分布式开放型多普勒天气雷达产品系统设计

随着我国多普勒天气雷达网建设的深入发展, 雷达气象产品系统开发和资料应用越来越迫切。文章介绍了开放软件系统模型, 分析了新一代天气雷达特点和发展需求。结合新一代天气雷达网和我国气象业务网发展状况, 提出和研究了可供新一代天气雷达使用的开放系统的分布式业务模式, 研究和设计了雷达气象产品开放系统的结构和运行方式。文中的分布式开放型雷达产品系统的结构和模型, 对其他类业务和科研系统的开发和发展具有参考价值。     

利用APSIM模型评估播期和种植密度对关中玉米气候生产力的影响

以陕西关中为研究区域,利用杨凌和长武的玉米试验数据校正和验证了APSIM模型,结合1971—2010年的气象数据,模拟了不同播期和种植密度情形下的玉米潜在生产力。结果显示:APSIM模型在关中地区适应性较好。夏玉米潜在产量和雨养潜在产量分别为8756和4236 kg/hm²,春玉米分别为13138和6163 kg/hm²,通过灌溉最高可分别增产52%和53%,而降雨量是制约该地区玉米生产的主要气候因子。适当推迟播期和提高种植密度可以有效提高玉米潜在产量和水分利用效率(water use efficiency,WUE)。其中,夏玉米潜在产量和雨养潜在产量最高可分别提高20.0%和24.2%,春玉米可分别提高21.7%和22.8%;夏玉米潜在WUE和雨养潜在WUE可分别提高22.7%和20.8%,春玉米可分别提高14.4%和20.0%。因此,同时优化播期和种植密度可以有效提高关中玉米的气候生产潜力。     

气象多普勒雷达测试技术介绍

本文主要通过详细的图示和相关的计算公式,以DW SR 2500C/K为例,介绍了进口多普勒气象雷达的测试和计算,其中包括脉冲宽度、发射频率、脉冲重复频率、峰值功率、接收机信号线性性和动态范围和最小可探测信号的测量等。对于国产气象多普勒雷达的测试从原理和方法上具有参考和充实作用,有普遍的实用价值。     

高层大气温度和高度场异常对我国地面气温和降水的影响

用SVD方法分析了NCEP／NCAR 1958—1997年再分析资料中月平均的300hPa温度(下称“高层温度”)和100hPa高度(下称“高层高度”)距平场与中国160个测站的月平均地表气温(下称“我国温度”)和月降水距平场的时滞和空间耦合关系,讨论了高层温度和高度距平场的空间分布和时间演变对我国气温和降水异常的影响。结果表明,高层温度和高度距平场的整体空间分布形势对中国气温和降水的影响明显,不同关键区的高层温度和高度距平场对我国不同区域的气温和降水异常有影响,具有明显的区域耦合特征。伊朗高原和青藏高原及其以南的热带低纬地区是高层温度和高度场的关键区。高层温度场对我国气温场和降水场的影响主要表现为年际变化,而高层高度场的影响主要表现为年代际变化。我国长江和黄河流域、华南和江南地区是受高层温度场和高度场异常影响最明显的地区。     

长江三角洲地区人类活动与气候环境变化

使用长三角地区1961年以来的气温、降水、日照等气象资料和土地、人口、能源等社会经济资料,分析了它们的年际变化趋势和演变特征。指出长三角地区气候变化和土地利用变化体现了自然和人类活动的影响。城市化和工业化促进了长三角地区经济的高速发展,但同时也引起了人口和能源消耗剧增等问题,从而加剧了长三角地区的大气污染和气候环境变化。     

台风发生发展和变性研究的进展

台风的发生发展和变性对于有关研究和天气预报十分重要。本文简要介绍台风的发生发展的理论和变性研究的进展,可供台风研究和预报参考。     

江淮以南地区暴雨和强降水的中尺度天气动力学研究进展

经过新中国成立以来多次中尺度天气试验研究,江淮以南地区暴雨和强降水的中尺度天气动力学研究取得长足进展。其进展主要体现在两个方面:一是用较高分辨率的观测资料(包括地面和高空探测的加密观测以及卫星和雷达的观测)对形成暴雨和强降水的中尺度天气系统的结构特征和生命史过程建立了天气学概念模型,特别是对暴雨和强降水有重要影响的α中尺度和β中尺度对流系统,建立了观测个例的中尺度物理模型;二是探索了暴雨和强降水的动力学和热力学的物理机制,为精细化数值模式的设计提供了理论支撑,为灾害性天气预测预警提供了技术支持。本文在以往暴雨和强降水研究的基础上,着重对暴雨和强降水的中尺度天气科学试验、江淮以南地区暴雨和强降水发生主要区域的中尺度天气动力学研究进行了概述。     

气候平均值和方差的次序统计估计量

给出了估计样本平均值和方差的次序统计量——中值、伪标准差、加权均值、加权标准差的数学描述,对其统计估计性能——一致性、无偏性和有效性进行了模拟评估,评估分析结果表明:这些次序统计量具有一致性和无偏性,有效性在正态总体下低于传统统计量,在偏态总体下接近或超过传统统计量,加权均值和加权标准差的有效性高于中值和伪标准差,接近传统统计量.模拟和实例均表明,与传统的均值和标准差估计量相比,当资料存在特异值时,次序统计量具有明显的优越性.     

