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Interannual Meridional Displacement of the East Asian Upper-tropospheric Jet Stream in Summer

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Advances in atmospheric sciences 2005年第2期22卷 199-211页

作者：林中达陆日宇 institute of atmospheric physics chinese academy of sciences Beijing 100080 Graduate School of the Chinese Academy of SciencesBeijing 100039 institute of atmospheric physics chinese academy of sciences Beijing 100080

On the interannual timescale, the meridional displacement of the East Asian upper-tropospheric jet stream (EAJS) is significantly associated with the rainfall anomalies in East Asia in summer. In this study, using the data from the National Centers for Environmental Prediction-Department of Energy (NCEP/DOE) reanalysis-2 from 1979 to 2002, the authors investigate the interannual variations of the EAJS's meridional displacement in summer and their associations with the variations of the South Asian high (SAH) and the western North Pacific subtropical high (WNPSH), which are dominant circulation features in the upper and lower troposhere, respectively. The result from an EOF analysis shows that the meridional displacement is the most remarkable feature of the interannual variations of the EAJS in each month of summer and in summer as a whole. A composite analysis indicates that the summer (June-July-August, JJA) EAJS index, which is intended to depict the interannual meridional displacement of the EAJS, is not appropriate because the anomalies of the zonal wind at 200 hPa (U200) in July and August only, rather than in June, significantly contribute to the summer EAJS index. Thus, the index for each month in summer is defined according to the location of the EAJS core in each month. Composite analyses based on the monthly indexes show that corresponding to the monthly equatorward displacement of the EAJS, the South Asian high (SAH) extends southeastward clearly in July and August, and the western North Pacific subtropical high (WNPSH) withdraws southward in June and August.

关键词： East Asian jet stream western North Pacific subtropical high South Asian high interannual variations meridional displacement

Simulated Spatial Distribution and Seasonal Variation of atmospheric Methane over China:Contributions from Key Sources

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Advances in atmospheric sciences 2014年第2期31卷 283-292页

作者： ZHANG Dingyuan LIAO Hong WANG Yuesi State Key Laboratory of atmospheric Boundary Layer physics and atmospheric Chemistry institute of atmospheric physics Chinese Academy of Sciences University of chinese academy of sciences

We used the global atmospheric chemical transport model,GEOS-Chem,to simulate the spatial distribution and seasonal variation of surface-layer methane （CH4） in 2004,and quantify the impacts of individual domestic sources and foreign transport on CH4 concentrations over *** surface-layer CH4 concentrations over China exhibit maximum concentrations in summer and minimum concentrations in *** annual mean CH4 concentrations range from 1800 ppb over western China to 2300 ppb over the more populated eastern *** emissions were found to have large impacts on CH4 concentrations over China,contributing to about 85％ of the CH4 concentrations over western China and about 80％ of those over eastern *** tagged simulation results showed that coal mining,livestock,and waste are the dominant domestic contributors to CH4 concentrations over China,accounting for 36％,18％,and 16％,respectively,of the annual and national mean increase in CH4 concentration from all domestic *** from rice cultivation were found to make the largest contributions to CH4 concentrations over China in the summer,which is the key factor that leads to the maximum seasonal mean CH4 concentrations in summer.

关键词： methane GEOS-Chem seasonal variation foreign and domestic contributions

Synergistic Effects of Nitrogen Amendments and Ethylene on atmospheric Methane Uptake under a Temperate Old-growth Forest

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Advances in atmospheric sciences 2011年第4期28卷 843-854页

作者：徐星凯韩琳罗献宝韩士杰 State Key Laboratory of atmospheric Boundary Layer physics and atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of Sciences Graduate University of chinese academy of sciences institute of Applied Ecology Chinese Academy of Sciences

