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Synoptic Typing and Its Application for Evaluating Climatic Impact on Air Quality in Urumqi
Atmospheric and Oceanic Science Letters, Volume 3 Number 6. Wang Li-Li; Wang Yue-Si; Li Yuan-Yuan - Science Press, 2010An automated procedure employing principal-component analysis and a two-stage cluster analysis was developed to classify the synoptic meteorological conditions prevailing over Urumqi, one of the most heavily polluted cities in the world. Six clusters representing different circulation patterns and air-mass characteristics were classified using surface- and upper-meteorological variables during the heating period from 2001 to 2008, and the relationships between synoptic clusters and air quality were evaluated. The heaviest air-pollution episodes occurred when Urumqi was in either an extremely c ...
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Available online: http://www.iapjournals.ac.cn/aosl/ch/reader/view_abstract.aspx?file_no=AOSL10056
in Atmospheric and Oceanic Science Letters > Volume 3 Number 6 (16 November 2010) . - p.312-318An automated procedure employing principal-component analysis and a two-stage cluster analysis was developed to classify the synoptic meteorological conditions prevailing over Urumqi, one of the most heavily polluted cities in the world. Six clusters representing different circulation patterns and air-mass characteristics were classified using surface- and upper-meteorological variables during the heating period from 2001 to 2008, and the relationships between synoptic clusters and air quality were evaluated. The heaviest air-pollution episodes occurred when Urumqi was in either an extremely cold, strong anticyclone or at the front of a migrating cyclone, both with light winds, wet surface air, and relatively dry upper air. Moderate pollution was seen when Urumqi was in the pre-cold/cold frontal passages with lower temperatures and light winds or moderate anticyclone with relatively warmer, drier air. When Urumqi was at the front of a migrating anticyclone or in a weak anticyclone with moderate winds and most warm, dry air, or in the cold/post-cold frontal passages with relatively strongly northerly airflows and precipitation, relatively good air quality could be seen. These results suggest that air pollution in Urumqi is very closely related to the synoptic meteorological conditions, which provides an important basis for not only the prediction and control of urban air-quality problems here but also for the analysis of the differential impacts of weather and pollution on human morbidity.
Language(s): English
Format: Digital (Free), Hard copyTags: Synoptic meteorology ; Urban zone ; Modelling ; Air quality ; China
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Variations of Terrestrial Water Storage in the Yangtze River Basin under Climate Change Scenarios
Atmospheric and Oceanic Science Letters, Volume 3 Number 6. Ma Quian; Xie Zheng-Hui; Zhao Lin-Na - Science Press, 2010In this study, the water balance-based Precipitation-Evapotranspiration-Runoff (PER) method combined with the land surface model Variable Infiltration Capacity (VIC) was used to estimate the spatiotemporal variations of terrestrial water storage (TWS) for two periods, 1982–2005 (baseline) and 2071–2100, under future climate scenarios A2 and B2 in the Yangtze River basin. The results show that the estimated TWS during the baseline period and under the two future climate scenarios have similar seasonal amplitudes of 60–70 mm. The higher values of TWS appear in June during the baseline period and ...
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Available online: http://www.iapjournals.ac.cn/aosl/ch/reader/view_abstract.aspx?file_no=AOSL10034
in Atmospheric and Oceanic Science Letters > Volume 3 Number 6 (16 November 2010) . - p.293-298In this study, the water balance-based Precipitation-Evapotranspiration-Runoff (PER) method combined with the land surface model Variable Infiltration Capacity (VIC) was used to estimate the spatiotemporal variations of terrestrial water storage (TWS) for two periods, 1982–2005 (baseline) and 2071–2100, under future climate scenarios A2 and B2 in the Yangtze River basin. The results show that the estimated TWS during the baseline period and under the two future climate scenarios have similar seasonal amplitudes of 60–70 mm. The higher values of TWS appear in June during the baseline period and under the B2 scenario, whereas the TWS under A2 shows two peaks in response to the related precipitation pattern. It also shows that the TWS is recharged from February to June during the baseline period, but it is replenished from March to June under the A2 and B2 scenarios. An analysis of the standard derivation of seasonal and interannual TWS time series under the three scenarios demonstrates that the seasonal TWS of the southeastern part of the Yangtze River basin varies remarkably and that the southeastern and central parts of the basin have higher variations in interannual TWS. With respect to the first mode of the Empirical Orthogonal Function (EOF), the inverse-phase change in seasonal TWS mainly appears across the Guizhou-Sichuan-Shaanxi belt, and the entire basin generally represents a synchronous change in interannual TWS. As a whole, the TWS under A2 presents a larger seasonal variation whereas that under B2 displays a greater interannual variation. These results imply that climate change could trigger severe disasters in the southeastern and central parts of the basin.
