应用ATOVS资料和非对称Bogus资料对登陆台风韦帕的4DVAR数值模拟分析

前人研究中BDA方法采用的轴对称Bogus台风不能反映个别台风具体特征并弃掉了背景场的合理成分,也没有考虑大环境场的影响及湿热要素的同化。因此,提出一种充分融合分析场信息和实际观测信息并考虑副高影响的精细非对称台风Bogus方法,并在MM5的伴随同化系统中引入快速辐射传输模式RTTOV8,通过四维变分同化(4DVAR)技术,加入海面风场和气压场Bogus资料及多颗卫星多条轨道上的ATOVS红外和微波卫星辐射亮温资料并考虑Noah陆面过程方案来对登陆台风韦帕进行数值模拟,结果表明,单独同化海面Bogus资料的BDA方案可间接产生初始场非对称三维环流结构和暖心结构,但对湿度场及台风周围大环境场的调整不足,台风登陆后的路径预报改善也不明显;引入陆面过程方案弥补了Bogus资料对台风登陆后路径预报的不足;加入ATOVS资料能对湿度场及台风周围环境场做出调整,重构了大量中尺度结构信息,取得更为精细的初始台风环流和温压湿场结构,保持BDA方案路径及强度预报的优势的同时,使预报的降水强度增加,降水落区发生改变。     

The Structure and Rainfall Features of Tropical Cyclone Rammasun （2002）

Tropical Rainfall Measuring Mission (TRMM) data [TRMM Microwave Imager/Precipitation Radar/Visible and Infrared Scanner (TMI/PR/VIRS)] and a numerical model are used to investigate the structure and rainfall features of Tropical Cyclone (TC) Rammasun (2002). Based on the analysisof TRMM data, which are diagnosed together with NCEP/AVN [Aviation (global model)] analysis data,some typical features of TC structure and rainfall are preliminary discovered. Since the limitations of TRMM data are considered for their time resolution and coverage, the world observed by TRMM at several moments cannot be taken as the representation of the whole period of the TC lifecycle, therefore the picture should be reproduced by a numerical model of high quality. To better understand the structure and rainfall features of TC Rammasun, a numerical simulation is carried out with mesoscale model MM5 in which the validations have been made with the data of TRMM and NCEP/AVN analysis.     

消去分析台风方法的对比研究

详细分析了GFDL飓风模式和MM5模式消去分析台风的原理, 通过10个台风个例的对比分析指出, GFDL方案从平均意义上求取分析台风中心位置和半径的方法, 优于MM5方案采用涡度极值来确定分析台风中心以及将分析台风中心半径定为常数的方法。而MM5方案考虑要素场之间的协调, 较GFDL方案更为合理。试验结果表明:通过将两者优点相结合对MM5方案进行修正, 能够更加合理、彻底地消去分析台风。     

WRF模式不同云参数化方案的暴雨预报能力检验及集成试验

利用WRFV3. 6的8种微物理方案和6种积云参数化方案对湖北及其周边地区夏季12次暴雨过程进行回报,分析各种方案对暴雨预报的影响。结果显示,各种方案均能较好地预报出降水过程,但其降水强度和范围存在一定差异。当积云参数化方案为KF方案时,对Lin、WSM6、Thompson、Morrison 2-mom、CAM5. 1、WDM5、WDM6、NSSL 2-mom微物理方案做敏感性试验,发现CAM 5. 1方案优于其他7种微物理方案,M orrison 2-mom次之。当微物理方案为CAM 5. 1时,对KF、BM J、GD、SAS、G3D、Tiedtke积云参数化方案做敏感性试验,发现在不同量级降水预报中,6种积云参数化方案各有优劣。综合考虑,GD、SAS、Tiedtke积云参数化方案优于其他3种方案。在此基础上开展多方案集成试验,结果表明集合平均(ensemble mean,EMN)在一定程度上可以减少预报误差,降低单个成员预报的不确定性。     

The Korean emissions trading scheme: business perspectives on the early years of operations

Korea’s domestic emissions trading scheme commenced in January 2015. It targeted mainly industrial and power sectors, and compelled companies to transform how they manage energy efficiency and mitigate GHGs. This study sets out to explore how Korean companies evaluated their allocation position and engaged in emissions trading in the first compliance period, and to identify their views on trading barriers and policy expectations at the start of emissions trading. Questionnaire surveys and on-site interviews targeting Korean companies under the Korean emissions trading scheme were conducted at the start of operations (February to March 2015) and after the first compliance year (May 2016), respectively. Actual operation results are observed and compared with the survey findings. This study extrapolates implications for policy and presents suggestions for the government and the target companies in terms of how to improve the current emissions trading scheme in order to further stimulate emissions trading.

POLICY RELEVANCE

This study attempts to bridge the gap between companies and government policy in operating the domestic emission trading scheme in Korea. Empirical results, based on analysis of company-level data, reveal how businesses perceive K-ETS and how this relates to the operating results, which saw only limited trading of surplus emissions taking place in the early phase. Key barriers to active trading identified in the study include supply–demand imbalance, policy uncertainty and lack of preparedness of companies over carbon pricing. These barriers could be addressed by improved transparency of allowance allocation methods, possibly restricting carry-over of surplus allowances, ending policy uncertainty and providing more information to companies that can support companies’ policy understanding of the carbon pricing based on the market mechanism. Targeted companies should proactively participate in emissions trading in the early phase, in order to learn from it and prepare for the future introduction of auctioning.     

