Wave-CISK、蒸发-风反馈和低频振荡

本文利用一个包含有Wave-CISK和蒸发-风反馈机制的斜压半地转模式来讨论低纬大气运动,其中引入了反映CISK机制的无量纲对流凝结加热参数η和反映蒸发-风反馈机制的无量纲参数α_0,求得了η=0情况下的解析解及η≠0情况下的一级近似解,对η≠0情况下向东传播的类似于低频振荡的波动进行了讨论,从理论上指出了蒸发及非均匀加热对低频振荡的维持所起的重要作用.     

Wave-CISK的一个斜压半地转模式和低频振荡

本文建立了一个描写低纬大气运动的斜压半地转的wave-CISK模式,其中引入了一个反映CISK机制的无量纲的凝结潜热参数η(z),并求得了η=0和η≠0条件下wave-CISK模式的解析解,理论研究进一步说明wave-CISK机制对于大气低频振荡起重要的作用。     

CISK、蒸发-风反馈机制和热带大气30-60天振荡

建立一个包含ＣＩＳＫ机制和蒸发－风反馈机制（Ｅｖａｐｏｒａｔｉｏｎ－ＷｉｎｄＦｅｅｄｂａｃｋＭｅｃｈａｎｉｓｍ，简写为：ＥＷＦＭ）的热带大气运动的无耗散、线性斜压半地转模式，引入反映ＣＩＳＫ的无量纲凝结潜热参数η和反映ＥＷＦＭ的无量纲参数α，并求得模式系统的解析解。动力学分析和模式大气的计算结果进一步说明了ＣＩＳＫ和ＥＷＦＭ的共同作用是激发和驱动热带大气低频振荡的重要物理过程。     

青藏高原感热加热对7月份大气环流和亚洲夏季风影响的数值试验

根据低纬地区地表温度高、蒸发及降水量大、辐合上升运动剧烈等特点,本文构造了一个正压模式的方程组,提示出影响低纬大气波动的一个重要因素——海表温度SST。研究指出:(1)当SST<25℃时,含蒸发风反馈机制的Rossby波向西传播,当SST>25℃时.含蒸发风反馈机制的Rossby波向东传播。(2)SST的数值越高,空气越潮湿,含蒸发风反馈机制的Rossby波传播速度就越小。当SST超过29℃时,会形成周期为30天的低频振荡。     

蒸发－风反馈机制的进一步研究

对蒸发-风反馈的作用进行了简单动力学研究。结果表明,蒸发-风反馈不能像波动-CISK那样改变热带大气波动的性质(减缓移速),不可能单独成为激发热带大气季节内振荡的动力学机制。在积云对流加热和蒸发-风反馈的共同作用下,CISK-Kelvin波和CISK-Rossby波可以不稳定发展,共同作用比单独的积云对流加热反馈作用能更全面合理地解释热带大气季节内振荡的活动。因此,蒸发-风反馈对于热带大气季节内振荡也有重要作用。      

Wave-CISK和低纬大气低频振荡

本文运用一个包含Wave-CISK机制的斜压半地转模式来讨论低纬大气中的低频振荡。在我们以前研究工作的基础上，不仅考虑了CISK机制的作用，而且考虑了CISK机制垂直速度w[B]随纬度的变化。这样，建立的半地转模式和相应的解析解更能反映CISK机制对低纬低频振荡的作用。在求解中，我们运用了本征函数S[-3/2][m]（Sonine多项式）展开的方法，结果不仅得到了模式中所含的CISK-Kelvin波和CISK-Rossby波波速与对流凝结潜热参数η的关系，而且显示了低纬高、低层大气间的相互耦合作用。在这样     

蒸发—风反馈机制的进一步研究

对蒸发－风反馈的作用进行了简单动力学研究。结果表明，蒸发－风反馈不能像波动－ＣＩＳＫ那样改变热带大气波动的性质，不可能单独成为激发热带大气内振荡的动力学机制。在积云对流加热的蒸发－风反馈的共同作用下，ＣＩＳＫ－Ｋｅｌｖｉｎ波和ＣＩＳＫ－Ｒｏｓｓｂｙ波可以不稳定发展，共同作用比单独和积云对流加热反馈作用能更全面合理地解释热带大气内振荡的活动。     

正压模式中的非绝热波动

应用含有非绝热因子的正压模式方程组,着重分析了对流凝结加热、蒸发－风反馈和ＣＩＳＫ机制等非绝热因子对低纬Ｒｏｓｓｂｙ波和Ｋｅｌｖｉｎ波的影响。既获得了圆频率的表达式,又分析了波的周期与稳定性。结果表明：非绝热因子的存在不但扩大了绝热波的周期,而且改变了波的稳定性。因此,可以认为：所谓季节内振荡（３０—６０天的周期振荡）等低频振荡实际上是一类非绝热波,这类非绝热波是引起中长期天气变化及短期气候演变的重要因素。     