Language(s): English
Format: Digital (Free), Hard copyTags: Climate change ; Water ; Groundwater ; Scenario ; China
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Simulation of the Bare Soil Surface Energy Balance at the Tongyu Reference Site in Semiarid Area of North China
The performance of a 1-D soil model in a semiarid area of North China was investigated using observational data from a cropland station at the Tongyu reference site of the Coordinated Enhanced Observing Period (CEOP) during the non-growing period, when the ground surface was covered with bare soil. Comparisons between simulated and observed soil surface energy balance components as well as soil temperatures and water contents were conducted to validate the soil model. Results show that the soil model could produce good simulations of soil surface temperature, net radiation flux and sensible he ...
[article]Simulation of the Bare Soil Surface Energy Balance at the Tongyu Reference Site in Semiarid Area of North China
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Available online: http://www.iapjournals.ac.cn/aosl/ch/reader/view_abstract.aspx?file_no=AOSL10049
in Atmospheric and Oceanic Science Letters > Volume 3 Number 6 (16 November 2010) . - p.330-335The performance of a 1-D soil model in a semiarid area of North China was investigated using observational data from a cropland station at the Tongyu reference site of the Coordinated Enhanced Observing Period (CEOP) during the non-growing period, when the ground surface was covered with bare soil. Comparisons between simulated and observed soil surface energy balance components as well as soil temperatures and water contents were conducted to validate the soil model. Results show that the soil model could produce good simulations of soil surface temperature, net radiation flux and sensible heat flux against observed values with the RMSE of 1.54oC, 7.71 W m-2 and 27.79 W m-2, respectively. The simulated volumetric soil water content is close to the observed values at various depths with the maximal difference between them being 0.03. Simulated latent heat and ground heat fluxes have relatively lower errors in relative to net radiation and sensible heat flux. In conclusion, the soil model has good capacity to simulate the bare soil surface energy balance at the Tongyu cropland station and needs to be further tested in longer period and at more sites in semiarid areas.
Language(s): English
Format: Digital (Free), Hard copyTags: China ; Climate ; Climate prediction ; Research ; Natural hazards ; Drought ; Climate simulation ; Soils
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A Quick Report on a Dynamical Downscaling Simulation over China using the Nested Model
Atmospheric and Oceanic Science Letters, Volume 3 Number 6. Yu En-Tao; Wang Hui-Jun; Sun Jian-Qi - Science Press, 2010This paper describes a dynamical downscaling simulation over China using the nested model system, which consists of the modified Weather Research and Forecasting Model (WRF) nested with the NCAR Community Atmosphere Model (CAM). Results show that dynamical downscaling is of great value in improving the model simulation of regional climatic characteristics. WRF simulates regional detailed temperature features better than CAM. With the spatial correlation coefficient between the observation and the simulation increasing from 0.54 for CAM to 0.79 for WRF, the improvement in precipitation simulati ...
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Available online: http://www.iapjournals.ac.cn/aosl/ch/reader/view_abstract.aspx?file_no=AOSL10049
in Atmospheric and Oceanic Science Letters > Volume 3 Number 6 (16 November 2010) . - p.319-324This paper describes a dynamical downscaling simulation over China using the nested model system, which consists of the modified Weather Research and Forecasting Model (WRF) nested with the NCAR Community Atmosphere Model (CAM). Results show that dynamical downscaling is of great value in improving the model simulation of regional climatic characteristics. WRF simulates regional detailed temperature features better than CAM. With the spatial correlation coefficient between the observation and the simulation increasing from 0.54 for CAM to 0.79 for WRF, the improvement in precipitation simulation is more perceptible with WRF. Furthermore, the WRF simulation corrects the spatial bias of the precipitation in the CAM simulation.
Language(s): English
Format: Digital (Free), Hard copyTags: China ; Climate ; Climate prediction ; Research ; Climate simulation
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62 - April 2010 - WWRP 北京オリンピック2008 予報実証/研究開発プロジェクト = WWRP BeijingOlympics 2008 Forecast Demonstration/Research and Development Project (B08FDP/RDP)
is an issue of 気象研究所技術報告. Saito Kazuo; Kunii Masaru; Hara Masahiro - Meteorological Research Institute, 2010This technical report describes modeling activities by the Meteorological Research Institute
(MRI) for the WWRP Beijing 2008 Olympics Forecast Demonstration Project/Research and
Development Project (B08FDP/RDP). MRI participated in B08RDP in collaboration with the
Numerical Prediction Division (NPD) of the Japan Meteorological Agency (NPD/JMA).
