豫西龙卷风的时空分布特征及灾情分析

对豫西1949-2008年龙卷风的有关史料调查分析表明:豫西(多丘陵山地)发生龙卷风的概率相对全省较低,富士达分级F0级17次,F1级12次,F2级仅有2次;90年代龙卷风发生较多,主要集中在6-8月,一天之中多出现在下午至傍晚;风力一般都在10级以上,持续时间8-60 min不等,平均25 min.豫西的龙卷风各有2个县(市)发生过4次和3次,7个县(市)发生过2次,11个县(市)发生过1次,其余33个县(市)没有龙卷风的相关记录.在豫西只有相对比较开阔、平坦的地域才可能促生龙卷风.     

大气污染物SOx输送方程的尺度分析

文中用量纲分析方法分析了控制大气污染物输送方程的动力学特性。提出了 6种反映大气污染物输送过程中各种动力、物理和化学过程相对重要性的动力学参数。并以硫氧化物为例进行了各参数量级大小分析 ,尤其对 3种起汇作用 (去除机理 )的机理 (化学转化、干沉降和湿清除 )在不同尺度大气污染过程中的作用进行了详细分析。结果表明 :在一般情况下 ,SO2 的气相化学作用小于干沉降和湿清除的作用 ;干沉降作用很依赖于模式最底层厚度的选取 ;在有降雨时湿清除作用一般较大。文中还对大气污染物SOx 输送方程各项特征量的量级作了分析对比 ,得出了控制不同尺度大气污染物输送过程的零级近似方程和一级近似方程 ,并指出了这些方程的基本特征     

区域气候模式RegCM3应用研究综述

回顾了区域气候模式RegCM的发展历史,并对最近推出的RegCM3模式目前的应用进展情况进行了分类总结,同时讨论了今后的研究方向和其中存在的不足。     

气候变化对中国农业生产影响研究展望

综述了气候变化背景下中国农业气候资源、农业气象灾害(干旱、洪涝、高温热浪、低温灾害)和农业病虫害的变化趋势与规律,从农业生产潜力变化、作物种植制度变化和作物品质变化等方面阐明了气候变化对中国农业生产的影响事实,分析了气候变化对中国农业生产的可能影响和中国农业生产适应气候变化的对策措施。在此基础上,针对气候变化背景下中国气候资源的时空分布特点及农业生产出现的新情况、新问题,指出了当前中国关于气候变化对农业影响研究存在的不足,提出了未来气候变化对中国农业生产影响研究需要重视的方面,为确保气候变化背景下中国的农业生产安全及粮食安全提供决策支持。     

制作汛期降水集成预报的分区权重法

该文提出一种不受历史预报档案资料多少限制的集成预报方法。这个方法的基本思想是以各种不同预报的历史评分资料为基础,确定各个预报方法的权重。根据若干原则设计了16种预报方案。计算结果表明,这个方法具有较高的准确度和可行性,可以用于业务预报。     

Impact of the thermal state of the tropical western Pacific on onset date and process of the South China Sea summer monsoon

Since the early or late onset of the South China Sea summer monsoon （SCSM） has a large impact on summer monsoon rainfall in East Asia, the mechanism and process of early or late onset of the SCSM are an worthy issue to study. In this paper, the results analyzed by using the observed data show that the onset date and process of the SCSM are closely associated with the thermal state of the tropical western Pacific in spring. When the tropical western Pacific is in a warming state in spring, the western Pacific subtropical high shifts eastward, and twin cyclones are early caused over the Bay of Bengal and Sumatra before the SCSM onset. In this case, the cyclonic circulation located over the Bay of Bengal can be early intensified and become into a strong trough. Thus, the westerly flow and convective activity can be intensified over Sumatra, the Indo-China Peninsula and the South China Sea （SCS） in mid-May. This leads to early onset of the SCSM. In contrast, when the tropical western Pacific is in a cooling state, the western Pacific subtropical high anomalously shifts westward, the twin cyclones located over the equatorial eastern Indian Ocean and Sumatra are weakened, and the twin anomaly anticyclones appear over these regions from late April to mid-May. Thus, the westerly flow and convective activity cannot be early intensified over the Indo-China Peninsula and the SCS. Only when the western Pacific subtropical high moves eastward, the weak trough located over the Bay of Bengal can be intensified and become into a strong trough, the strong southwesterly wind and convective activity can be intensified over the Indo-China Peninsula and the SCS in late May. Thus, this leads to late onset of the SCSM. Moreover, in this paper, the influencing mechanism of the thermal state of the tropical western Pacific on the SCSM onset is discussed further from the Walker circulation anomalies in the different thermal states of the tropical western Pacific.     

Regional differences in surface sensible and latent heat fluxes in China

This study documents the variability of surface sensible and latent heat fluxes in five regions of China (Northwest China, the Tibetan Plateau, Northeast China, North China, and Southeast China) using the ERA-40 reanalysis for the years 1960–2000. The surface sensible and latent heat flux variations are remarkably different in Northwest and Southeast China. The seasonal variation of the surface sensible heat fluxes is largest in Northwest China and smallest in Southeast China. In contrast, the seasonal variation in latent heat flux is largest in Southeast China and smallest in Northwest China. The interdecadal variation of surface sensible and surface latent heat fluxes strongly depends on both the region and season. The trends in surface sensible and latent heat fluxes in all four seasons are mainly caused by variations in both the land–air temperature difference and in the specific humidity. There is also a limited contribution of wind speed in some regions, depending on the season.     

贵州春季冰雹天气过程个例分析

利用天气形势及各种物理量值、卫星云图和多普勒雷达资料,分析了2009年4月11日傍晚到夜间发生在贵州省中部、西部地区的冰雹天气过程成因,结果发现:高原东移低涡是这次过程的主要影响系统;高层冷平流、低层暖平流,增强了气层的不稳定性;0℃层高度(600 hPa)和-20℃层高度(400 hPa)有利于冰雹生长.强对流天气发...     

鄂西北夏季对流降水回波特征的研究

该文通过对鄂西北1995～1999年6～9月273个对流回波个例进行统计分析，得出生成对流云的主要天气背景为西风低槽过境和副高外围的影响。对流云回波出现频率6、9月较少，7～8月较多。当地地形对对流云活动具有促进生成、约束移动、抬升加强等作用。对流云可分为单体、多单体、超级单体和混合云中对流等种类。6、9月对流云平均的生命时间较短，回波强度、顶高和强回波区顶高较低。相反，7～8月对流云回波特征值较高     

月山地区铜成矿作用的同位素地球化学研究

月山地区矽卡岩型和热液脉型铜矿床氢、氧、硫、铅、和硅笔同位素组成及演化的特征显示，区内具工业价值铜矿的成矿物质主要由闪长质岩浆经熔－流分离作用提供，主要成 在放阶段的成矿热液以岩浆水为主，地矿中晚期大气降水混入量逐渐增多，三叠系和部分前三叠系提供了部分硫源和少量成矿物质。