青藏高原西部地表热通量输送的低频特征

以1997年9月-1998年10月青藏高原西部改则地区自动气象站(AWS)近地层连续观测的梯度资料为基础,计算了高原西部地面感热通量、蒸发潜热通量及地面热源强度,应用Marr小波变换重点分析了地表热通量输送以及与此相关的降水量、土壤湿度和土壤热通量的周期振荡特征.结果表明:地面感热具有明显的30～60天低频振荡,并且在夏季存在准8天的中期振荡;蒸发潜热和降水量以准双周振荡为主.土壤热通量以30～50天低频振荡为主,夏季还存在准8天的中期振荡;土壤湿度在冬季呈现明显的30～50天低频振荡,夏季则为20～30天的低频振荡.     

大气低频振荡的数值模拟

本文利用IAP_GCM积分结果中10年候平均资料，研究了模式大气中的低频振荡现象。结果表明，该模式能相当逼真地模拟出低频振荡的地理分布、垂直结构和传播过程的主要特征，因而低频振荡是大气本身所固有的一种现象。而流场与大气加热场之间在低频域内的相关分析则证实了大气加热对低频振荡的产生起重要的作用，其中最重要的因子是水汽潜热的释放。     

COMPARATIVE ANALYSIS OF VARIOUS DATA OF AIR–SEA TEMPERATURE DIFFERENCE AND ITS VARIATION ACROSS SOUTH CHINA SEA IN THE PAST 35 YEARS

Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.     

Could the Recent Taal Volcano Eruption Trigger an El Ni?o and Lead to Eurasian Warming?

正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment.     

VARIABILITY OF INTER-ANNUAL RELATIONSHIP BETWEEN INDIAN OCEAN DIPOLE AND HUAXI REGION’S AUTUMN PRECIPITATION

The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.     

IMPACT OF ATMOSPHERIC LOW-FREQUENCY OSCILLATION ON THE IMMIGRATION OF NILAPARVATA LUGENS(STL) IN HUNAN AND JIANGXI PROVINCES

Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.     

A COMPARATIVE ANALYSIS OF ATMOSPHERIC AND OCEANIC CONDITIONS BEFORE THE OCCURRENCE OF TWO TYPES OF EL NIO EVENTS

The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o.     

全球贸易隐含碳变化及其影响分析

基于最新的GTAP8 (Global Trade Analysis Project）数据库,使用投入产出法,分析了2004年到2007年全球贸易变化下南北集团贸易隐含碳变化及对全球碳排放的影响。结果显示,随着发展中国家进出口规模扩张,全球贸易隐含碳流向的重心逐渐向发展中国家转移。2004年到2007年,发达国家高端设备制造业和服务业出口以及发展中国家资源、能源密集型行业及中低端制造业出口的趋势加强,该过程的生产转移导致全球碳排放增长4.15亿t,占研究时段全球贸易隐含碳增量的63%。未来发展中国家的出口隐含碳比重还将进一步提高。贸易变化带来的南北集团隐含碳流动变化对全球应对气候变化行动的影响日益突出,发达国家对此负有重要责任。     

Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings

正ERRATUM to: Atmospheric and Oceanic Science Letters, 4(2011), 124-130 On page 126 of the printed edition (Issue 2, Volume 4), Fig. 2 was a wrong figure because the contact author made mistake giving the wrong one. The corrected edition has been updated on our website. The editorial office is sincerely sorry for any     

Index to Vol.31

正AN Junling;see LI Ying et al.;(5),1221—1232AN Junling;see QU Yu et al.;(4),787-800AN Junling;see WANG Feng et al.;(6),1331-1342Ania POLOMSKA-HARLICK;see Jieshun ZHU et al.;(4),743-754Baek-Min KIM;see Seong-Joong KIM et al.;(4),863-878BAI Tao;see LI Gang et al.;(1),66-84BAO Qing;see YANG Jing et al.;(5),1147—1156BEI Naifang;     

Information for Contributors

正Journal of Meteorological Research is an international academic journal in atmospheric sciences edited and published by Acta Meteorologica Sinica Press,sponsored by the Chinese Meteorological Society.It has been acting as a bridge of academic exchange between Chinese and foreign meteorologists and aiming at introduction of the current advancements in atmospheric sciences in China.The journal columns include Articles.Note and Correspondence,and research letters.Contributions from all over the world are welcome.