我国和东亚地区硫化物跨边界输送态势研究

本文利用污染物三维欧拉长距离输送实用模式,较详细地模拟了我国和东亚地区硫化物跨地区、跨边界输送态势,分析了东亚地区硫化物输送通量随高度、季节变化的分布特点,讨论了不同地区边界上硫化物的跨边界输送通量及流的收支平衡,并给出了我国和周边国家和地区之间硫化物的相互输送量。结果表明,我国向外输送的硫化物占周边国家和地区总硫沉降的比例并不大,各地区硫沉降的主要来源是自身排放;硫化物长距离输送中硫酸根的输送占重要地位,各地区硫酸根沉降中的外来比例较大。我们初步总结出一个东亚地区硫化物输送的概念模式：在低层,夏季主要自西南向东北输送,冬季长江以北自北向南输送,长江以南由西南向北输送,并在长江中下游地区形成一个较强的硫化物辐合带,在高层,无论冬夏均由西向东输送,并随高空带变化,中层为二者的过渡,春秋季的情形界于冬夏之间,偏向冬季。     

非静力模式中几种垂直网格计算特性的对比研究

从非静力滞弹性方程组出发，将惯性重力波的水平波长分几百公里、几十公里和几公里三种情况，从频率、群速和各速的垂直尺度范围等方面对现有的几种垂直网格进行比较讨论。结果表明：在非静力模式中，CP网格和LZ网格适合于各种不同水平尺度惯性重力波的模拟；L网格和LY网格适合于水平尺度为几十公里以上的惯性重力波的模拟；LTS网格和CPTS网格比较适合于水平尺度的几十公里以下的惯性重力波的模拟。     

一次高空急流增强过程中的中尺度扰动和动量输送特征

本文利用中尺度数值模式的高分辨率模拟结果,研究了夏季东亚副热带西风急流一次短时间尺度强度变化过程中的中尺度西风扰动特征和相应的动量输送特征。结果表明,此次急流强度短时间尺度变化以急流轴线为界,北侧增强,南侧减弱。急流整体增强和急流内部中尺度西风扰动的积累效应有关。急流入口区(出口区)南侧主要为西风动量水平通量辐散区(辐合区),北侧为辐合区(辐散区),西风动量水平辐合辐散区的水平尺度只有百公里左右,也属于中尺度范围,并且辐合辐散区一般位于地形坡度较大区域上空。西风动量的垂直输送与西风动量水平通量散度分布几乎一致,但数值小一个量级以上。     

强雷暴环境的中尺度模拟

1.引言本文评述了当前有限区域中尺度模式提供中纬度强雷暴环境的准确预报以及风暴对环境可能的反馈作用的能力.这里的"中尺度模式"指的是用水平格距Δx=10～100公里作为在静力学原始方程中的有限差分近似.对平流波来说,要有满意的截断误差至少需4—6个格点(Pielke,1981),而要准确地计算非线性波的相互作用,则需近10个格点(Gerrity,1972).因此,这些模式适合模拟的天气现象尺度为Orlanski(1975)定义的中β尺度(25—250公里)上部到中α尺度     

嵌套网格空气质量预报模式系统的发展与应用

主要综述中国科学院大气物理研究所自主开发的嵌套网格空气质量预报模式系统(NAQPMS,Nested Air Quality Prediction Modeling System)的历史发展与应用情况.模式发展伊始为欧拉污染物输送实用模型,利用其研究东亚硫氧化物的跨国输送问题,得出中国对于周边国家的输送量不大的结论; 在系统中嵌入适合东亚的起沙机制模块,用来模拟沙尘发生、输送及沉降等过程,估算亚洲大陆沙尘气溶胶对海洋地区的输送与沉降通量,为研究海洋生物地球化学循环提供基础数据; 利用该系统研究沙尘及其土壤粒子对酸雨的中和作用,发现沙尘输送对东亚酸雨的分布影响很大; 发展城市尺度高分辨率气象和空气质量预报技术,使模式水平分辨率达到500 m,并应用于台北高浓度臭氧和PM10的模拟; 研究和集成区域及城市尺度大气污染预报理论和模拟技术,研制成目前的嵌套网格空气质量预报模式系统,以探讨不同尺度各种污染(如沙尘暴、城市光化学烟雾、酸雨、高浓度悬浮颗粒物等)的变化规律.在模式系统中初步建立资料同化模块,开展大气化学成分及沙尘输送模拟的资料同化研究.系统已经在北京、上海、深圳、郑州等城市环境监测中心实施空气质量的实时预报.未来,系统将集成到全球环境大气输送模式(GEATM),以实现从城市群到全球具有双向耦合功能的模式系统.     

