强电场探空仪及雷雨云电场探测结果的分析

用尖端导线作感应元件,用调频—调幅体制传递讯息,制成了雷雨云中的电场探空仪。频率调制器由一只2П1П管组成,另一只2П1П管组成发射频率为85兆赫的发射机。地面接收设备采用了一定的抗干扰电路,能消除非当顶闪电引起的干扰,使用该仪器进行了五次探测(结果见图9),并对深测结果作了初步分析。     

《AHDM4.1》系统的缺陷及处理方法

总结分析了《AHDM4．1)系统存在的缺陷，改正《AHDM4．1》系统运行结果的错误，避免因软件缺陷造成的报文及报表错误，以提高地面气象测报质量。     

苏联天气预报的情况和问题

编注:苏联水文气象中心天气室负责人Х.П.帕柯香在《自然》杂志上发表了一篇关于《天气预报的成绩和困难》的文章,概括了苏修天气预报的情况和对长期天气预报的一些看法,现介绍如下,以供了解与分析批判。     

使用L波段雷达放球软件和数据处理软件的几点技巧

通过对L波段雷达放球软件和处理软件在使用过程中易出现问题的环节进行深入细致的分析，并结合近两年的使用实践，对如何正确使用该软件和规避使用过程中出现的错误，提出了一些见解．     

导致气象报文编发错误的原因分析及避免对策

介绍9210工程业务化运行以来气象报文的主要编发错误，包括编报错误和传输错误，分析常见错误的特点，并提出避免错误的几点对策。     

Ｒｉｃｉａｎ Ｎａｋａｇｉｍｉ信道中正交空时分组码的近似性能分析

在Ｒｉｃｉａｎ Ｎａｋａｇａｍｉ信道中,正交空时分组码在ＭＰＳＫ和ＭＱＡＭ调制下符号错误概率已有精确的闭式表达式．这些结果由复杂的多元超几何函数表示．为了降低理论分析的复杂度,采用梯形法理论进行近似性能分析,即在ＭＰＳＫ和ＭＱＡＭ调制下,将两者的平均符号错误概率的积分表达式进行分段,每个分段区间用梯形取代,并给出了其符号错误概率的近似封闭表达式．仿真结果表明,即使在较小的分段数目下,采用梯形法 的近似性能曲线与精确性能曲线仍吻合很好．     

编发气象旬（月）报常见错误分析

分析了近年来广西气象台站在编发气象旬（月）报时出现的７种常见错误，并提出了减少编发错误的３项措施。     

兴义雷达敏视达产品冰雹识别优化处理模式

通过对兴义雷达多次冰雹雷雨天气过程敏视达导出产品的分析研究，采用多因子判别的方法建立冰雹识别函数。根据实际观测到的若干个例统计结果，确定冰雹识别函数临界判别值歹。当y〉^-y时判别为冰雹云，y〈^-y则为雷雨云。通过12次实际应用试验，只有一次识别错误，正确识别率达91．7％，表明该模式实用性强，可直接在业务中使用。     

AWOS2000通讯冲突问题的探讨

本文讨论了AWOS2000在运用过程中因系统软件配置错误，致使两台DPU同时共同一条Polling总线，从而在DPU通讯管理与场地传感器ISI之间产生了通讯部突，在查找软件配置问题的同时，仔细分析了导致通讯冲突的几种原因，籍以向其他A－WOS2000用户提供一种分析和解决类似问题的途径和方法。     

对云观测问题的分析

检查我省气象台站地面气象观测记录，发现积云性层积云（Sccug）记录越来越多，而积雨云（Cbcap）的云量记录越来越少，有些站几乎是有低云便有Sccug。为此，笔者对台站的云天记录进行一了分析，并进行了跟班，发现部分云状、云量的记录是误记的。特对此进行分析。1多记Sccug的情况和原因（1）在夏天和秋天，因热力作用而形成的积雨云（以下简称Cb云），误把其底部阴暗混乱部分单独记为Sccug和Fc。即把一种Cbcap，误记为Cbcap、Sccug和Fc三种云，多记Sccug少记了Cbcap。造成这种错误的主要原因，是观测员对Cb云定义理解的错误，认为Cb…     

CHARACTERISTICS AND TRENDS OF CLIMATIC EXTREMES IN CHINA DURING 1959–2014

The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.     

Revisiting the Concentration Observations and Source Apportionment of Atmospheric Ammonia

正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on     

LOW-FREQUENCY CIRCULATION AND EXTENDED-RANGE FORECAST IN CONNECTION WITH AUTUMN EXTREME HEAVY RAINFALL PROCESS IN HAINAN

Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d.     

AN ATTRIBUTION ANALYSIS OF CHANGES IN POTENTIAL EVAPOTRANSPIRATION IN THE BEIJING–TIANJIN–HEBEI REGION UNDER CLIMATE CHANGE

Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region.     

ANALYSIS OF “BIMODAL PATTERN” STORM ACTIVITY CHARACTERISTICS OF THE BAY OF BENGAL

Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms.     

Information for Authors

正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography.     

Information for Authors

AIMS AND SCOPE
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome.     

Information for Authors

AIMS AND SCOPE Atmospheric and Oceanic Science Letters （AOSL） pub- lishes short research letters on all disciplines of the atmos- phere sciences and physical oceanography. Contributions from all over the world are welcome.     

INFORMATION FOR AUTHORS

正Aims Scope Advances in Atmospheric Sciences(AAS)is an international journal on the dynamics,physics,and chemistry of the atmosphere and ocean with papers across the full range of the atmospheric sciences,co-published bimonthly by Science Press and Springer.The journal includes Articles,Note and Correspondence,and Letters.Contributions from all over the world are welcome.