CLIMATIC CHARACTERISTICS OF EARTH-ATMOSPHERE OUTGOING LONGWAVE RADIATION OVER CHINA*

ERBE and ISCCP data are used to investigate the cloud forcing and latitude and atmospheric temperature effects on outgoing longwave radiation(OLR) in the earth-atmosphere system,and the similarity of OLR field to 500 hPa and surface effective radiation fields.Also,discussion is taken up of the OLR distribution on a nationwide basis,indicating that the winter(summer) OLR pattern is roughly a zonal type(asymmetrical saddle) with the annual pattern analogous to the January one.In the end the yearly OLR variation features are addressed on a regional basis.     

CLIMATIC CHARACTERISTICS OF NET RADIATION IN THE EARTH-ATMOSPHERE SYSTEM OVER CHINA

Investigated are effects of the total cloudiness and other factors on earth-atmosphere net radia-tion(EANR)and analyzed is its relation to other components and ground surface net radiation inthe context of ERBE and ISCCP.Evidence suggests that planetary scale albedo and earth-atmo-sphere short wave absorption radiation have maximum effect on the net radiation under study,withthe influence of cloud and latitude displayed predominantly through the two factors;OLR has rela-tively weak effect;the earth-atmosphere net radiation is well correlated with surface net radiation.Analysis is also performed of the geographic distribution of the earth-atmosphere net radiationthroughout China,and the annual curve of the net radiation on a local basis is marked by high(low)value in summer(winter)with the impact of factors.including total cloudiness responsiblelargely for the shift of the months with maximum.     

CLIMATIC CHARACTERISTICS OF NET RADIATION IN THE EARTH-ATMOSPHERE SYSTEM OVER CHINA*

Investigated are effects of the total cloudiness and other factors on earth-atmosphere net radiation(EANR) and analyzed is its relation to other components and ground surface net radiation in the context of ERBE and ISCCP.Evidence suggests that planetary scale albedo and earth-atmosphere short wave absorption radiation have maximum effect on the net radiation under study,with the influence of cloud and latitude displayed predominantly through the two factors;OLR has relatively weak effect;the earth-atmosphere net radiation is well correlated with surface net radiation.Analysis is also performed of the geographic distribution of the earth-atmosphere net radiation throughout China,and the annual curve of the net radiation on a local basis is marked by high(low) value in summer(winter) with the impact of factors.including total cloudiness responsible largely for the shift of the months with maximum.     

中国地－气系统净辐射的气候特征

根据ＥＲＢＥ和ＩＳＣＣＰ资料讨论了总云量等因子对地－气系统净辐射的影响，分析了地－气系统净辐射与其各分量及地表净辐射的相关联系。发现行星反射率和地气短波吸收辐射对地－气净辐射的影响最大，而云和纬度的作用主要通过该两因子变化表现出来，ＯＬＲ的作用则相对较弱。地－气净辐射与地表净辐射的相关性也较明显。文中还就地－气净辐射在全国的地理分布作了分析。各地区地－气净辐射的年变曲线均为简单的夏大冬小型，云等因素的影响主要造成最大值出现月份的推移。     

ADVANCES IN APPLIED RESEARCH OF THE OUTGOING LONGWAVE RADIATION IN CHINA

The outgoing longwave radiation(OLR)observed by NOAA satellite series has widely applied in various researchfields since the 1980s in China.In this paper,advances of the applied research of OLR are described in the following re-spects:(1)Studies of the global ITCZ;(2)Climatology of the subtropical high over northern Pacific;(3)Studies of the tropical cyclone over West Pacific;(4)Characteristics of the intraseasonal variation(ISV)of tropical convective activities;(5)Divergence wind and large scale circulation over the tropics;(6)Studies of the air-sea interaction;(7)Estimation of precipitation over the Tibetan Plateau and the Yangtze River(Changjiang River)basin during therainy season;(8)Analyses of regional climates of China;(9)Studies of prediction of the severe and disastrous weather and climate;(10)Atlas of OLR.The distinctive features of these advances are reviewed and the focal points of the OLR applied research in futureare also suggested.     

CLIMATIC CHARACTERISTICS OF ATMOSPHERIC NET RADIATION OVER CHINA

In terms of ERBE and ISCCP data.and measured/calculated surface net radiation,computation is performed of the climatic characteristics of ANR(atmospheric net radiation)acrossChina alongside with the discussion and relations to other two kinds of radiation and contributingfactors.Evidence suggests a high linear correlation of ANR with atmosphere-absorbed shortwaveradiation.whereby can be established a general expression for ANR,which decreases more sharplyas a function of altitude and increases slightly with latitude in summer,and changes uniformly inwinter.Eventually,a comparison is made of the findings presented in this paper and literaturesregarding the ANR pattern and magnitudes,indicating their great difference.     