An increase in atmospheric nitrogen （N） deposition can promote soil acidification, which may increase the release of ethylene （C2H4） under forest floors. Unfortunately, knowledge of whether increasing N deposition and C2H4 releases have synergistic effects on soil methane （CH4） uptake is limited and certainly deserves to be examined. We conducted some field measurements and laboratory experiments to examine this issue. The addition of （NH4）2SO4 or NH4Cl at a rate of 45 kg N ha-1 yr-1 reduced the soil CH4 uptake under a temperate old-growth forest in northeast China, and there were synergistic effects of N amendments in the presence of C2H4 concentrations equal to atmospheric CH4 concentration on the soil CH4 uptake, particularly in the NH4Cl-treated plots. Effective concentrations of added C2H4 on the soil CH4 uptake were smaller in NH＋4 -treated plots than in KNO3-treated plots. The concentration of ca 0.3 μl C2H4 L-1 in the headspace gases reduced by 20% soil atmospheric CH4 uptake in the NH4Cl-treated plots, and this concentration was easily produced in temperate forest topsoils under short-term anoxic conditions. Together with short-term stimulating effects of N amendments and soil acidification on C2H4 production from forest soils, our observations suggest that knowledge of synergistic effects of NH＋4 , rather than NO3- , amendments and C2H4 on the in situ soil CH4 uptake is critical for understanding the role of atmospheric N deposition and cycling of C2H4 under forest floors in reducing global atmospheric CH4 uptake by forests. Synergistic functions of NH4＋ -N deposition and C2H4 release due to soil acidification in reducing atmospheric CH4 uptake by forests are discussed.

关键词： methane uptake ethylene nitrogen amendment synergistic effect forest

A New Precipitation Index for the Spatiotemporal Distribution of Drought and Flooding in the Reaches of the Yangtze and Huaihe Rivers and Related Characteristics of atmospheric Circulation

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Advances in atmospheric sciences 2011年第2期28卷 375-386页

作者：宗海锋张庆云 institute of atmospheric physics Chinese Academy of Sciences State Key Laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences

Characteristics of the spatiotemporal distributions of precipitation anomalies in the reaches of the Yangtze River and Huaihe River （YHR） were studied using EOF method. Four main precipitation pat-terns for the YHR in summer identified by the first two modes： a region-wide flood over the entire YHR （RWF）; a region-wide drought over the entire YHR （RWD）; a flood in the south with a drought in the northern region of the Yangtze River （FS-DN）; and a drought in the south with a flood in the northern region of the Yangtze River （DS-FN）. Based on the first two modes and the actual precipitation departure percentage, a new precipitation index is defined in this paper. The typical flood/drought years associated with the various rainfall patterns defined by this precipitation index are more representative and closer to reality compared to some existing precipitation indexes which just use the area-mean precipitation or the EOF time components individually. The characteristics of atmospheric circulation in summer corresponding to the four main precipitation patterns over the YHR in summer show the features of atmospheric circulation differ in different precipitation pattern years. Although the different patterns share a common main influential circulation system, such as the blocking high over northeastern Asia, the low trough of westerly flows in the mid latitudes, the West Pacific Subtropical High （WPSH）, and the high ridge over the Tibet Plateau, the difference in location and intensity of these systems can lead to different distributions of precipitation anomalies.

关键词： reaches of Yangtze River and Huaihe River precipitation index precipitation patterns

Modeling study on seasonal variation in aerosol extinction properties over China

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Journal of Environmental sciences 2014年第1期26卷 97-109页

作者： Yi Gao Meigen Zhang State Key Laboratory of atmospheric Boundary Layer physics and atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences

