Shanghai Institute of Meteorological science

Shanghai, China

Shanghai Institute of Meteorological science

Shanghai, China
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Han Z.,Shanghai Institute of Meteorological Science | Han Z.,Tongji University | Lu W.,Tongji University | Gu M.,Tongji University | Xie Z.,South China University of Technology
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2017

Based on rigid model wind tunnel tests, wind-induced responses of billboards on high-rise building roof were studied using the time history analysis method, and the influences of unilateral, adjacent bi-lateral, tri-lateral, and quadri-lateral billboard arrangements on the wind-induced responses were analyzed. The results showed that the wind loading on face panels is the maximum under unilateral arrangement, and the minimum under tri-lateral arrangement; the diagonal brace element at the middle position of face panels is most sensitive to wind loading. The internal force response of the vertical prop element near windward side of face panels is larger relatively, the internal force response of the lateral beam element at the middle position of face panels is the largest; under different billboard arrangements, the gust response factor differences of all kinds of elements are not more than 0.1, under the same billboard arrangement, their maximum difference is 0.3; a conservative gust response factor of 1.6 is suggested to calculate the equivalent static wind loads of billboards on high-rise building roof. © 2017, Editorial Office of Journal of Vibration and Shock. All right reserved.


Peng J.,Shanghai Institute of Meteorological Science | Peng J.,Shanghai Key Laboratory of Meteorological and Health | Grimmond C.S.B.,University of Reading | Fu X.,Shanghai Institute of Meteorological Science | And 10 more authors.
Journal of Atmospheric and Oceanic Technology | Year: 2017

To investigate the boundary layer dynamics of the coastal megacity Shanghai, China, backscatter data measured by a Vaisala CL51 ceilometer are analyzed with a modified ideal curve fitting algorithm. The boundary layer height zi retrieved by this method and from radiosondes compare reasonably overall. Analyses of mobile and stationary ceilometer data provide spatial and temporal characteristics of Shanghai's boundary layer height. The consistency between when the ceilometer is moving and stationary highlights the potential of mobile observations of transects across cities. An analysis of 16 months of zi measured at the Fengxian site in Shanghai reveals that the diurnal variation of zi in the four seasons follows the expected pattern; for all seasons zi starts to increase at sunrise, reflecting the influence of solar radiation. However, the boundary layer height is generally higher in autumn and winter than in summer and spring (mean hourly averaged zi for days with low cloud fraction at 1100-1200 local time are 900, 654, 934, and 768 m for spring, summer, autumn, and winter, respectively). This is attributed to seasonal differences in the dominant meteorological conditions, including the effects of a sea breeze at the near-coastal Fengxian site. Given the success of the retrieval method, other ceilometers installed across Shanghai are now being analyzed to understand more about the spatial dynamics of zi and to investigate in more detail the effects of prevailing mesoscale circulations and their seasonal dynamics. © 2017 American Meteorological Society.


Han Z.,Tongji University | Han Z.,Shanghai Institute of Meteorological Science | Gu M.,Tongji University
Tongji Daxue Xuebao/Journal of Tongji University | Year: 2014

Based on the rigid model tunnel test and nonlinear wind-induced response calculation method, the vibration frequencies of initial form-finding state and static equilibrium state, the upward and downward maximum displacement responses under wind load of two saddle tensioned membrane structures are analyzed to study the simplification of similarity parameters. According to the results, it is proposed that, for the tensioned membrane structures without diagonal height difference, similarity requirement of Froude number should be less than λV 2/λL=10/4; for those with diagonal height difference, similarity requirement of Froude number should be less than λV 2/λL=20/4; the quality coefficient should be controlled in the range of 0.8~1.2; and the elastic modulus coefficient should be in the range of 0.5~1.5.


Han Z.,Tongji University | Han Z.,Shanghai Institute of Meteorological Science | Gu M.,Tongji University | Zhou X.,Tongji University
Tongji Daxue Xuebao/Journal of Tongji University | Year: 2015

Based on the aerodynamic wind tunnel test of two saddle tensioned membrane structures, the modal parameters were identified from free responses and responses under wind loading, the using Ibrahim time domain and stochastic subspace identification methods. Besides, the variation of aerodynamic mass and damping with wind direction, wind speed, and pretension were researched, and reasons for the difference between previous research achievements were analyzed by comparison. The results show that the aerodynamic mass changes with the wind direction, reaches the maximum under oblique wind direction, increases with the wind speed increment, and decreases with the pretension increment. In addition, the damping ratio of first order modal increases with the increase of wind speed. ©, 2015, Science Press. All right reserved.


