多普勒声雷达对化音地区风场结构探测的初步分析

本文利用1990年8月多普勒声雷达在“HEIFE”区化音站探测的资料,对该地区的PBL结构进行了初步分析。结果表明,用声雷达回波强度的双对数廓线确定大气边界层高度仍不失为一有效的方法。大气边界层高度演变过程的特点是:白天对流层边界发展较快,但维持时间较短;而夜间稳定边界层维持时间较长,且在其发展较高时,在近地层又发展出一个新的稳定层结,呈现多层次的SBL结构。ML内垂直风速方差的归一化结果与Lenschow大致相同。另外,在一次冷锋过境天气背景下风场出现低空急流结构。     

近50年汕头市气候演变特征分析

本文运用统计学方法对汕头市近50多年气象资料进行气候演变特征分析,得到了一些对本地区年平均气温和年总降水量有预测意义的结果。     

Connection of the stratospheric QBO with global atmospheric general circulation and tropical SST. Part II: interdecadal variations

The interdecadal variation of the association of the stratospheric quasi-biennial oscillation (QBO) with tropical sea surface temperature (SST) anomalies (SSTA) and with the general circulation in the troposphere and lower stratosphere is examined using the ERA40 and NCEP/NCAR reanalyses, as well as other observation-based analyses. It is found that the relationship between the QBO and tropical SSTA changed once around 1978–1980, and again in 1993–1995. During 1966–1974, negative correlation between the QBO and NINO3.4 indices reached its maximum when the NINO3.4 index lagged the QBO by less than 6?months. Correspondingly, the positive correlations were observed when the NINO3.4 index led the QBO by about 11–13?months or lagged by about 12–18?months. However, maximum negative correlations were shifted from the NINO3.4 index lagging the QBO by about 0–6?months during 1966–1974 to about 3–12?months during 1985–1992. During 1975–1979, both the negative and positive correlations were relatively small and the QBO and ENSO were practically unrelated to each other. The phase-based QBO life cycle composites also confirm that, on average, there are two phase (6–7?months) delay in the evolution of the QBO-associated anomalous Walker circulation, tropical SST, atmospheric stability, and troposphere and lower stratosphere temperature anomalies during 1980–1994 in comparison with those in 1957–1978. The interdecadal variation of the association between the QBO and the troposphere variability may be largely due to the characteristic change of El Ni?o-Southern Oscillation. The irregularity of the QBO may play a secondary role in the interdecadal variation of the association.     

Decreasing trend of sunshine hours and related driving forces in Southwestern China

Total hours of sunshine are one of the most important factors affecting climate and environment, and its long-term variation is of much concern in climate studies. Trends of temporal and spatial patterns in sunshine hours and related climatic factors over southwestern China are evaluated for the period 1961–2009 based on data from 111 standard meteorological stations. The results showed that southwestern China is experiencing a statistical decrease of sunshine hours, at the rate of 31.9 h/10a during 1961–2009. The decline was particularly strong in summer, whereas it is nonsignificant in winter. Spatially, statistically significant decreases of sunshine hours mainly occurred in lower altitude regions, especially in the Sichuan basin and Guizhou plateau. Sunshine hours have a high correlation with wind speed, relative humidity, precipitation, cloud cover, surface downwards solar radiation flux, and cloud water content, with wind speed showing the strongest relationship to sunshine hours, implicit in the close correlation (temporally and spatially) between the two variables. Changing water vapor and cloud cover influence sunshine hours in southwestern China. In addition, the increased surface downwards solar radiation flux also made some contribution to a rise of sunshine hours during 1991–2009. The larger decreasing trends of sunshine hours at urban stations than rural stations may reflect the effect of urbanization on sunshine hours. Variations are dominated by the comprehensive functions of multiple factors owing to the complex nature of effects on sunshine hours.     

