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Some characteristics of the atmosphere during an adiabatic process

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Progress in Natural Science:Materials International 2006年第6期16卷 644-648页

作者： GAO Li, LI Jianping and ren hongli (LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 100029, china Graduate School of Chinese Academy of Sciences, beijing 100049, china national climate center, laboratory of climate studies, china meteorological administration, beijing 100081, china) LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate School of Chinese Academy of Sciences Beijing 100049 China national climate center Laboratory of Climate Studies China Meteorological Administration Beijing 100081 China

Some important characteristics of the atmosphere during an adiabatic process are investigated, which include the invariability of atmospheric entropy range and local surface potential temperature, the conservation of the atmospheric mass intervened between any isentropic surface and the ground, and the isentropic surface intersecting with the ground. The analysis shows that the atmospheric reference state (ARS) for investigation on available potential energy (APE) should be defined objectively as the state which could be approached from the existing atmosphere by adiabatic adjustment, and be related to initial atmospheric state before adjustment. For the initial atmosphere state at any time, its corresponding ARS is different from the one at another time. Based on the above-mentioned conclusions, the reference state proposed by Lorenz cannot be obtained physically, so a new conception, the conditional minimum total potential energy, is put forward in order to objectively investigate atmospheric APE.

关键词： available potential energy adiabatic isentropic surface atmospheric reference state conditional minimum total potential energy.

Strategy and methodology of dynamical analogue prediction

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Science china Earth Sciences 2007年第10期50卷 1589-1599页

作者： ren hongli1,2? & CHOU JiFan1 1 College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, china 2 laboratory for climate studies, national climate center, china meteorological administration, beijing 100081, china College of Atmospheric Sciences Lanzhou University Lanzhou 730000 China laboratory for climate studies National Climate Center China Meteorological Administration Beijing 100081 China College of Atmospheric Sciences Lanzhou University Lanzhou 730000 China

In order to effectively improve numerical prediction level by using current models and data, the strategy and methodology of dynamical analogue prediction (DAP) is deeply studied in the present paper. A new idea to predict the prediction errors of dynamical model on the basis of historical analogue information is put forward so as to transform the dynamical prediction problem into the estimation problem of prediction errors. In terms of such an idea, a new prediction method of final analogue correction of errors (FACE) is developed. Furthermore, the FACE is applied to extra-seasonal prediction experiments on an operational atmosphere-ocean coupled general circulation model. Prediction results of summer mean circulation and total precipitation show that the FACE can to some extent reduce prediction errors, recover prediction variances, and improve prediction skills. Besides, sensitive experiments also show that predictions based on the FACE are evidently influenced by the number of analogues, analogue-selected variables and analogy metric.

关键词： dynamical analogue prediction, prediction strategy, analogue correction of errors, extra-seasonal prediction

Change in Extreme Temperature Event Frequency over china's mainland during 1961-2008

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Change in Extreme Temperature Event Frequency over China's m...

Causes, Processes and Consequences of Sandstorms in Northern china : A case study of sandstorms in 2000

强化科技基础推进气象现代化——第29届中国气象学会年会

作者： Yaqing Zhou 1,2 Guoyu ren 2,1 Jinzhong meteorological Bureau of Shanxi Province,Jinzhong 030600,china 2 laboratory for climate studies,national climate center,china meteorological administration(CMA),beijing 100081,china

利用 526 个国家级气象站 1961～2008 年的日最高、最低气温资料,分析了中国大陆地区气温极端事件的变化规律。结果表明,中国大陆地区霜冻日数和结冰日数明显减少,结冰日数减少显著的区域集中在北方,霜冻日数则在整个中国区域都显著减少... 详细信息

利用 526 个国家级气象站 1961～2008 年的日最高、最低气温资料,分析了中国大陆地区气温极端事件的变化规律。结果表明,中国大陆地区霜冻日数和结冰日数明显减少,结冰日数减少显著的区域集中在北方,霜冻日数则在整个中国区域都显著减少,夏季日数和炎热夜数明显增多,增多显著的区域主要在长江中下游和西南地区南部。日最高(低)气温的极大(小)值整体都有上升趋势,最高(低)气温的极大值在北方上升较明显,而在长江中下游和西南地区有下降的趋势;最高(低)气温的极小值则在全国范围都呈明显上升,极端最低气温上升尤为显著。冷夜 (昼)日数普遍明显减少,48 年中减少趋势为 8.23 d.(10 yr)-1[3.26 d.(10 yr)-1];暖夜(昼)日数明显增加,增加趋势为 8.16 d.(10 yr)-1[5.22 d.(10 yr)-1]。冷夜(昼)日数减少主要发生在冬季,其次是春、秋季,而暖昼和暖夜日数增加最显著的季节分别出现在秋季和夏季。从转折时间上看,极端气温指数的冷指是从 20 世纪 80 年代中后期开始显著减少的,暖指显著增加的时间则推迟到 20 世纪 90 年代中期。华北区域的研究结果表明,对于和最低气温有关的极端指数而言,城市化有显著影响,它加剧了冷指数的减少和暖指数的增加,国家站极端指数趋势变化中有 4 成以上是城市化造成的。另外城市化对气温日较差的影响也十分显著,近 48 年中国家站气温日较差的趋势变化基本上都是由城市化造成的。城市化对极端气温指数的影响不容忽视。