大气环境数值模拟研究新进展

近五年来,中国科学院大气物理研究所(简称大气所)在大气环境数值模拟方面取得了丰硕的成果,通过自主发展和引进,建立了完备的多尺度、多成分的大气环境数值模式,包括全球大气化学输送模式、区域和城市空气质量预报模式。大气所利用这些模式研究各种空间尺度上污染物浓度时空分布以及污染物的输送和演变,研究了多种污染过程的成因和污染变化规律,在污染物输送、低对流层臭氧高污染、区域及城市污染等方面取得了很多成果,并对区域或城市空气质量进行业务化实时预报。大气所还拓展了我国大气环境模拟研究的新领域:大气化学资料同化、污染模式集合预报、污染源反演新方法。初步建立了空气质量模式的资料同化系统(分别基于最优插值技术和集合卡曼滤波技术)和多模式集合预报体系,提高了模式预报水平;在污染源反演新方法方面进行了初步的探索。结合我国目前仍然面临着的大气环境问题,对今后大气环境数值模式的发展方向进行了展望。     

基于强度尺度法的雷达和数值模式定量降水预报检验对比

为提高雷达外推和数值模式对短临预报能力的认识,采用强度尺度方法对比检验了2012年浙江省梅汛期内的雷达外推和WRF、T639、ECMWF 4类定量降水预报(QPF)产品。检验结果表明:短临预报的大部分误差来自较小的时空尺度,在强降水方面表现尤为明显。对于雷达和模式的预报能力交叉点(3 h前后)的QPF检验,雷达的误差比率随着空间尺度增大先减后增,而模式随尺度增大误差比率总体递减。在中小尺度(2 °及以下)雷达总体较准确,但0.25 °尺度是个特例,在较大尺度(4 °及以上)的弱降水上雷达不如模式。雷达在0.5 °、1 °尺度上相对误差贡献最少;在2 °、4 °尺度下,ECMWF表现最优。同时,雷达对于中-β和较小的中-α尺度系统的预报检验效果最好,对尺度达几百公里的弱系统不如数值模式,对于10~30 km的中-γ尺度系统雷达预报带来近74%的空报,今后需提高其对中-γ尺度系统生消的预报能力。      

区域化学输送模式中NO x和O3源示踪法的引入

发展了化学输送模式中氮氧化合物(NOx)和臭氧(O3)的一种源示踪方法,对这种示踪法及其应用模式作了详细介绍,并结合臭氧光化学反应机理的分析描述了NOx和O3示踪物浓度方程的推导过程。将这种示踪法引用到区域化学输送模式中,并以太原和石家庄地表NOx人为排放产生的活性氮化物和臭氧为例,演示了污染物向北京的输送过程,模拟的O3,NOx和NOz示踪物浓度时空分布与O3,NOx和NOz在大气中的衰减尺度分析一致,表明该示踪法是一种有效的研究区域氮氧化物以及臭氧来源和输送转化过程的方法。个例模拟分析结果显示:太原和石家庄的地表人为排放产生的NOx本身并不能输送到北京,但通过它们产生的O3和HNO3可以输送到北京,对北京地表附近大气污染造成影响。     

黑龙江省一次飑线过程中尺度和雷达分析

正1引言飑线是由多个雷暴单体,可能包含超级单体,侧向排列而形成的线状对流系统,其水平尺度长一般由几十到几百公里、宽度最宽几十公里,持续时间较短,飑线的发生发展机制及其带来的天气特征一直是强对流天气预报研究的重要问题~([1]),关于飑线的触发机制和中尺度结构已有学者做了大量的研究。Fujita~([2-4])根据地面气压场和降水的演变,给出了飑线     