基于手机邮箱监控天气雷达运行状态的方法

介绍了一种新的短信报警方法,通过巧妙应用中国移动的139邮箱业务,同样能完成对雷达状态的监控,并详细阐述了该方法的原理,最后对两种方法的优劣势进行了对比分析,为台站在设计监控软件时能有多种选择。     

南京降水氢氧同位素监测特征

基于2018年7月—2019年6月南京降水同位素观测数据和中国气象局气象观测数据,研究南京降水稳定同位素组成的变化特征,对比热带气旋降水、梅雨降水和其他降水的降水同位素组成特征,研究降水同位素组成与热带气旋移动路径关系。结果表明：南京降水氧同位素组成(δ18O)和氢同位素组成(δ2H)的变化范围分别为-16.3‰~4.0‰和-103.0‰~32.9‰,雨季降水氢氧同位素组成相对贫化,非雨季相对富集;降水氘盈余的降水加权平均值为15.5‰,表明南京降水受陆面过程影响大。从降水量权重看,热带气旋降水和梅雨降水强度大,降水氢氧同位素组成严重贫化;其他降水的强度相对较弱,降水氢氧同位素组成比较富集;受水汽源地和陆面循环等过程的综合影响,热带气旋降水氘盈余小于全球平均值(10‰),梅雨降水氘盈余略高于全球平均值,其他降水氘盈余远高于全球平均值。登陆前仅在海洋上移动的热带气旋,降水氘盈余维持在7.5‰~8.6‰,但二次登陆的热带气旋降水氘盈余远大于10‰,可能是受到陆地蒸散过程的影响。     

国务院气象数据服务系统的升级改造

为了更好地保障国务院办公厅接收中国气象局提供的各类气象数据,解决旧有系统存在的问题,对现有国务院气象数据服务系统进行升级改造。全新开发的数据收集发送功能,解决了现有系统无法进行非法文件过滤和配置灵活性问题;升级现有的监视系统,使新系统满足业务需要的检索、报警、时效计算等功能;扩充的补调下载功能更加贴近操作员的使用习惯。改造后的系统通过数据传输与时效监视功能的分离和程序的改进,增强了传输可靠性和时效性,同时能够为未来业务应用扩展提供支持。经过实际业务测试,系统运行稳定,并为2011年国务院汛期服务提供了有效支撑。     

新疆新一代区域数值预报业务系统客观检验分析

运用MET检验工具,对新一代乌鲁木齐区域数值预报业务系统(RMAPS-CA)和目前业务运行系统(DOGRAFS)各季节业务模式预报性能进行对比检验分析.结果表明,相较于DOGRAFS系统,RMAPS-CA系统具有更高的空间分辨率和预报检验评分,预报能力明显提高.具体表现为:(1)对于高空要素预报,RMAPS-CA系统温...     

江西省2018年秋冬连阴雨天气异常特征及成因

2018年11月1日—2019年3月10日江西省出现区域性连续阴雨寡照天气,文中利用实时检测、历史同期数据和连阴雨极端天气气候事件指标,结合NCEP/NCAR逐日再分析资料和NOAA全球海表温度资料,对这次区域连阴雨天气的异常气候特征和成因进行分析.结果表明:1)此次区域连阴雨天气具有阴雨、连阴雨日数多,累计雨量大、雨日多,日照时数少、无日照和连续无日照日数多等特点.2)连阴雨天气期间,北半球环流形势异常,欧亚中高纬呈"两脊两槽"型环流控制,有利于冷空气入侵我国南方地区;西太平洋副热带高压较常年偏强,西伸脊点偏西,脊线位置偏北,异常西南风水汽输送为持续阴雨天气提供了丰沛的水汽条件并与南下冷空气在江淮至江南地区交汇,造成江西降水异常偏多.3)赤道中东太平洋海温异常对江西秋冬季降水量和阴雨日数有重要影响;2018年江西秋冬季降水表现出对典型El Nino事件的响应,在El Nino的影响下,2018年江西省秋冬季降水量和阴雨日数偏多.