关键词：极端气温指数最高气温最低气温气候变化中国大陆

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Chinese Forestry Science and Technology 2003年第4期2卷 5-17页

作者： LU Qi YANG Youlin WANG Sen WU Bo ren Guoyu JU Hongbonational Research and Development center for Combating DesertificationChinese Academy of Forestry. beijing 100091. chinaAsia Regional Coordinating Unit. Secretariat of the UNCCD. Bangkok 10200. Thailand Pacific Forestry center. Canadian Forest Service. Natural Resources Canada506 West Burnside Road. Victoria. BC. Canada V8Z 1M5 national climate center of china meteorological administration. Beiiine 100081. china

Serious land degradation exists in the marginal areas of North china, the important ecological transition between semi-arid and sub-humid climate zones, which is a relatively narrow belt with 100-250 km in width and about 2 000 km in length. The annual rainfall varies between 300-400 mm. In the past hundred years (before 2000), most of the land in the region had been used for grazing and dryland cropping. As land-use is intensifying, particularly since 1970s and 1980s, desertification has accelerated. O...

关键词： sandstorms climatic factors nationwide trend regional trend Northern china

Representation of the ENSO Combination Mode and its Asymmetric SST Response in Different Resolutions of HadGEM3

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Advances in Atmospheric Sciences 2018年第8期35卷 167-180页

作者： Jianghua WAN hongli ren Peili WU laboratory for climate studies and CMA-NJU Joint Laboratory for Climate Prediction Studies National Climate Center China Meteorological Administration Beijing 100081 China Department of Atmospheric Sciences School of Environment Studies University of Geoscience Wuhan 430074 China Met Office Hadley center Exeter EX1 3PB UK

Previous studies have revealed a combination mode （C-mode） occurring in the Indo-Pacific region, arising from nonlinear interactions between ENSO and the western Pacific warm pool annual cycle. This paper evaluates the simulation of this C-mode and its asymmetric SST response in HadGEM3 and its resolution sensitivity using three sets of simulations at horizontal resolutions of N96, N216 and N512. The results show that HadGEM3 can capture well the spatial pattern of the C-mode associated surface wind anomalies, as well as the asymmetric response of SST in the tropical Pacific, but it strongly overestimates the explained variability of the C-mode compared to the ENSO mode. The model with the three resolutions is able to reproduce the distinct spectral peaks of the C-mode at the near annual combination frequencies, but the performance in simulating the longer periods is not satisfactory, presumably due to the unrealistic simulation of the ENSO mode. Increasing the horizontal resolution can improve the consistency between atmospheric and oceanic representations of the C-mode, but not necessarily enhance the accuracy of C-mode simulation compared with observation.

关键词： ENSO combination mode asymmetric response Nifio-A index HadGEM3 horizontal resolution

The Boreal Summer Intraseasonal Oscillation Simulated by Four Chinese AGCMs Participating in the CMIP5 Project

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Advances in Atmospheric Sciences 2014年第5期31卷 1167-1180页

作者： ZHAO Chongbo ZHOU Tianjun SONG Lianchun ren hongli laboratory for climate studies National Climate Center China Meteorological Administration State Key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences national climate center China Meteorological Administration

The performances of four Chinese AGCMs participating in the Coupled Model Intercomparison Project Phase 5 （CMIP5） in the simulation of the boreal summer intraseasonal oscillation （BSISO） are assessed. The authors focus on the major characteristics of BSISO： the intensity, significant period, and propagation. The results show that the four AGCMs can reproduce boreal summer intraseasonal signals of precipitation; however their limitations are also evident. Compared with the climate Prediction center Merged Analysis of Precipitation （CMAP） data, the models underestimate the strength of the intraseasonal oscillation （ISO） over the eastern equatorial Indian Ocean （IO） during the boreal summer （May to October）, but overestimate the intraseasonal variability over the western Pacific （WP）. In the model results, the westward propagation dominates, whereas the eastward propagation dominates in the CMAP data. The northward propagation in these models is tilted southwest-northeast, which is also different from the CMAP result. Thus, there is not a northeast-southwest tilted rain belt revolution off the equator during the BSISO＇s eastward journey in the models. The biases of the BSISO are consistent with the summer mean state, especially the vertical shear. Analysis also shows that there is a positive feedback between the intraseasonal precipitation and the summer mean precipitation. The positive feedback processes may amplify the models＇ biases in the BSISO simulation.