El Ni?o和La Ni?a冬季增强型和减弱型及其对中国夏季旱涝的影响

根据El Ni?o和La Ni?a发生以后冬季赤道东太平洋海温距平的月际差定义了El Ni?o和La Ni?a冬季增强型和冬季减弱型, 讨论了El Ni?o和La Ni?a冬季增强型和减弱型冬、春、夏季大气环流、东亚季风及我国夏季降水和旱涝分布的特征.我国夏季降水和旱涝有明显差异的四种不同分布型可能与冬季所处ENSO循环的不同阶段以及大气环流和东亚季风对它的不同响应有关.提出了从El Ni?o和La Ni?a冬季不同型→大气环流和东亚季风→我国夏季降水和旱涝分布型的物理统计概念模型.     

加快黑龙江省气候资源探测和保护立法的建议

气候资源探测和保护,是气象工作的重要组成部分,是各级政府、气象主管机构的主要职能之一。当前,随着全球气候变暖．气候资源探测和保护引起了全社会的关注,特别是当气候资源成为一种清洁可再生能源被开发利用时,吸引了越来越多的经济社会组织和利益集团参与介入,给气候资源探测和保护工作带来了许多新的问题和困难,其中一些急难问题亟需地方人大常委会从实际出发,通过立法加以法律规范,为依法探测和保护气候资源提供依据和保障。为此,本文根据上位法规定,对加快黑龙江省气候资源探测和保护立法工作．提出以下几点建议：     

广西气候与全球气候变化趋势异同点

用近百年的气温、降水量实测数据,对广西与全球、全国的气候变化的异同进行了统计分析,结果表明：广西的气候变化与全球气候变化的趋势基本一致,但全球气候变暖并未在广西得到反映。     

贺州市春季降水旱涝分析及灾变预测

利用贺州市四站1965~2004年春季降水资料,运用z指数和区域旱涝指数对贺州地区春季旱涝情况进行计算分类,并对重旱涝典型年份500hPa环流特征量和4月平均环流场展开分析,发现:贺州地区春季极易发生局部旱涝灾情,90年代以来重旱涝年份出现频率明显增大;在重旱年副高强度强,西伸脊点明显偏西,南支槽偏西偏弱,极涡中心偏东,亚洲中高纬高度偏低,在重涝年则相反。同时,通过建立GM(1,1)灾变预报模型,以重旱涝年份出现顺序为原始序列作模拟预报,其结果具有较好的应用价值。     

On The Temperature-Humidity Correlation And Similarity

The correlation coefficient between temperature and specific humidity (r_Tq) is considered. A brief literature review as well as experimental data reveals that there is evidence that the eddy diffusivities for heat and water vapour are not equal if |r_Tq| 1. Several conditions under which this can occur are discussed. It is concluded that if non-local effects are of the same order as local effects T and q will behave in a non-similar fashion. Moreover, it is shown that if |r_Tq| = 1, temperature and specific humidity both will obey Monin–Obukhov similarity. In addition, based on that derivation, a new method is presented to determine the Bowen ratio from the T - q correlation. A first test of this new Bowen ratio regression method is presented. It is recommended to use r_Tq as a diagnostic tool to judge whether T-q similarity holds.     

北海市气候资源的开发利用及防灾减灾对策

对北海市气候资源的开发利用及气候灾害防灾减灾对策进行分析,为北海市乃至广西的可持续性发展提供了科学依据.     

A Regional, Multi-sectoral And Integrated Assessment Of The Impacts Of Climate And Socio-economic Change In The Uk

Policy makers and stakeholders are increasingly demanding impact assessments which produce policy-relevant guidance on the local impacts of global climate change. The ‘Regional Climate Change Impact and Response Studies in East Anglia and North West England’ (RegIS) study developed a methodology for stakeholder-led, regional climate change impact assessment that explicitly evaluated local and regional (sub-national) scale impacts and adaptation options, and cross-sectoral interactions between four major sectors driving landscape change (agriculture, biodiversity, coasts and floodplains and water resources). The ‘Drivers-Pressure-State-Impact-Response’ (DPSIR) approach provided a structure for linking the modelling and scenario techniques. A 5 × 5 km grid was chosen for numerical modelling input (climate and socio-economic scenarios) and output, as a compromise between the climate scenario resolution (10 × 10 km) and the detailed spatial resolution output desired by stakeholders. Fundamental methodological issues have been raised by RegIS which reflect the difficulty of multi-sectoral modelling studies at local scales. In particular, the role of scenarios, error propagation in linked models, model validity, transparency and transportability as well as the use of integrated assessment to evaluate adaptation options to climate change are examined. Integrated assessments will provide new insights which will compliment those derived by more detailed sectoral assessments.     