Tan J.,Shanghai Institute of Meteorological Science | Yang L.,Shanghai Meteorological Support Center | Grimmond C.S.B.,University of Reading | Shi J.,Shanghai Institute of Meteorological Science | And 6 more authors.
Bulletin of the American Meteorological Society | Year: 2015

Observations of atmospheric conditions and processes in cities are fundamental to understanding the interactions between the urban surface and weather/climate, improving the performance of urban weather, air quality, and climate models, and providing key information for city end users (e.g., decision makers, stakeholders, public). In this paper, Shanghai's Urban Integrated Meteorological Observation Network (SUIMON) and some examples of intended applications are introduced. Its characteristics include being multipurpose (e.g., forecast, research, service), multifunction (e.g., high-impact weather, city climate, special end users), multiscale (e.g., macro/meso, urban, neighborhood, street canyon), multivariable (e.g., thermal, dynamic, chemical, biometeorological, ecological), and multiplatform (e.g., radar, wind profiler, ground based, satellite based, in situ observation/sampling). Underlying SUIMON is a data management system to facilitate exchange of data and information. The overall aim of the network is to improve coordination strategies and instruments, to identify data gaps based on science- and user-driven requirements, and to intelligently combine observations from a variety of platforms by using a data assimilation system that is tuned to produce the best estimate of the current state of the urban atmosphere. ©2015 American Meteorological Society.


Zhao K.,Nanjing University of Information Science and Technology | Jiang Y.,Nanjing University of Information Science and Technology | Chen K.W.,Nanjing University of Information Science and Technology | Huang L.F.,Shanghai Institute of Meteorological Science
Astrophysics and Space Science | Year: 2016

This paper investigates the dependence of the occurrence frequency of ionospheric upflowing oxygen (O+) ions on the sunspot cycle and geomagnetic activity. We examine the upflows response to the geomagnetic disturbances as well as the influence of the ion energy factor in controlling the magnitude of the occurrence frequency and the net energy flux. We discuss the spatial distribution of the upflow occurrence frequency and construct a regression model as a function of the magnetic latitude. The results show an overall enhancement of the upflow occurrence frequency during magnetically disturbed periods and indicate that the high-occurrence area spreads out from the source regions during magnetically quiet periods. The high-occurrence areas are located at 70° magnetic latitude (mLat) in the dayside auroral oval zone and between 76–80° mLat in the dayside polar cusp region. In the nightside auroral oval zone, these areas are near 60° mLat, penetrating further equatorward to 55° mLat during magnetically disturbed periods. High energy (≥1 keV) upflowing ions are common in the nightside auroral oval zone while low energy (<1 keV) upflowing ions are found escaping from the high latitude dayside cusp region. A Gaussian function is shown to be a good fit to the occurrence frequency over the magnetic latitude. For high energy upflowing O+ ions, the occurrence frequency exhibits a single peak located at about 60° mLat in the nightside auroral oval zone while for low energy upflowing O+ ions, it exhibits two peaks, one near 60° mLat in the auroral oval zone and the other near 78° mLat in the cusp region. We study the solar activity dependence by analyzing the relationship between the upflow occurrence frequency and the sunspot number (RZ). The statistical result shows that the frequency decreases with declining solar activity level, from ∼30 % at solar maximum to ∼5 % at solar minimum. In addition, the correlation coefficient between the occurrence frequency and RZ is 0.9. © 2016, Springer Science+Business Media Dordrecht.


Fang P.-Z.,Shanghai Typhoon Institute of China Meteorological Administration | Gu M.,Tongji University | Tan J.-G.,Shanghai Institute of Meteorological Science | Han Z.-H.,Shanghai Institute of Meteorological Science
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2015

Wall function is preferred to model the low Reynolds-number flow near wall based on the Reynolds-averaged Navier-Stokes turbulent models. Then wall function problem in simulating the atmospheric boundary layer based on the standard turbulent model was investigated. An extra term which considers the extra effects induced by non-uniform and irregular distribution of rough elements such as various structures on the land surface was proposed and appended to the widely accepted standard wall function. The effectiveness and application situation of the proposed term were demonstrated by simulating a neutral wind field with the scale of 1: 300 featured by larger aerodynamic roughness length. The flow around the TTU model in a neutral wind field with the scale of 1: 50 was then simulated. The extra term is shown to be necessary to solve the wall function problem, i.e., the preservation inlet flow boundary conditions in computation domain in both cases ©, 2015, Chinese Vibration Engineering Society. All right reserved.


