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Comparison of Beijing MST Radar and Radiosonde Horizontal Wind Measurements

Advances in Atmospheric Sciences 2017年第1期34卷 39-53页

作者： Yufang TIAN daren lu Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

To determine the performance and data accuracy of the 50 MHz Beijing Mesosphere-Stratosphere-Troposphere （MST） radar, comparisons of radar measured horizontal winds in the height range 3-25 km with radiosonde observations were made during 2012. A total of 427 profiles and 15 210 data pairs were compared. There was very good agreement between the two types of measurement. Standard deviations of difference （mean difference） for wind direction, wind speed, zonal wind and meridional wind were 24.86° （0.77°）, 3.37 （-0.44）, 3.33 （-0.32） and 3.58 （-0.25） m s^-1, respectively. The annual standard deviations of differences for wind speed were within 2.5-3 m s^-1 at all heights apart from 10-15 km, the area of strong winds, where the values were 3-4 m s^-1. The relatively larger differences were mainly due to wind field variations in height regions with larger wind speeds, stronger wind shear and the quasi-zero wind layer. A lower MST radar SNR and a lower percentage of data pairs compared will also result in larger inconsistencies. Importantly, this study found that differences between the MST radar and radiosonde observations did not simply increase when balloon drift resulted in an increase in the real-time distance between the two instruments, but also depended on spatiotemporal structures and their respective positions in the contemporary synoptic systems. In this sense, the MST radar was shown to be a unique observation facility for atmospheric dynamics studies, as well as an operational meteorological observation system with a high temporal and vertical resolution.

关键词： MST radar radiosonde horizontal wind measurement comparison and analysis

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Global structures of the DE3 tide

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Chinese Science Bulletin 2009年第6期54卷 1073-1079页

作者： CHEN ZeYu lu daren LAGEO/Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The Hough mode decomposition (HMD) is used to investigate the global structures of the eastward propagating diurnal tide of zonal wavenumber 3 (DE3). The tide is delineated by using the SABER/ TIMED temperatures collected during 2002―2006. The HMD analysis results show that the DE3 tide is primarily dominated by two leading propagating Hough modes, i.e., (-3, 3) and (-3, 4) modes; the in-fluences .of the other Hough modes including trapped modes can be neglected. Based upon the HMD analysis results, this paper first reported the maximum of the tidal activity in the MLT region. The re-sults show that the DE3 tide exhibits annual unimodal distribution with the maximal amplitude occur-ring at 110 km in late summer (around July each year). Moreover, characteristic 2-year period variation is observed in the (-3, 3) Hough mode. And this type of inter-annual variation is further reflected in the tidal amplitude at 110 km height. For example, corresponding to the 2-year variation of the (-3, 3) mode, the DE3 tidal amplitude exhibits two substantially enhanced activities with maximal amplitude exceed-ing 12 K in 2002 and 2004, respectively. Moreover, current investigation results indicate that the influ-ence of the second propagating Hough mode, (-3, 4) mode, is important, in particular at the height un-der 100 km, where the DE3 amplitudes exhibit antisymmetric distribution with respect to the equator. The (-3, 4) mode exhibits bimodal distribution over a yearly course, which dominates the DE3 tide in the lower mesosphere. For example, two maximal DE3 activities were observed in late-winter-to-early- spring and late-autumn-to-early-winter, respectively. The first maximum is seen in the south of the equator, and the second maximum is in the north of it.

关键词：大蛋白潮流结构头盔显示器大振幅模式分解年际变化调查结果

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Statistics of gravity waves in the lower stratosphere over Beijing based on high vertical resolution radiosonde

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Science China Earth Sciences 2005年第9期48卷 1548-1558页

作者： BIAN Jianchun CHEN Hongbin lu daren Institute of Atmospheric Sciences Chinese Academy of Sciences Beijing 100029 China Institute of Atmospheric Sciences Chinese Academy of Sciences Beijing 100029 China Institute of Atmospheric Sciences Chinese Academy of Sciences Beijing 100029 China

