辐合也迅速增强,并维持低层辐合中层辐散的不稳定层结和上升运动,为贵州省凝冻阶段性特征提供了有利的水汽条件。温度场上,前期暖层较为深厚,冷空气势力前期偏弱后期偏强,为贵州省凝冻阶段性特征提供了有利的温度条件。但由于整个冬季无逆温层存在,导致3次区域性凝冻过程强度均偏弱。展开更多
基于NCEP再分析资料、EC资料和常规观测资料,应用天气分析和诊断分析方法,对2016年1月广西的低温雨雪天气进行了分析,结果表明:(1)此次低温雨雪天气与阻塞高压的强而稳定密切相关。冷空气之强盛为历史所罕见,与历史同期相比,地面冷高压...基于NCEP再分析资料、EC资料和常规观测资料,应用天气分析和诊断分析方法,对2016年1月广西的低温雨雪天气进行了分析,结果表明:(1)此次低温雨雪天气与阻塞高压的强而稳定密切相关。冷空气之强盛为历史所罕见,与历史同期相比,地面冷高压显著偏强,850 h Pa的0℃线明显偏南。850 h Pa华南强锋区的长时间维持,是造成此次过程的重要原因之一。(2)雨夹雪与雪的条件相似,主要是温度垂直结构存在差异;而降雪与降雨相比,温度垂直结构、云顶高度、逆温层顶部气温以及暖层的厚度、高度、强度、地面气温均有明显的区别。(3)降水相态由雨转为雪时,广西上空的锋面垂直结构有明显的变化。(4)持续而强盛的水汽输送、湿层深厚有利于阴雨、雪天气的发生及持续。相关分析结论可为广西低温雨雪冰冻预报提供技术参考。展开更多
文摘Based on the conventional observation data and NCEP/NCAR reanalysis data,the circulation situation,influencing systems and causes of the heavy rain during September 20-21,2010 in Ulanqab City were analyzed from the evolution process of weather circulation situation and the changes of various physical quantity fields.The results show that there was an obvious frontal zone between 45-52°N,which brought strong cold air.The transport of warm and humid air outside the subtropical high and typhoon was the main water vapor source of the strong precipitation,and the southwest jet at 700 hPa transported abundant water vapor.There was a broad inverted trough to the south of 45°N,with a central value of 1000.0 hPa.Ulanqab City was on the top of the inverted trough,stable and less moved,which was conducive to the occurrence of systematic heavy precipitation.The rainstorm was a strong precipitation process caused by the intersection of cold air brought by the southward movement of the upper frontal zone and warm and humid air outside the subtropical high.After the precipitation,the invasion of strong cold air brought frost and cold wave weather to Ulanqab City.
文摘The El Ni?o Southern Oscillation(ENSO) is a natural phenomenon that relates to the fluctuation of temperatures over the Pacific Ocean. The ENSO significantly affects the ocean dynamics including upwelling event and coastal front. A recent study discovered the seasonal upwelling in the east coast of Peninsular Malaysia(ECPM), which is significant to the fishery industry in this region. Thus, it is vital to have a better understanding of the influence of ENSO towards the coastal upwelling and thermal front in the ECPM. The sea surface temperature(SST) data achieved from moderate resolution imaging spectroradiometer(MODIS) aboard Aqua satellite are used in this study to observe the SST changes from 2005 to 2015. However, due to cloud cover issue, a reconstruction of data set is applied to MODIS data using the data interpolating empirical orthogonal function(DINEOF) to fill in the missing gap in the dataset based on spatial and temporal available data. Besides, a wavelet transformation analysis is done to determine the temperature fluctuation throughout the time series. The DINEOF results show the coastal upwelling in the ECPM develops in July and reaches its peak in August with a clear cold water patch off the coast. There is also a significant change of SST distribution during the El Ni?o years which weaken the coastal upwelling event along the ECPM. The wavelet transformation analysis shows the highest temperature fluctuation is in 2009–2010 which indicates the strongest El Ni?o throughout the time period. It is suggested that the El Ni?o is favourable for the stratification in water column thus it is weakening the upwelling and thermal frontal zone formation in ECPM waters.
基金supported by MLTM of Korean Government Program 20052004 to S.Kwon
文摘The map expression of ＂abrupt＂ changes in lateral stratigraphic level of a thrust fault has been traditionally interpreted to be a result of the presence of （1） a lateral （or oblique） thrust-ramp, or （2） a frontal ramp with displacement gradient, and/or （3） a combination of these geometries. These geometries have been used to interpret the structures near transverse zones in fold-thrust belts （FTB）. This contribution outlines an alternative explanation that can result in the same map pattern by lateral variations in stratigraphy along the strike of a low angle thrust fault. We describe the natural example of the Leamington transverse zone, which marks the southern margin of the Pennsylvanian-Permian Oquirrh basin with genetically related lateral stratigraphic variations in the North American Sevier FTB. Thus, the observed map pattern at this zone is closely related to lateral stratigraphic variations along the strike of a horizontal fault. Even though the present-day erosional level shows the map pattern that could be interpreted as a lateral ramp, the observed structures along the Leamington zone most likely share the effects of the presence of a lateral （or oblique） ramp, lateral stratigraphic variations along the fault trace, and the displacement gradient.
文摘2021/2022年冬季,赤道中东太平洋海温偏低,导致贵州省气温偏低、降水偏多,但凝冻日数总体偏少,呈前期偏弱后期偏强的阶段性分布特征。利用贵州省84个国家气象观测站逐日观测资料、NCEP/NCAR(National Centers for Environmental Prediction/National Center for Atmospheric Research)再分析资料以及NOAA(National Oceanic and Atmospheric Administration)海温资料等,分别从海温场、高度场、风场、温度场和水汽条件等方面对凝冻阶段性特征成因进行分析。结果表明:高层南支锋区总体呈前期偏弱后期偏强,为贵州省凝冻阶段性特征提供了有利的大尺度环流背景。2022年1月26日之后,对流层低层切变线稳定维持、偏北气流异常强盛使0℃等温线南压明显。同时随着偏南气流持续增强,对流层低层水汽辐合也迅速增强,并维持低层辐合中层辐散的不稳定层结和上升运动,为贵州省凝冻阶段性特征提供了有利的水汽条件。温度场上,前期暖层较为深厚,冷空气势力前期偏弱后期偏强,为贵州省凝冻阶段性特征提供了有利的温度条件。但由于整个冬季无逆温层存在,导致3次区域性凝冻过程强度均偏弱。
文摘基于NCEP再分析资料、EC资料和常规观测资料,应用天气分析和诊断分析方法,对2016年1月广西的低温雨雪天气进行了分析,结果表明:(1)此次低温雨雪天气与阻塞高压的强而稳定密切相关。冷空气之强盛为历史所罕见,与历史同期相比,地面冷高压显著偏强,850 h Pa的0℃线明显偏南。850 h Pa华南强锋区的长时间维持,是造成此次过程的重要原因之一。(2)雨夹雪与雪的条件相似,主要是温度垂直结构存在差异;而降雪与降雨相比,温度垂直结构、云顶高度、逆温层顶部气温以及暖层的厚度、高度、强度、地面气温均有明显的区别。(3)降水相态由雨转为雪时,广西上空的锋面垂直结构有明显的变化。(4)持续而强盛的水汽输送、湿层深厚有利于阴雨、雪天气的发生及持续。相关分析结论可为广西低温雨雪冰冻预报提供技术参考。
