西宁曹家堡机场雷暴统计特征分析

基于2006—2015年西宁曹家堡机场的雷暴观测资料,从雷暴日（次）数、持续时间、初现方位、伴随天气现象和雷暴初终日特征方面对该高原机场的雷暴特征进行统计分析。结果表明,曹家堡机场年平均雷暴日数为34.7 d,主要发生在5—9月,夏季是该机场雷暴的集中爆发期;雷暴具有明显的日变化特征,集中发生在午后至夜间（16—22时）,持续时间在2 h以内;雷暴初现方位以偏西、偏北为主,偏西、偏北的对流云团发展是该机场飞行保障的关注重点;雷暴伴随天气现象以干雷暴和小阵雨为主,而少数伴有中、大阵雨的强雷暴主要发生在夏季;雷暴初终日平均间隔为173.2 d,并且初雷能充分体现该机场的典型雷暴特征。     

Reanalysis of western Pacific typhoons in 2004 with multi-satellite observations

Summary A pilot tropical cyclone reanalysis project was conducted to construct a reliable, high temporal and spatial resolution tropical cyclone dataset for selected western Pacific typhoons in summer 2004, with the application of the latest satellite observations and a 4-dimensional variational data assimilation method. Primary data used for the reanalysis include SSM/I rain rate, GOES-retrieved upper-level wind, QuikSCAT surface wind, Aqua AIRS/AMSU retrieved temperature and moisture profiles, and JTWC best track data. A regular reanalysis procedure was established and up to 12 western Pacific typhoons have been reanalyzed. The reanalysis period covers the entire life cycle of a tropical cyclone, from a few days prior to its genesis to its final decay stage. A preliminary analysis shows that the reanalysis product significantly improves typhoon intensity, structure, and track, compared to the NCEP operational final analysis. The validation of the TC structure against independent observations shows that the reanalysis reproduces well the asymmetric characteristics of TC rain bands and cloud bands. A further modeling experiment with an initial condition from the reanalysis product reveals a significant improvement in typhoon intensity forecast compared to a parallel experiment with an initial condition from the NCEP final analysis, which provides a further indication of quality of the tropical cyclone reanalysis. The reanalysis product and the raw observational data will soon be posted on the data server of the IPRC Asia-Pacific Data-Research Center () for public use.     

Prediction of the Asian-Australian Monsoon Interannual Variations with the Grid-Point Atmospheric Model of IAP LASG （GAMIL）

Seasonal prediction of Asian-Australian monsoon （A-AM） precipitation is one of the most important and challenging tasks in climate prediction. In this paper, we evaluate the performance of Grid Atmospheric Model of IAP LASG （GAMIL） on retrospective prediction of the A-AM interannual variation （IAV）, and determine to what extent GAMIL can capture the two major observed modes of A-AM rainfall IAV for the period 1979-2003. The first mode is associated with the turnabout of warming （cooling） in the Nifio 3.4 region, whereas the second mode leads the warming/cooling by about one year, signaling precursory conditions for ENSO.
We show that the GAMIL one-month lead prediction of the seasonal precipitation anomalies is primarily able to capture major features of the two observed leading modes of the IAV, with the first mode better predicted than the second. It also depicts the relationship between the first mode and ENSO rather well. On the other hand, the GAMIL has deficiencies in capturing the relationship between the second mode and ENSO. We conclude： （1） successful reproduction of the E1 Nifio-excited monsoon-ocean interaction and E1 Nifio forcing may be critical for the seasonal prediction of the A-AM rainfall IAV with the GAMIL; （2） more efforts are needed to improve the simulation not only in the Nifio 3.4 region but also in the joining area of Asia and the Indian-Pacific Ocean; （3） the selection of a one-tier system may improve the ultimate prediction of the A-AM rainfall IAV. These results offer some references for improvement of the GAMIL and associated seasonal prediction skill.     