暴雨中尺度模式的发展历程和研究进展

短期数值天气预报模式的发展,由于具备了对动力辐合、湿物理及边界层等过程和实际地形的刻画能力,在分辨率提高到几十公里尺度时,可以对暴雨进行数值预报。经过近50 a的发展,暴雨中尺度模式经历了静力平衡到非静力平衡、粗分辨率到高分辨率、简单物理过程到细致物理过程、云雨隐式预报到显式预报、简单初始化到复杂同化等的转变。本文从暴雨中尺度模式框架、物理过程和初始化方法三个方面,回顾了国内外主要暴雨中尺度模式的发展历程和重要进展,同时指出了未来模式可能的发展趋势并给予了分析讨论。     

Numerical Simulation of Regional Climate Change under IPCC A2 Scenario in China

Regional climate change in China under the IPCC A2 Scenario, was simulated for continuous 10-yr period by the MM5V3, using the output of an IPCC A2 run from CISRO Mark 3 climate system model as lateral and surface boundary conditions. The regional climate change of surface air temperature, precipitation, and circulation were analyzed. The results showed that （1） the distribution of mean circulation, surface air temperature, and precipitation was reproduced by the MM5V3. The regional climate model was capable to improve the regional climate simulation driven by GCM. （2） The climate change simulation under the IPCC A2 Scenario indicated that the surface air temperature in China would increase in the future, with a stronger trend in winter and the increasing magnitude from the south to the north. The precipitation distribution would appear a distinct change as well. Annual mean precipitation would remarkably increase in Northeast China, Yangtze and Huaihe River Valley, and the south area of the valley. Meanwhile, rainfall would show a decreasing trend in partial areas of North China, and many regions of Southwest and Northwest China.     

Predicting Patterns of Near-Surface Air Temperature Using Empirical Data

The signal of recent global warming has been detected in meteorological records, borehole temperatures and by several indirect climate indicators. Anthropogenic warming continues to evolve, and various methods are used to study and predict the changes of the global and regional climate. Results derived from GCMs, palaeoclimate reconstructions, and regional climate models differ in detail. An empirical model could be used to predict the spatial pattern of the near-surface air temperature and to narrow the range of regional uncertainties. The idea behind this approach is to study the correlations between regional and global temperature using century-scale meteorological records, and to evaluate the regional pattern of the future climate using regression analysis and the global-mean air temperature as a predictor. This empirical model, however, is only applicable to those parts of the world where regional near-surface air temperature reacts linearly to changes of the global thermal regime. This method and data from a set of approximately 2000 weather stations with continuous century-scale records of the monthly air temperature was applied to develop the empirical map of the regional climate sensitivity. Data analysis indicated that an empirical model could be applied to several large regions of the World, where correlations between local and global air temperature are statistically significant. These regions are the western United States, southern Canada, Alaska, Siberia, south-eastern Asia, southern Africa and Australia, where the correlation coefficient is typically above 0.9. The map of regional climate sensitivity has been constructed using calculated coefficients of linear regression between the global-mean and regional annual air temperature. As long as the correlations between the local and global air temperature are close to those in the last several decades, this map provides an effective tool to scale down the projection of the global air temperature to regional level. According to the results of this study, maximum warming at the beginning of the 21st century will take place in the continental parts of North America and Eurasia. The empirical regional climate sensitivity defined here as the response of the mean-annual regional temperature to 1 °C global warming was found to be 5–6 °C in southern Alaska, central Canada, and over the continental Siberia, 3–4 °C on the North Slope of Alaska and western coast of the U.S.A., and 1–2 °C in most of the central and eastern U.S.A. and eastern Canada. Regions with negative sensitivity are located in the southeastern U.S.A., north-western Europe and Scandinavia. The local tendency towards cooling, although statistically confirmed by modern data, could, however, change in the near future.     

南海海域海-气耦合模式及其数值模拟试验

在ＮＣＡＲ区域气候模式ＲｅｇＧＭ２和普林斯顿海洋模式ＰＯＭ基础上发展适用于区域海－气相互作用研究的区域海－气耦合模式,模式采用同步耦合、海洋模式将海表温度提供给大气模式,大气模式为海洋模式提供太阳短波辐射、感热能量、潜热通量。海洋与大气模式每１５ｍｉｎ交换一次通量。耦合过程没有使用通量校正。使用该模式对中国南海区域１９９５年５－７月大气和海洋进行了模拟试验,将模拟结果与ＣＯＡＤＳ通量强迫的模拟结果     