To investigate the seasonal variation of aerosol optical depth （AOD）, extinction coefficient （EXT）, single scattering albedo （SSA） and the decomposed impacts from sulfate （SO42-） and black carbon （BC） over China, numerical experiments are conducted from November 2007 to December 2008 by using WRF-Chem. Comparison of model results with measurements shows that model can reproduce the spatial distribution and seasonal variation of AOD and SSA. Over south China, AOD is largest in spring （0.6-1.2） and lowest in summer （0.2-0.6）. Over north, northeast and east China, AOD is highest in summer while lowest in winter. The high value of EXT under 850 hPa which is the reflection of low visibility ranges from 0.4-0.8 km-1 and the high value area shifts to north during winter, spring and summer, then back to south in autumn. SSA is 0.92-0.94 in winter and 0.94-0.96 for the other three seasons because of highest BC concentration in winter over south China. Over east China, SSA is highest （0.92-0.96） in summer, and 0.88-0.92 during winter, spring and autumn as the concentration of scattering aerosol is highest while BC concentration is lowest in summer over this region. Over north China, SSA is highest （0.9-0.94） in summer and lowest （0.82-0.86） in winter due to the significant variation of aerosol concentration. The SOn2- induced EXT increases about 5%- 55% and the impacts of BC on EXT is much smaller （2%-10%）. The SO42--induced increase in SSA is 0.01-0.08 and the BC-induced SSA decreases 0.02-0.18.

关键词： seasonal variation AOD EXT SSA China WRF-Chem

Vector meson's spin alignments in high energy reactions

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Science China(physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 5-20页

作者： Jin-Hui Chen Zuo-Tang Liang Yu-Gang Ma Xin-Li Sheng Qun Wang Key Laboratory of Nuclear physics and Ion-beam Application (MoE) Institute of Modern PhysicsFudan University institute of Frontier and Interdisciplinary Science Key Laboratory of Particle Physics and Particle Irradiation (MOE)Shandong University INFN-Firenze Department of Modern physics University of Science and Technology of China School of Mechanics and physics Anhui University of Science and Technology

The global spin alignment of vector mesons has been observed by the STAR collaboration at the Relativistic Heavy Ion Collider （RHIC） at Brookhaven National Laboratory （BNL）.It provides a unique opportunity to probe the correlation between the polarized quark and antiquark in the strongly coupled quark-gluon plasma （sQGP） produced in relativistic heavy ion collisions,opening a new window to explore the properties of s *** addition,spin alignments of vector mesons have also been observed in other high-energy particle collisions such as e+e-annihilations at high energies where hadron production is dominated by quark fragmentation *** results obtained are quite different from those obtained in heavy ion collisions where quark coalescence/combination mechanism dominates suggesting strong dependence on hadronization *** comprehensive studies in different hadronization processes are *** this article,we present a brief review of theoretical and experimental advances in the study of vector meson’s spin alignments in a variety of high-energy particle collisions,with emphasis on hadronization mechanisms.

关键词： vector meson spin alignment global polarization relativistic heavy ion collisions fragmentation

The 1997/ 98 ENSO Cycle and Its Impact on Summer Climate Anomalies in East Asia

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Advances in atmospheric sciences 2000年第3期17卷 348-362页

作者：黄荣辉张人禾张庆云 institute of atmospheric physics Chinese Academy of Sciences Beijing

The observed data of the sea surface temperature (SST) anomalies and the sea temperature (ST) in the sub-layer of the equatorial Pacific, the NCEP/ NCAR reanalysis data and the data set of daily precipitation in China are used to analyze the characteristics of the 1997 / 98 ENSO cycle and its impact on summer climate anomalies in East Asia. The results show that the 1997/98 ENSO cycle, the strongest one in the 20th century, might be characterized by rapid development and decay and eastward propagation from the West Pacific warm pool. Influenced by the ENSO cycle, in 1997, the serious drought and hot summer occurred in North China, and in the summer of 1998, the severe floods occurred in the Yangtze River valley, especially in the Dongting Lake and Boyang Lake valleys, South Korea and Japan. The analysis also shows that: influenced by the 1997/98 ENSO cycle, the water vapor transportation by the Asian monsoon in the summer of 1997 was very different from that in the summer of 1998. In the summer of 1997, the water vapor transportation by the Asian summer monsoon was weak in North China and the northern part of the Korea Peninsula. Thus, it caused the drought and hot summer in North China. However, in the summer of 1998, the sea temperature in the sub-layer of the West Pacific warm pool dropped, the western Pacific subtropical high shifted southward. Thus, a large amount of water vapor was transported from the Bay of Bengal, the South China Sea and the tropical western Pacific into the Yangtze River valley of China, South Korea and Japan, and the severe flood occurred there. Key words ENSO cycle - Climate anomaly - Monsoon - Drought and flood This study was supported by the National Key Programme for Developing Basic sciences under Grant No. G1998040900(I).