中国地区云对地气系统长波射出辐射（OLR）强迫的气候研究

本文利用地球辐射平衡试验（ERBE）和国际卫星去气候计划（ISCCP）提供的地气系统长波射出辐射（OLR）和云量资料，计算半讲座了我国各季和年平均去量对地气系统OLR的强迫及其所产生的温室效应，结果表明：我国各季的OLR云强迫与总云量，高云量都有较好的相关，且季节变化明显；OLR云强迫和云温室效应的地理分布受云量和云状的影响较大，它们的年变化一般呈弱双峰型，峰值在春，夏季出现。     

青藏高原云对地气系统长波射出辐射(OLR)强迫的气候研究

利用地球辐射平衡试验（ＥＲＢＥ）和国际卫星云气修计划（ＩＳＣＣＰ）提供的地气系统长波射出辐射（ＯＬＲ）和云量资料,计算并讨论了青藏高原地气系统各季和年平均总云量对ＯＬＲ的强迫及其所产生的温室效应,揭示了高、低示了高、低云对ＯＬＲ强迫的特点。结果表明：高原的ＯＬＲ云强迫与总云量、高云量都有较好的相关关系,且季节变化明显;ＯＬＲ云强迫和云温室效应的地理分布与高原总云量的分布较为一致;云强迫的年变化一同     

中国地—气系统长波射出辐射（OLR）的气候特征

根据ERBE和ISCCP资料讨论了云对地—气系统长波射出辐射（OLR）的强迫作用及纬度、大气温度等因子的影响。分析了OLR场与500hPa及地表有效辐射场的相似问题。阐述了OLR在全国的分布特征，指出冬季OLR场大致呈纬向型．夏季为一不对称的鞍形场。年分布与1月的相似。最后还就各区域的OLR年变化特征进行了讨论．     

CLIMATIC CHARACTERISTICS OF ATMOSPHERIC NET RADIATION OVER CHINA*

In terms of ERBE and ISCCP data.and measured/calculated surface net radiation,computation is performed of the climatic characteristics of ANR(atmospheric net radiation) across China alongside with the discussion and relations to other two kinds of radiation and contributing factors.Evidence suggests a high linear correlation of ANR with atmosphere-absorbed shortwave radiation.whereby can be established a general expression for ANR,which decreases more sharply as a function of altitude and increases slightly with latitude in summer,and changes uniformly in winter.Eventually,a comparison is made of the findings presented in this paper and literatures regarding the ANR pattern and magnitudes,indicating their great difference.     

向外长波辐射(OLR)与广东降水

利用OLR资料以及广东降水资料,分析了广东各季降水与OLR场的关系,探讨了热带低频振荡对广东后汛期降水的影响。主要结论是:来自北方的天气系统影响是广东前汛期降水的基本条件,而后汛期降水则以来自东南方向的热带系统为主。另外,就整个后汛期平均而言,西太平洋低频振荡中心位置偏北(南)时,该年后汛期降水偏多(少);若就短期气候而言,则低频振荡处于不同位相,相应副热带高压、ITCZ等也发生周期性的变化,从而影响广东降水的低频振荡,因此西太平洋低频振荡所处的位相对广东降水影响很大。     

INVESTIGATION OF LAGGED CORRELATION BETWEEN THE TEMPERATURE OF CHINA AND THE GLOBAL OUTGOING LONGWAVE RADIATION IN 1974-1985

1-12 month lagged correlations between winter temperatures at 22 stations in China and the global dis-tribution of the Outgoing Longwave Radiation(OLR)are investigated.The basic results are:(1)Themonthly averaged temperatures of Dec.,Jan.and Feb.of China are correlated to the global distribution ofOLR of Oct.,Nov.and Dec.,respectively.It is consistent with the response period(about 50 days)of 500hPa geopotential height field in extratropical latitudes to the thermal forcing in tropical latitudes,and also consis-tent with the Walker cell of a 40-60 day oscillation.(2)There is a significant positive correlation betweenthe winter temperature of the most part of China and the OLR in the Gulf of Mexico.It shows that whenthe thermal forcing of the Gulf of Mexico is stronger,the excited barotropic instability of westerlies in northernAtlantic could influence the East Asian circulation and cause the temperature of China to be below normal.(3)The temperature around the Tibetan(Xizang)Plateau is negatively correlated to the OLR in western equa-torial Pacific,showing that when the Walker cell is stronger,the local Hadley cell in Southeast Asia isstronger and it causes the temperature around the Tibetan Plateau to be higher than normal.     

