人工增雨可播区域自动选择方法研究

综合利用雷达、卫星、数值模式产品和探空等各种不同类型、不同分辨率的资料,使用计算机软件技术自动选择人工增雨可播区域.该方法把整个区域分解为若干小块,形成小块矩阵.通过处理不同分辨率资料,使之与一定小块之间建立相关,利用这些资料综合判断小块可播性.然后把小块矩阵看作一个稀疏矩阵,采用正交链表存储方式,使用相邻搜索算法,自动找出所有可播区域.文中描述了该方法的实现算法以及采用的相应数据结构和存储结构,并简单地分析了一个应用个例.     

上海浦东地区"梅雨期"降水及其多尺度时频特征

提出了浦东地区"梅雨期"降水的概念.在此基础上,利用小波变换分析了浦东地区"梅雨期"降水的多尺度时频特征及其突变现象.结果表明:浦东地区6月1日-7月10日期间的降水序列能更加客观地反映该地区春末夏初这一特殊的"梅雨期"降水量的实际状况;浦东地区"梅雨期"降水存在准2a和10～20a的主要振荡周期;利用小波逆变换重构的不同振荡周期的时间序列能更好地反映原序列的主要周期振荡特征及其趋势信息.     

利用雷达资料选择可播区域

利用雷达回波资料,使用分块法,把整个回波区域划分为小块矩阵,确定各小块可播性,然后把小块矩阵作为稀疏矩阵来处理,采用正交链表存储方式,使用相邻搜索算法,自动找出所有可播区域,并应用c++语言描述该方法的实现算法以及采用的相应数据结构和存储结构,从而解决了使用雷达资料选择可播区的问题.     

DBASEⅢ窗口菜单源程序自动生成

本文介绍DBASEⅡ窗口式菜单源程序自动生成方法。使用该方程能方便,快速地实现菜单编程自动化。     

利用三次卷积方法实现新一代天气雷达产品电视播出

针对地市级电视天气预报节目中雷达网制作环节存在的问题,使用VB编程丁具,读取单站新一代天气雷达产品的第19类数据(反射率因子),利用三次卷积插值算法进行放缩,生成可适用绝大多数非编软件播出的带有Alpha通道的TGA文件序列,并且可以通过Alpha通道叠加背景图片或动态视频,实现雷达产品在电视天气预报节目中播出.实践证明,三次卷积插值方法不仅内插精度较高、图像的颜色连续,所得图像质量较其它插值方法明显提高,符合播出标准,而且还能较好地保留图像的高频成分.     

利用雷达资料选择可播区域

利用雷达回波资料,使用分块法,把整个回波区域划分为小块矩阵,确定各小块可播性,然后把小块矩阵作为稀疏矩阵来处理,采用正交链表存储方式,使用相邻搜索算法,自动找出所有可播区域,并应用c 语言描述该方法的实现算法以及采用的相应数据结构和存储结构,从而解决了使用雷达资料选择可播区的问题。     

时空序列预测误差的敏感性试验分析

利用33模Lorenz系统得到的"理想"混沌时空序列,作为时空混沌序列"发生器".通过状态空间重构,建立"场时间序列"局域近似预测模型,对资料空间分辨率,资料的长度、噪音,以及模型的参数选取等因素进行敏感性试验分析,了解时空混沌序列预测中误差产生和增长的一些影响因素.得到以下初步结论:对于理想混沌时空序列(33模Lorenz系统)而言,与系统相适应的资料空间分辨率和较长的资料长度都将会提高预测精度;可预报时效与资料长度之间近似服从指数关系.另外,在建立预测模型时,适当的邻近点数目,以及采用二阶映射关系和迭代法都可以有效地改善预测精度.对于加入噪音的混沌时间序列,通过"场时间序列"的局域近似方法和4阶自回归方法的预测试验的对比表明,前者显示了更强的抗"干扰"能力.以上结论可以有分析地应用于短期气候预测中.     

北京奥运气象服务产品制作系统设计与实现

介绍了专用于2008年北京奥运会、残奥会气象保障任务的奥运气象信息服务系统(OMIS)的核心分系统之一——"北京奥运气象服务产品制作系统"的设计思路与实现技术。该系统根据北京奥运气象服务的开放性、稳定性、灵活性等高标准要求,首次在奥运气象服务中引入TeX技术,并结合产品模版以及关系数据库等技术策略,构建一套稳定、灵活、针对性强的奥运气象服务产品生成的解决方案。该系统使用C++STL开发,适用于Linux,Windows平台,能快速实现数十种气象服务预报产品的制作,并可根据奥运会、残奥会需求的变化灵活修改以生成新的服务产品。该系统作为中国气象局北京奥运服务中心的"奥运气象信息服务系统"的关键部分,在北京奥运会、残奥会期间运行稳定,前后共产生数万个气象服务产品,圆满完成北京奥运气象服务保障任务。     

决策树技术分析气象因子对电力负荷预测的影响

基于决策树技术,对气象因子和日电力负荷的最高、最低值、平均值进行联合建模,量化气象因子对电力负荷的影响,从而确立一种有效的基于气象因子的短期电力负荷预测方法,用以生成日特征负荷决策树预测模型.通过该模型,结合预测日的气象、属性(日期、节日等)等信息,可进行日特征负荷的预测.预测结果表明,该模型具有自动化程度高、预测结果准确率高的特性.以河北省保定市气象数据和电力负荷数据为例进行了训练和预测,研究结果证明这种方法能较大地提高日电力负荷预测的精度.     

自动站实况图形监控及灾害预警程序的设计

通过对Surfer软件功能深入研究发现,Surfer软件具有较完美的数据处理和图形显示功能,且Surfer与VB编程语言之间可实现ActiveX自动化连接.介绍的程序设计思路为将Surfer强大的绘图功能与VB编制交互程序界面的优势相结合,实时读取自动站观测数据并生成Surfer绘图数据文件,调用Surfer软件的绘图功能,实现自动站雨量、温度和风向风速等资料的填图、等值线绘图及色彩填充等,并直观地显示与输出这些图形.该程序可实现自动站资料查询和运行异常情况监测及区域灾害情况预警信息自动发布等.     

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.     

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.     

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.     

Could the Recent Taal Volcano Eruption Trigger an El Ni?o and Lead to Eurasian Warming?

正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment.     

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     

COMPARATIVE ANALYSIS OF VARIOUS DATA OF AIR–SEA TEMPERATURE DIFFERENCE AND ITS VARIATION ACROSS SOUTH CHINA SEA IN THE PAST 35 YEARS

Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.     

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. Contributions from all over the world are welcome.SUBMISSIONAll submitted     

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.