贵州夏旱对水稻、玉米产量影响评估方法研究

提出了作物夏旱度的计算公式和作物历史灾损量的估算方法,建立了夏旱对水稻、玉米产量影响评估模型.研究指出:(1)夏旱对贵州水稻、玉米的影响区域主要集中在中部以东地区;(2)伏旱的影响区域大于初夏旱;(3)干旱对水稻的影响区域大于玉米.     

Changes in gross moist stability in the tropics under global warming

Gross moist stability, an effective static stability, in the tropics is examined in observations and model simulations. Under convective quasi-equilibrium closure, gross moist stability, a vertical integration of the vertical moist static energy gradient weighted by pressure velocity, is derived based on an approximately moist adiabatic process associated with deep convection. In climatology, gross moist stability is generally similar to the spatial distribution of mean precipitation. In global warming simulations, gross moist stability tends to increase in the tropics. It implies a more stable atmosphere, which is consistent with the weakening of tropical circulation found in climate models. Main effects, which induce the changes in gross moist stability, include the low-level moisture effect, the maximum level of convection (MLC) effect, i.e., the depth of deep convection, and the dry static energy effect associated with stratification of temperature, with the first two also found in climatology. Because of the strong cancellation between the effects of low-level moisture and dry static energy due to the moist adiabatic process of deep convection, the effect of MLC, which has been overlooked in measuring atmospheric stability, is crucial in determining the sign of changes in gross moist stability. Gross moist stability is a better index to represent changes in atmospheric stability in the tropics under global warming, compared to both dry and moist static stability.     

省级气象宽带网可靠性设计

气象业务的发展和社会需求的增长,对广域宽带网络系统提出更高要求,不但要求传输的数据量大,时效性强,而且要求其可靠性高。目前各省级气象局的宽带网可靠性设计,大都采用降级备份,无法做到双链路自动切换、无缝备份,难以满足气象业务7×24 h从不间断的实际需求,网络可靠性有待进一步提高。该文提出一种基于双向转发检测 (BFD) 和策略路由技术的网络可靠性设计方案,应用该方案不仅使网络结构和带宽有大幅提升,还能实现业务分流、链路冗余和故障自动切换,提高气象宽带网的可靠性水平。该方案经严格测试后,已依托广东省气象宽带网得以实现并投入业务运行,效果良好。同时,该设计对其他省级气象网络建设有一定参考价值。     

中国城市固体废弃物甲烷排放研究

The greenhouse effect of methane (CH4) is only inferior to that of carbon dioxide (CO2). As an important anthropogenic emission source, the calculation of the emission amount of CH4 from waste treatment in landfills plays an important role in compiling greenhouse gases inventory and in estimating the climate change effects caused by increasing of greenhouse gases. Based on the previous work, and according to the sampling and analysis on municipal solid waste (MSW) in typical cities, the degradable organic carbon (DOC) percentile was identified in typical cities in recent years. According to the IPCC greenhouse gases inventory guideline and default method of CH4 emission from MSW landfills, and in light of MSW managing situation in different regions, the amount of CH4 emission was calculated. The results show that the amount of CH4 emission decreases geographically from east to west and it increases temporally from 1994 to 2004 in China.     

关于台风"飞燕"(0102)若干问题的探讨

本文讨论了台风"飞燕"路径、结构等方面问题。台风"飞燕"登陆前先后受地形低压和热带云团影响,分别出现右折和左折。在结构上具有尺度小、强度强和椭圆形眼的特点,椭圆形的眼区使沿海台站在台风来临前3~9 h内气压明显上升。狂风暴雨出现在台风中心及其右侧地区,灾害主要由猛烈阵风和暴潮造成。     

综合评价方法在水质评价应用中的比较研究

以黄河某取水口监测点19981999年的水质为评价对象,利用灰色关联分析法、模糊综合评价法和物元分析法分别进行了综合评价,结果表明,模糊综合评价和物元分析法的评价结果一致,"中心化"灰色关联法评价结果与上述两方法的评价结果一致.