The seasonal variation of inertia gravity-wave activity in the lower stratosphere (17―24 km) over Beijing is studied based on the high vertical resolution radionsonde observa- tions (from December 2001 to February 2003) of Beijing Observatory (116°28′E, 39°48′N). Some of the important gravity-wave parameters, such as intrinsic frequency, and propagation direction, are estimated according to the polarized relation among gravity-wave wind components and temperature. Time series of wave energy show that the largest wave amplitudes occur during the winter and the least during the summer, and the average of the KE:PE ratios is about 2.6. Zonal and meridional wind perturbations have almost the same roots of mean variances, which shows that the wave energy in the lower stratosphere is isotropic horizontally. The motion and tem- perature fields are dominated by waves with vertical wavelengths of 1.5―3 km, which occupy above 80% samples, with a mean value of about 2.3 km. The horizontal wavelengths are mainly distributed between 100―800 km, averaging 445 km. The ratio of the mean horizontal to vertical wavelength is about 200:1, which indicates that the wave propagates nearly horizontally, with a very small vertical angle. The intrinsic frequency is estimated by fitting a polarized ellipse to the wind perturbations after band-filtering waves with a wavelength of 1.5―3 km, and the results show that the intrinsic frequency is dominated by 1f―3.5f, with an averaging value of 2f, corre- sponding to an intrinsic time period of 9 hours. Wave energy is found to propagate mainly upward, and in the horizontal direction, there is clear azimuthal anisotropy, with predominate northwest propagation against the prevailing wind.

关键词： inertia gravity waves, lower stratosphere, polarized relation, intrinsic frequency, propagation direction.

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Atmospheric Profiling Synthetic Observation System in Tibet

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Advances in Atmospheric Sciences 2018年第3期35卷 264-267页

作者： daren lu Weilin PAN Yinan WANG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China

1. Introduction The Atmosphere Profiling Synthetic Observation System （APSOS） is the first ground-based facility for profiling atmospheric variables and multiple constituents in the whole （neutral） atmosphere from the surface up to the lower thermosphere. It enables simultaneous observations and extensive studies of the atmospheric vertical structure and constituent transport.

关键词： SO CAS Figure TP

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Impact of cloud inhomogeneity on bi-directional reflectance

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Chinese Science Bulletin 2008年第1期53卷 124-130页

作者： WANG Yue lu daren HUO Juan Laboratory for Middle Atmosphere and Global Environment Observation Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

This paper uses SHDOM (Spherical Harmonics Discrete Ordinate Method) to calculate the nadir bidi-rectional reflectance distribution function (BRDF) of the cumulus and stratocumulus fields at the wave-lengths of 0.67 μm and 2.13μm, and discusses the impact of cloud inhomogeneity on BRDF. The cloud fields are adopted from I3RC Phase II, which are used to compare 3D radiative transfer models. The simulation results show that the cu field has 6% abnormal BRDF values (BRDF>1) with the increase of solar zenith angle. Further analyses show that grid cells whose BRDF is greater than one gather to-gether at the local trough of the top of cloud. These regions can receive not only the direct incident solar beam, but also the beam scattered by the higher cloud of its neighborhood. Hence, the BRDF of those regions is enhanced. The abnormal BRDF phenomenon shows that the cloud inhomogeneity can result in inconsistency between satellite observation and plane parallel theory, implying that the re-flectance observed by high resolution satellite is maybe enhanced by the cloud 3D effects. Thus one should take this fact into account when using the product retrieved by these data. The dominant solar zenith angles are quite large in the mid-high altitude area, and the impact of cloud inhomogeneity on these areas may be more significant.

关键词：云层反射率方向分布函数

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Application of cloud multi-spectral radiances in revealing cloud physical structures

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Earth and Planetary Physics 2019年第2期3卷 126-135页

作者： Juan Huo daren lu WenJing Xu Key Laboratory for Atmosphere and Global Environment Observation Chinese Academy of Sciences

The radiances scattered or emitted by clouds demonstrate diverse features at different wavelengths due to different cloud physical structures. This paper presents a method(the smallest-radiance-distance method, SRaDM) of revealing the physical structures of clouds. The method is based on multi-spectral radiances measured by the Moderate Resolution Imaging Spectroradiometer(MODIS)onboard Aqua. The principle and methodology of SRaDM is deduced and provided in this paper. Correlation analysis based on data from MODIS and Cloud Profiling Radar(onboard CloudSat), collected from January 2007 to December 2010 over an ocean area(15°N–45°N,145°E–165°E), led to selection of radiances at 13 wavebands of MODIS that demonstrated high sensitivity to cloud physical structures;radiances at the selected wavebands were subjected to SRaDM. The Standardized Euclidean distance is introduced to quantify the degree of changes in multi-spectral radiances(termed D_(rd)) and in physical structures(termed D_(st)) between cloud profiles. Statistics based on numerous cloud profiles show that D_(rd) decreases monotonically with a decrease in D_(st), which implies that small D_(rd) always accompanies small D_(st). According to the law of D_(rd) and D_(st), the new method, SRaDM, for revealing physical structures of clouds from the collocation of cloud profiles of similar multi-spectral radiances, is presented. Then, two successful experiments are presented in which cloud physical structures are captured using multi-spectral radiances. SRaDM provides a way to obtain knowledge of the physical structures of clouds over relatively larger areas, and is a new approach to obtaining 3D cloud fields.