中国大气净辐射的气候特征

根据ＥＲＢＥ和ＩＳＣＣＰ资料以及实测和计算和地表净辐射资料进行了计算，并讨论了我国大气净辐射的气候特征；分析了其与各辐射分量及影响因子的关系。结果表明，大气净辐射与大气吸收波辐射有很高的线性关系，并可由此建立起统一的大气净辐射计算式。     

青藏高原OLR场的气候特征

青藏高原OLR明显偏低。季节变化特点是1月到5月不断增值，3－5月增值迅速。5－8月高原北部继续增值，但南部云量增多，出现了低值区。低值区5月份在喜马拉雅山南侧，然后自东南向西北扩展，越过喜马拉雅山，7月低值轴线到达31°N附件；8月开始自西北向东南撒；9月退到喜马拉雅山南侧；10月开始下降，西北部下降迅速，东南部下降缓慢。年变化曲线特点是：高原北部为单峰型，最高值出现在8月；南部为双峰型，高值分别出现在5月和10月，低值出现在7月。     

青藏高原地区地-气系统的辐射平衡特征

本文利用1982年8月—1983年7月青藏高原热源野外考察期间的Nimbus7卫星观测资料,分析了高原及其邻近地区行星反照率、大气顶的射出长波辐射和地-气系统辐射平衡的区域分布及季节变化特征以及它们对天气气候的影响。同时配合同期的地面辐射观测资料,讨论了卫星资料与地面实测资料间的相互关系,为探索卫星资料的应用等作了尝试。     

中国大陆地区的OLR与厄尔尼诺现象

本文利用美国NOAA极轨卫星观测的1974年6月—1986年2月2.5×2.5经纬度网格区月平均的OLR资料,计算分析了中国大陆地区地—气系统射出长波辐射(OLR)的基本气候特征,给出了OLR的年、季平均值及均方差的空间分布图。并计算分析了1974—1985年期间厄尔尼诺年与反厄尔尼诺年中国大陆地区OLR的差异,进行对比分析,初步得到一些有意义的现象。     

热带OLR异常的遥相关结构及其季节变化

本文用单点相关研究了1月和7月热带OLR异常的遥相关结构及其季节变化。结果表明，热带纬带（15°N-15°S）遥相关型具有纬向偶极结构和准驻波性。1月遥相关具有热带波数2的结构，它反映了东非（赤道中太平洋）和南美（热带西太平洋）之间的非绝热加热异常存在翘翘板（Seesaw）关系；7月遥相关呈热带1波型，它同全球最强的行星尺度热源异常的东西振荡相联系。遥相关型对季节变化的敏感性主要表现为全球热带纬带几个热源（汇）区强度变化和纬向位移，以及东非的遥相关在6-9月符号变异，并由此引起遥相关型从冬到夏从波数2向波     

ANALYSIS OF THE CLIMATIC CHARACTERISTICS OF LANDING TROPICAL CYCLONES IN EAST CHINA

The intensity, landing time, track trend and intensity variation of tropical cyclones (TCs) after landfall are analyzed using the TCs data (of best track from the China Meteorological Administration) between 1949 and 2006 for the western North Pacific and South China Sea. The trend differences of track and intensity between the TCs that directly land in East China and those making the second landfall in East China after landing in Taiwan Island are categorically discussed. The results show that the first kind of landing TCs are more likely to go northward or turn while the second kind of TCs have a larger tendency to keep going northwest. The intensity of the first kind of TCs is more persistent than the second one. There is a higher percentage for the intensity to be weakened significantly if the TCs keep going west to northwest or southwest after landing.     

THE CLIMATIC CHARACTERISTICS OF SUMMER MONSOON ONSET OVER THE SOUTH CHINA SEA I.40-YEAR AVERAGE

By using 40-year NCEP reanalysis daily data (1958-1997), we have analyzed the climatic characteristics of summer monsoon onset in the South China Sea (105°E ~ 120°E, 5°N ~ 20°N, to be simplified as SCS in the text followed) pentad by pentad (5 days). According to our new definition, in the monsoon area of the SCS two of the following conditions should be satisfied: 1) At 850hPa, the southwest winds should be greater than 2m/s. 2) At 850 hPa, θ_se should be greater than 335°K. The new definition means that the summer monsoon is the southwest winds with high temperature and high moisture. The onset of the SCS summer monsoon is defined to start when one half of the SCS area (105°E ~ 120°E,5°N ~ 20°N) is controlled by the summer monsoon. The analyzed results revealed the following: 1) The summer monsoon in the SCS starts to build up abruptly in the 4th pentad in May. 2) The summer monsoon onset in the SCS is resulted from the development and intensification of southwesterly monsoon in the Bay of Bengal. 3) The onset of the summer monsoon and establishment of the summer monsoon rainfall season in the SCS occur simultaneously. 4) During the summer monsoon onset in the SCS, troughs deepen and widen quickly in the lower troposphere of the India; the subtropical high in the Western Pacific moves eastward off the SCS in the middle troposphere; the easterly advances northward over the SCS in the upper troposphere.     

长江流域旱涝的OLR特征

卫星观测的OLR(射出长波辐射)资料已在大气环流变化及气候异常的研究中得到广泛的应用。本文试图利用美国气候分析中心所提供的9年NOAA卫星所观测的OLR资料,对长江流域的夏季雨量的估算进行试验并对旱年、涝年的广大低纬地区的OLR特征进行诊断分析,为卫星资料应用于长江流域的旱涝分析预报作一初步探索。