河南省春季一次层状云降水云系结构和降水机制的数值模拟

利用PSU/NCAR的MM5中的双参数显式云物理方案,模拟了2007年河南省春季一次层状云降水过程,模拟结果显示,降雨主要落区和强度与观测一致.24 h降雨预报的TS评分较高.模式输出的雷达反射率与郑州站雷达RHI回波相比较,模拟的回波结构基本符合层状云回波特征,存在零度层亮带.在成功降水模拟的基础上,分析了云系不同部位结构特征和粒子质量通量分布,发现雨水的形成在不同部位依靠不同的过程.郑州站云的垂直结构和降水微物理过程研究表明,降水机制符合"播种一供给"机制,降水形成主要依靠雪的融化和暖云微物理过程,暖云对整层降水起主要作用,暖云微物理过程是形成降水的更有效方式.     

修正的质量通量积云对流方案及其模拟试验研究 Ⅱ:三种积云方案的积云对流活动及MFS方案相关参数的敏感性试验

作者在“修正的质量通量积云对流方案及其模拟试验研究I方案介绍及对1991年洪涝过程的模拟”论文中提出的质量通量方案成功地植入区域气候模式RegCM2的基础上，对比分析质量通量方案MFS，Kuo方案和Grell方案对积云对流活动的模拟，结果表明质量通量方案较好地模拟了积云对流活动过程。针对质量通量方案中的一些参数，如云水向雨水的转换率、混合卷入率、混合卷出率和下沉气流的强度等进行了一系列的敏感性试验，试验结果表明积云对流活动对这些参数比较敏感，因此提高这些参数的准确性是改进积云对流参数化方案的重要内容之一。     

IAP AGCM4.0模式对热带大气季节内振荡的模拟评估

基于中国科学院大气物理所大气环流模式IAP AGCM4.0总共30年(1979~2008年)的模拟结果,评估了IAP AGCM4.0模式对热带大气季节内振荡的模拟能力。分析结果表明IAP AGCM4.0模式可以在一定程度上模拟出热带大气季节内振荡的主要时空谱结构特征,在周期30~80天处存在明显的谱能量中心;模式模拟的季节内振荡东传的主要特征与观测基本一致,东移波的能量远大于西移波。基于RMM指数(All-season Real-time Multivariate MJO Index)的分析表明,模式模拟的850 h Pa和200 h Pa季节内尺度风场和对流活动在赤道地区的空间分布与观测基本一致。但与观测相比,模式模拟的热带大气季节内振荡的周期较短,东传速度快于观测,虚假的西传特征过强,对流活跃区域范围较小、强度较弱。就非绝热加热而言,模式模拟结果与再分析资料比较接近,但最大加热在印度洋和西太平洋地区出现的位相较晚。进一步分析表明,模式中影响对流触发的相对湿度阈值(RHc)的不同取值(RHc分别取为85%、90%、95%和100%),可以显著影响热带大气非绝热加热垂直廓线,从而影响模式对热带大气季节内振荡的模拟;当对流触发相对湿度阈值取为90%时,IAP AGCM4.0模式对热带大气季节内振荡模拟的能力相对最好,非绝热加热垂直廓线在不同位相的分布特征也与再分析资料最为接近。这说明模式对流参数化方案中不同参数的合适选取,可以改进模式对热带大气季节内振荡的模拟能力。     

Prediction of sea fog of Guangdong coastland using the variable factors output by GRAPES model

By analyzing the NCEP 1°×1° reanalysis (2004–2008), a number of predictors (factors of variables) are established with the output from the GRAPES model and with reference to the sea fog data from observational stations (2004–2008) and field observations (2006–2008). Based on the criteria and conditions for sea fog appearance at the stations of Zhanjiang, Zhuhai and Shantou, a Model Output Statistics (MOS) scheme for distinguishing and forecasting 24-h sea fog is established and put into use for three repres...     

两种不同积云参数化方案对1998年中国夏季洪涝灾害数值模拟的比较研究

利用国家气候中心的全球T63谱模式，以1998年夏季(6-8月)我国长江中下游和东北嫩江—松花江流域发生的特大洪水为试验个例，分别采取原来模式中的Kuo积云参数比方案和UKMO/unifled的Gregory积云参数比方案进行了整个夏季的逐月降水预报的对比试验。结果表明：Gregory质量通量方案能给出较Kuo方案更加合理的降水落区，并且对降水量的预报也有显著的改进。此外，Gregory质量通量方案对大尺度环流背景场的预报也较Kuo方案好。从整个夏季的预报来看，Gregory参数化方案能较Kuo方案更好地模拟出1998年的降水的总体趋势，尽管Gregory方案模拟的降水与实况相比，仍然存在着系统性的误差，还需要进一步改进。