关键词： cloud physical structure radiance radar

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First Global Carbon Dioxide Maps Produced from Tan Sat Measurements

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Advances in Atmospheric Sciences 2018年第6期35卷 621-623页

作者： Dongxu YANG Yi LIU Zhaonan CAI Xi CHEN lu YAO daren lu Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China

*** need for global carbon monitoring from space and the TanSat mission Global warming is a major problem,for which carbon dioxide（CO2 ）is the main greenhouse gas involved in heating the ***,the poor availability of... 详细信息

关键词： OCO First Global Carbon Dioxide Maps Produced from Tan Sat Measurements

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ADVANCES ON STUDY OF MIDDLE AND UPPER ATMOSPHERE AND THEIR COUPLING WITH LOWER ATMOSPHERE

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空间科学学报 2002年第Z1期22卷 111-119页

作者： lu daren YI Fan XU Jiyao Institute of Atmospheric Physics The Chinese Academy of Sciences Beijing 100029 P.R. China College of Electronic Engineering Wuhan University P.R. China Center for Space Science and Application Research The Chinese Academy of Sciences P.R. China

In this paper advances on study of middle and upper atmosphere and their cou pling with lower atmosphere in China in recent two years are briefly *** review emphasized three aspects, ie. (1) analysis and observation of mid and upper atmosphere over China; (2) theoretical and modelling study of grav ity wave activities in middle atmosphere and their relation to lower atmospheric processes; (3) coupling between the stratosphere and troposphere.

关键词： Middle atmosphere, Gravity waves, Stratosphere-Troposphere Exchange(STE)

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Retrievals of over-ocean precipitable water from SSM/I by SOM network model

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Chinese Science Bulletin 1999年第11期44卷 1038-1041页

作者： Jianchun Bian Hongbin Chen Peicai Yang daren lu Peking Univ Dept Geophys Beijing 100871 Peoples R China Chinese Acad Sci Inst Atmospher Phys LAGEO Beijing 100029 Peoples R China

An SOM network model was developed for retrievals of the oceanic total precipitable water (PW) from the SSM/I, by using the SSM/I and radiosonde observation data set provided by the NASDA (Japan). The model was first trained by 5/6 of the data, and the other data were used to test the retrieval ability of the model. The retrieval results showed that the SOM network model was better than the routine operational algorithm.

关键词： SOM network SSM/I precipitable water.

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The Impact of Cut-off Lows on Ozone in the Upper Troposphere and Lower Stratosphere over Changchun from Ozonesonde Observations

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Advances in Atmospheric Sciences 2016年第2期33卷 135-150页

作者： Yushan SONG daren lu Qian LI Jianchun BIAN Xue WU Dan LI Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 University of Chinese Academy of Sciences Beijing 100049

In situ measurements of the vertical structure of ozone were made in Changchun （43.53°N, 125.13°E）, China, by the Institute of Atmosphere Physics, in the summers of 2010-13. Analysis of the 89 validated ozone profiles shows the vari- ation of ozone concentration in the upper troposphere and lower stratosphere （UTLS） caused by cut-off lows （COLs） over Changchun. During the COL events, an increase of the ozone concentration and a lower height of the tropopause are observed. Backward simulations with a trajectory model show that the ozone-rich airmass brought by the COL is from Siberia. A case study proves that stratosphere-troposphere exchange （STE） occurs in the COL. The ozone-rich air mass transported from the stratosphere to the troposphere first becomes unstable, then loses its high ozone concentration. This process usually happens during the decay stage of COLs. In order to understand the influence of COLs on the ozone in the UTLS, statistical analysis of the ozone profiles within COLs, and other profiles, are employed. The results indicate that the ozone concentrations of the in-COL profiles are significantly higher than those of the other profiles between ±4 km around the tropopause. The COLs induce an increase in UTLS column ozone by 32% on average. Meanwhile, the COLs depress the lapse-rate tropopause （LRT）/dynamical tropopause height by 1.4/1.7 km and cause the atmosphere above the tropopause to be less stable. The influence of COLs is durable because the increased ozone concentration lasts at least one day after the COL has passed over Changchun. Furthermore, the relative coefficient between LRT height and lower stratosphere （LS） column ozone is -0.62, which implies a positive correlation between COL strength and LS ozone concentration.

关键词： ozonesonde cut-off low upper troposphere lower stratosphere tropopause

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