关键词： ENSO cycle Climate anomaly Monsoon Drought and flood

A Comparison Study of Tropical Pacific Ocean State Estimation:Low-Resolution Assimilation ***-Resolution Simulation

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Advances in atmospheric sciences 2005年第2期22卷 212-219页

作者：符伟伟朱江周广庆王会军 institute of atmospheric physics chinese academy of sciences Beijing 100029 Graduate School of the Chinese Academy of Sciences Beijing 100039 institute of atmospheric physics chinese academy of sciences Beijing 100029

A comparison study is performed to contrast the improvements in the tropical Pacific oceanic state of a low-resolution model respectively via data assimilation and by an increase in horizontal resolution. A low resolution model (LR) (1°lat by 2°lon) and a high-resolution model (HR) (0.5°lat by 0.5°lon) are employed for the comparison. The authors perform 20-yr numerical experiments and analyze the annual mean fields of temperature and salinity. The results indicate that the low-resolution model with data assimilation behaves better than the high-resolution model in the estimation of ocean large-scale features. From 1990 to 2000, the average of HR's RMSE (root-mean-square error) relative to independent Tropical Atmosphere Ocean project (TAO) mooring data at randomly selected points is 0.97℃ compared to a RMSE of 0.56℃ for LR with temperature assimilation. Moreover, the LR with data assimilation is more frugal in computation. Although there is room to improve the high-resolution model, the low-resolution model with data assimilation may be an advisable choice in achieving a more realistic large-scale state of the ocean at the limited level of information provided by the current observational system.

关键词： comparison study high-resolution model data assimilation low-resolution model

Synergistic impacts of anthropogenic and biogenic emissions on summer surface O_3 in East Asia

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Journal of Environmental sciences 2013年第3期25卷 520-530页

作者： Yu Qu Junling An Jian Li State Key Laboratory of atmospheric Boundary Layer physics and atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of Sciences

A factor separation technique and an improved regional air quality model （RAQM） were applied to calculate synergistic contributions of anthropogenic volatile organic compounds （AVOCs）,biogenic volatile organic compounds （BVOCs） and nitrogen oxides （NOx） to daily maximum surface O3（O3DM） concentrations in East Asia in summer （June to August 2000）.The summer averaged synergistic impacts of AVOCs and NOx are dominant in most areas of North China,with a maximum of 60 ppbv,while those of BVOCs and NOx are notable only in some limited areas with high BVOC emissions in South China,with a maximum of 25 *** result implies that BVOCs contribute much less to summer averaged O3DM concentrations than AVOCs in most areas of East Asia at a coarse spatial resolution （1×1） although global emissions of BVOCs are much greater than those of *** maximum total contributions of BVOCs can approach 20 ppbv in North China,but they can reach 40 ppbv in South China,approaching or exceeding those in some developed countries in Europe and North *** emissions in such special areas should be considered when O3 control measures are *** contributions among AVOCs,BVOCs and NOx significantly enhance O3 concentrations in the Beijing-Tianjin-Tangshan region and decrease them in some areas in South ***,the total contributions of BVOCs to O3DM vary significantly from day to day and from location to *** result suggests that O3 control measures obtained from episodic studies could be limited for long-term applications.

关键词： regional air quality model volatile organic compounds O3 factor separation technique synergistic contribution