关键词： boreal summer intraseasonal oscillation AGCM simulation feedback

Subtropical Air-Sea Interaction and Development of Central Pacific El Nio

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Journal of Ocean University of china 2013年第2期12卷 260-271页

作者： XIE Ruihuang HUANG Fei ren hongli Department of Marine Meteorology Physical Oceanography Laboratory and Key Laboratory of Ocean-Atmosphere Interaction and Climate in Universities of ShandongOcean University of China Department of Meteorology School of Ocean and Earth Science and TechnologyUniversity of Hawaii laboratory for climate studies National Climate CenterChina Meteorological Administration

The standard deviation of the central Pacific sea surface temperature anomaly （SSTA） during the period from October to February shows that the central Pacific SSTA variation is primarily due to the occurrence of the Central Pacific E1 Nifio （CP-E1 Nifio） and has a connection with the subtropical air-sea interaction in the northeastern Pacific. After removing the influence of the Eastern Pacific E1 Nifio, an S-EOF analysis is conducted and the leading mode shows a clear seasonal SSTA evolving from the subtropical northeastern Pacific to the tropical central Pacific with a quasi-biennial period. The initial subtropical SSTA is generated by the wind speed decrease and surface heat flux increase due to a north Pacific anomalous cyclone. Such subtropical SSTA can further influence the establishment of the SSTA in the tropical central Pacific via the wind-evaporation-SST （WES） feedback. After established, the central equatorial Pacific SSTA can be strengthened by the zonal advective feedback and thermocline feedback, and develop into CP-E1 Nifio. However, as the thermocline feedback increases the SSTA cooling after the mature phase, the heat flux loss and the reversed zonal advective feedback can cause the phase transition of CP-EI Nifio. Along with the wind stress variability, the recharge （discharge） process occurs in the central （eastern） equatorial Pacific and such a process causes the phase consistency between the thermocline depth and SST anomalies, which presents a contrast to the original recharge/discharge theory.

关键词： CP-E1 Nifio subtropical forcing recharge/discharge process phase consistency thermocline depth

Large-scale low-frequency rainfall regimes and their transition modes in summertime over china

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Chinese Science Bulletin 2006年第11期51卷 1355-1367页

作者： ren hongli ZHANG Peiqun CHOU Jifan LI Weijing GAO Li College of Atmospheric Sciences Lanzhou University Lanzhou 730000 China laboratory for climate studies National Climate Centre China Meteorological Administration Beijing 100081 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Seven large-scale low-frequency rainfall regimes (LFRRs) in summertime are identified for china in a 10-dimensional phase space by using a 40-year daily precipitation dataset. Corresponding to the local extrema of observed probability density in phase space, the LFRRs are characterized by the persistence and transitions that reflect the spread and jump features of low-frequency rainfall centers. The LFRRs are generally consistent with summer monsoon rainbelts on the intraseasonal timescale, and there exist the preferred transition relationships between the LFRRs. Four LFRRs’ transition modes (LFRRTMs), which are the dominant components of the interannual and intraseasonal variability of sum- mer rainfall in china, are further induced. Analyses of atmospheric circulation system show that the anomalies of the subtropical high over the western Pacific (SHWP) and blockings in mid-high latitudes, the low-latitude circulation anomalies, and the wavetrains over the East Asia-Pacific region (EAPWs), play crucial roles in the occurrence and transitions of the LFRRs. Moreover, the evolution of the SHWP and blockings, the distribution and movement of the EAPWs, and the intraseasonal variability of the East Asian-Pacific jet stream may be principal factors of the formations of the LFRRTMs.

关键词：夏季降雨相空间低频降雨体系大尺度预报

Progress in ENSO prediction and predictability study

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national Science Review 2018年第6期5卷 826-839页

作者： Youmin Tang Rong-Hua Zhang Ting Liu Wansuo Duan Dejian Yang Fei Zheng hongli ren Tao Lian Chuan Gao Dake Chen Mu Mu State Key laboratory of Satellite Ocean Environment Dynamics Second Institute of Oceanography Environmental Science and Engineering University of Northern British Columbia Prince George Key laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of Sciences Qingdao national laboratory for Marine Science and Technology State Key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences College of Oceanography Hohai University International center for climate and Environment Science Institute of Atmospheric PhysicsChinese Academy of Sciences laboratory for climate studies & CMA—NJU Joint laboratory for climate Prediction studies National Climate CenterChina Meteorological Administration College of Atmospheric and Oceanic Science Fudan University

ENSO is the strongest interannual signal in the global climate system with worldwide climatic, ecological and societal impacts. Over the past decades, the research about ENSO prediction and predictability has attracted broad attention. With the development of coupled models, the improvement in initialization schemes and the progress in theoretical studies, ENSO has become the most predictable climate mode at the time scales from months to seasons. This paper reviews in detail the progress in ENSO predictions and predictability studies achieved in recent years. An emphasis is placed on two fundamental issues: the improvement in practical prediction skills and progress in the theoretical study of the intrinsic predictability limit. The former includes progress in the couple models, data assimilations, ensemble predictions and so on, and the latter focuses on efforts in the study of the optimal error growth and in the estimate of the intrinsic predictability limit.

关键词： ENSO prediction and predictability coupled model ensemble prediction optimal error growth probabilistic prediction