山区复杂地形上区域大气质量模式的试验研究

由于复杂地形上的气流多变，所以，进行区域空气质量模拟是比较困难的。根据大气污染总量控制和环境规划的需要，发展了一种可适用于山谷城市的大气质量模式，该模式的主要特点；（１）采用目前尚少的复杂地形上的三维边界层模式作为大气扩散模式所需城三维边界层要素场；（２）用复杂地形上的三维以模式和斯扩散氏架源（包括面源）和主架源所造在的地面ＳＯ２浓度，然后将两者的模拟浓度在相应网各上叠加。验证结果表明，该混合模式     

区域大气污染物浓度分布预报的一种模式及其试验

本文就区域尺度大气污染物浓度预报，提出一种以天气气候学分型为基础，结合大气污染物输放散区域污染物浓度区域分布逐日预报模式；并用该模式作预报试验，结果表明：模式的预报结果能达到一定的正确率，具有实用价值。     

Regional climate change experiments over southern South America. I: present climate

We present an analysis of a regional simulation of present-day climate (1981–1990) over southern South America. The regional model MM5 was nested within time-slice global atmospheric model experiments conducted by the HadAM3H model. We evaluate the capability of the model in simulating the observed climate with emphasis on low-level circulation patterns and surface variables, such as precipitation and surface air mean, maximum and minimum temperatures. The regional model performance was evaluated in terms of seasonal means, seasonal cycles, interannual variability and extreme events. Overall, the regional model is able to capture the main features of the observed mean surface climate over South America, its seasonal evolution and the regional detail due to topographic forcing. The observed regional patterns of surface air temperatures (mean, maxima and minima) are well reproduced. Biases are mostly within 3°C, temperature being overestimated over central Argentina and underestimated in mountainous regions during all seasons. Biases in northeastern Argentina and southeastern Brazil are positive during austral spring season and negative in other seasons. In general, maximum temperatures are better represented than minimum temperatures. Warm bias is larger during austral summer for maximum temperature and during austral winter for minimum temperature, mainly over central Argentina. The broad spatial pattern of precipitation and its seasonal evolution are well captured; however, the regional model overestimates the precipitation over the Andes region in all seasons and in southern Brazil during summer. Precipitation amounts are underestimated over the La Plata basin from fall to spring. Extremes of precipitation are better reproduced by the regional model compared with the driving model. Interannual variability is well reproduced too, but strongly regulated by boundary conditions, particularly during summer months. Overall, taking into account the quality of the simulation, we can conclude that the regional model is capable in reproducing the main regional patterns and seasonal cycle of surface variables. The present reference simulation constitutes the basis to examine the climate change simulations resulting from the A2 and B2 forcing scenarios which are being reported in a separate study.     

一种基于全球动力模式和SMART原理结合的统计降尺度区域季节气候预测方法

针对江苏夏季旱涝和高温热浪等异常气候的预测难题，以江苏夏季站点降水和气温为预测目标，建立了一种基于全球动力模式BCC_CSM1.1（m）和最优可预测气候模态和异常相对倾向（SMART）原理结合的统计降尺度季节气候预测方法。利用历史观测资料和SVD方法提取决定中国夏季降水异常相对倾向的同期热带地区向外长波辐射（Outgoing Longwave Radiation，OLR）和北半球中高纬500 hPa位势高度场异常相对倾向的最优可预测气候模态，并利用逐步回归法构建其与同期江苏站点降水和气温异常相对倾向同期关系的统计降尺度模型；将动力模式对最优可预测气候模态的预测带入统计降尺度模型，实现对区域降水和气温异常相对倾向的预测；最后通过引入观测的近期背景异常实现对降尺度的降水和气温总距平的预测。通过对1991—2019年江苏夏季降水和气温的回报检验表明，本文建立的统计降尺度模型效果较BCC_CSM1.1（m）动力模式的直接预测效果有显著提高，为区域精细化季节气候预测提供了一种有效的手段。     

区域气候模式RegCM_NCC在东北地区的应用研究

引进国家气候中心业务化的区域气候模式RegCM_NCC,通过操作系统调试、模拟区域确定、模式分辨率调整等本地化工作,初步建立了针对东北地区的区域气候模式系统,并应用该模式以夏季为例,对东北地区的气候进行了15 a（1991—2005年）时间长度的数值积分试验。结果表明：模式对环流的特征和东北地区地面气温具有一定的模拟能力,对气温模拟存在系统性的暖偏差,对降水模拟能力较差。