Theory And Measurements For Turbulence Spectra And Variances In The Atmospheric Neutral Surface Layer

Predictions from a new theory for high Reynolds number turbulent boundary layers during near-neutral conditions are shown to agree well with measurements of atmospheric surface-layer variances and spectra. The theory suggests surface-layer turbulence is determined by detached eddies that largely originate in the shearing motion immediately above the surface layer; as they descend into this layer, they are strongly distorted by the local shear and impinge onto the surface. Because the origin of these eddies is non-local, they are similar to those described in previous studies as `inactive' turbulence. However, they are, in fact, dynamically highly active, supplying the major mechanism for the momentum transport, including upward bursting on the time scale of the larger eddies. The vertical velocity results show that the variance and the low frequency parts of spectra increase with height in the surface layer, while in the self similar (k₁ ^-1) range the streamwise low frequency components are approximately constant with height. These large-scale longitudinal eddies extend to a length _s, which is equal to the boundary-layer height near the surface andincreases linearly to a maximum of about three times the boundary-layer height at roughly 15 m and decreases in the upper parts of the surface layer. This lower part of the surface layer, the eddy surface layer, is the region in which the eddies impinging from layers above are strongly distorted. This new result for the atmospheric boundary layer has practical application for calculating fluctuating wind loads on structures and lateral dispersion of pollution from local sources.     

广西汛期旱涝与前期强信号的关系的统计分析

对影响广西汛期旱涝的一些主要物理因素,如海温、东亚季风、青藏高原积雪、印缅槽等做了一些初步的综合统计分析,了解这些物理因素与广西汛期旱涝的基本关系和事实.     

Present And Past Ice-Sheet Mass Balance Simulations For Greenland And The Tibetan Plateau

Net annual mass balance was evaluated for Greenland and the Tibetan Plateau using the meteorological forcings from the NCEP reanalysis and two GCMs (FOAM1.0 and CSM1.4) for modern climate and for different time periods extending back to the beginning of the Holocene (11,000 years ago) for the climate models. The ice-sheet budget calculations, using the degree day methodology, were performed on a finer grid than the model output by interpolating monthly precipitation and surface temperature and correcting the latter to account for the GCMs smoothed topography. The computed net mass balance for Greenland in the present day is positive and it ranges between 290–300 mm water equivalent (w.e.)/year for the two models, values close to the NCEP estimate of 250 mm/year. The past climate simulations show that the Greenland mass balance has become slightly more positive since the beginning of the Holocene. The Tibetan Plateaus present-day area average net mass balance is negative and ranges between –1200 and –2000 mm w.e. /year for the two models, values bracketing the NCEP estimate of 1700 mm/year, although the balance is positive over small regions of the plateau consistent with the existence of small ice caps and glaciers. The calculated past mass balance shows an increasingly less negative value for FOAM from 11,000 years ago towards the present and expansion of the positive mass balance areas, mainly due to decreased snow ablation as the summertime insolation decreases with the changes in orbital forcing; in CSM the opposite trend occurs but changes are smaller and less systematic. The result from FOAM shows that the likelihood of ice sheets developing on the Tibetan Plateau may have increased since 11000 years ago, which is consistent with some glacial records.     

Observations And Modelling Of The On-Ice And Off-Ice Air Flow Over The Northern Baltic Sea

Two cases of on-ice and off-ice air flow characterizing the opposite weather situations over the ice-edge zone in the northern Baltic Sea are analysed on the basis of aircraft observations, and modelled using atwo-dimensional mesoscale model. The stable boundary layer (SBL) during theon-ice flow exhibited little thermal modification, but a low-level jet (LLJ) was generated at the 250-m high top of the SBL. In the model, the LLJ was associated with inertial oscillations in space, while the baroclinicity explained the shape of the wind profile well above the SBL. Although the observed LLJ was most pronounced over the ice, the modelling suggests that it was not generated by the ice edge but by the coastline some 400 km upwind of the ice edge, where a much more drastic change in the thermal stratification and surface roughness took place. The generation, maintenance, and strength of the LLJ were very sensitive to the parameterization of turbulent mixing in the SBL. In the case of the off-ice flow, the modification of the air mass and the development of a convective boundary layer (CBL) both over the ice and open sea were reasonably well modelled. Sensitivity runs suggested that it was essential to take into account the effects of subgrid-scale leads, a forest in the archipelago (which was crossed by the air flow), and water vapour condensationinto ice crystals. The heat flux from leads was particularly important for the heatbudget of the CBL, and the observed growth of the CBL was partly due to theeffective mixing over the rough and relatively warm forest.     

人工观测与闪电定位探测雷暴日资料的对比分析

在对比分析人工观测雷暴日资料与闪电定位探测雷暴日资料的基础上,揭示了造成2种资料不一致的原因,并提出了应用闪电定位探测雷暴日资料时应注意的问题。研究结果认为,随着器测资料的积累。可提供1个客观的雷暴日分布场,从而改变人们对雷电分布的固有看法,以消除人工观测资料受多种因素影响而不够客观的局限。