Zhang Y.,Chinese Academy of Meteorological Sciences | Zhao Y.,Chinese Academy of Meteorological Sciences | Zhao Y.,Shanghai Institute of Meteorological science | Wang C.,Hainan Meteorological Service | Chen S.,Tianjin Climate Center
Theoretical and Applied Climatology | Year: 2016

Assessment of the impact of climate change on crop productions with considering uncertainties is essential for properly identifying and decision-making agricultural practices that are sustainable. In this study, we employed 24 climate projections consisting of the combinations of eight GCMs and three emission scenarios representing the climate projections uncertainty, and two crop statistical models with 100 sets of parameters in each model representing parameter uncertainty within the crop models. The goal of this study was to evaluate the impact of climate change on maize (Zea mays L.) yield at three locations (Benxi, Changling, and Hailun) across Northeast China (NEC) in periods 2010–2039 and 2040–2069, taking 1976–2005 as the baseline period. The multi-models ensembles method is an effective way to deal with the uncertainties. The results of ensemble simulations showed that maize yield reductions were less than 5 % in both future periods relative to the baseline. To further understand the contributions of individual sources of uncertainty, such as climate projections and crop model parameters, in ensemble yield simulations, variance decomposition was performed. The results indicated that the uncertainty from climate projections was much larger than that contributed by crop model parameters. Increased ensemble yield variance revealed the increasing uncertainty in the yield simulation in the future periods. © 2016 Springer-Verlag Wien


Han Z.-H.,Shanghai Institute of Meteorological Science | Han Z.-H.,Tongji University | Gu M.,Tongji University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2015

Based on rigid model wind tunnel tests, the wind load characteristics of double-side and three-side single column-supported billboards were analyzed, and their wind-induced vibration characteristics were studied using the time history analysis method. The results showed that the mean and fluctuating total wind loading coefficients for a double-side billboard have the maximum values of 1.46 and 0.17 under 0°~15° wind direction angle, while those of a three-side billboard have the maximum values of 1.45 and 0.16 under 0° wind direction angle; their mean torgue coefficient reaches the maximum value under 52.5° and 30° wind direction angles, respectively; the resonance energy of node displacement for a double-side billboard is provided by the bending mode perpendicular to the panels, while that for a three-side billboard is provided by the bending modes perpendicular to and parallel to the center line of the triangle composed with panels; the resonance energy of beam torsion angle for two billboards is provided by torsional modes; the most unfavorable condition for bending vibration of two billboards is 0° wind direction angle, and the wind vibration coefficients are 1.51 and 1.59, respectively; while the most unfavorable conditions for torsional vibration of two billboards are 52.5° and 30° wind direction angles the wind vibration coefficient are 1.63 and 2.65, respectively. ©, 2015, Chinese Vibration Engineering Society. All right reserved.


Zhang Y.,Chinese Academy of Meteorological Sciences | Zhao Y.,Shanghai Institute of Meteorological science | Zhao Y.,Chinese Academy of Meteorological Sciences | Chen S.,Tianjin Climate Center | And 2 more authors.
Journal of Applied Meteorology and Climatology | Year: 2015

Projections of climate change impacts on crop yields are subject to uncertainties, and quantification of such uncertainty is essential for the effective use of the projection results for adaptation and mitigation purposes. This work analyzes the uncertainties in maize yield predictions using two crop models together with three climate projections downscaled with one regional climate model nested with three global climate models under the A1B emission scenario in northeast China (NEC). Projections were evaluated for the Zhuanghe agrometeorological station in NEC for the 2021-50 period, taking 1971-2000 as the baseline period. The results indicated a yield reduction of 13% during 2021-50, with 95% probability intervals of (-41%, +12%) relative to 1971-2000. Variance decomposition of the yield projections showed that uncertainty in the projections caused by climate and crop models is likely to change with prediction period, and climate change uncertainty generally had a larger impact on projections than did crop model uncertainty during the 2021-50 period. In addition, downscaled climate projections had significant bias that can introduce significant uncertainties in yield projections. Therefore, they have to be bias corrected before use. © 2015 American Meteorological Society.

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