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Other titles:
- WWRP BeijingOlympics 2008 Forecast Demonstration/Research and Development Project (B08FDP/RDP)
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Available online: http://www.mri-jma.go.jp/Publish/Technical/DATA/VOL_62/62_en.html
This technical report describes modeling activities by the Meteorological Research Institute
(MRI) for the WWRP Beijing 2008 Olympics Forecast Demonstration Project/Research and
Development Project (B08FDP/RDP). MRI participated in B08RDP in collaboration with the
Numerical Prediction Division (NPD) of the Japan Meteorological Agency (NPD/JMA).Language(s): English, Japanese
Format: Digital (Free), Hard copyTags: Weather ; Meteorology ; Weather forecasting ; China
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The Observed Low CO2 Concentration in the Rongbuk Valley on the Northern Slope of Mt. Everest
Atmospheric and Oceanic Science Letters, Volume 3 Number 5. Zhou Li-Bo; Ma Shu-Po; Li Peng; et al. - Science Press, 2010In the summers of 2006 and 2007, the atmospheric CO2 concentration and the wind speed in the Rongbuk Valley on the northern slope of Mt. Everest were measured by an ultrasonic anemometer with an Li-7500 CO2/H2O gas analyzer. The average CO2 concentration was 370.23±0.59 and 367.45±1.91 ppm in June of 2006 and 2007, respectively. The values are much lower than those at sites with similar latitudes and altitudes worldwide. The observed atmospheric CO2 concentration in Rongbuk Valley can be affected by the transportation of prevailing down-valley winds from the up-valley direction to the observat ...
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Spatial Distributions of Atmospheric Radiative Fluxes and Heating Rates over China during Summer
Atmospheric and Oceanic Science Letters, Volume 3 Number 5. Yang Da-Sheng; Wang Pu-Cai - Science Press, 2010The latitude-altitude distributions of radiative fluxes and heating rates are investigated by utilizing CloudSat satellite data over China during summer. The Tibetan Plateau causes the downward shortwave fluxes of the lower atmosphere over central China to be smaller than the fluxes over southern and northern China by generating more clouds. The existence of a larger quantity of clouds over central China reflects a greater amount of solar radiation back into space. The vertical gradients of upward shortwave radiative fluxes in the atmosphere below 8 km are greater than those above 8 km. The la ...
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Temporal Variations of the Frontal and Monsoon Storm Rainfall during the First Rainy Season in South China
Atmospheric and Oceanic Science Letters, Volume 3 Number 5. Yuan Fang; Wei Ke; Chen Wen; et al. - Science Press, 2010The temporal variations in storm rainfall during the first rainy season (FRS) in South China (SC) are investigated in this study. The results show that the inter-annual variations in storm rainfall during the FRS in SC seem to be mainly influenced by the frequency of storm rainfall, while both frequency and intensity affect the inter-decadal variations in the total storm rainfall. Using the definitions for the beginning and ending dates of the FRS, and the onset dates of the summer monsoon in SC, the FRS is further divided into two sub-periods, i.e., the frontal and monsoon rainfall periods. T ...
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Marine Atmospheric Boundary Layers Associated with Summer Monsoon Onset over the South China Sea in 1998
Atmospheric and Oceanic Science Letters, Volume 3 Number 5. Wang Dong-Xiao; Zhou Wen; Yu Xiao-Li; et al. - Science Press, 2010The variations of the marine atmospheric boundary layer (MABL) associated with the South China Sea Summer Monsoon were examined using the Global Positioning System (GPS) sounding datasets obtained four times daily during May-June 1998 on board Research Vessels Kexue 1 and Shiyan 3. The MABL height is defined as the height at the lowest level where virtual potential temperature increases by 1 K from the surface. The results indicate that the MABL height decreased over the northern South China Sea (SCS) and remained the same over the southern SCS, as sea surface temperature (SST) fell for the no ...
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Interannual Variability of Snow Depth over the Tibetan Plateau and Its Associated Atmospheric Circulation Anomalies
The interannual variability of wintertime snow depth over the Tibetan Plateau (TP) and related atmospheric circulation anomalies were investigated based on observed snow depth measurements and NCEP/NCAR reanalysis data. Empirical orthogonal function (EOF) analysis was applied to identify the spatio-temporal variability of wintertime TP snow depth. Snow depth anomalies were dominated by a monopole pattern over the TP and a dipole structure with opposite anomalies over the southeastern and northwestern TP. The atmospheric circulation conditions responsible for the interannual variability of TP s ...
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Kolmogorov Constants of Atmospheric Turbulence over a Homogeneous Surface
Atmospheric and Oceanic Science Letters, Volume 3 Number 4. Cheng Xue-Ling; Wang Bing-Lan; Hu Fei; et al. - Science Press, 2010In this paper, the authors use ultrasonic data over a homogeneous surface to calculate the Kolmogorov constants of velocity, temperature, CO2, and water vapor. The authors find that the constants are all within the range determined by former experiments and that they are universally independent of the stability.
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Comparisons of Low-Level Circulation Characteristics between ECHAM5/MPI-OM Results and NCEP/NCAR Re-Analysis Data in East Asia
Atmospheric and Oceanic Science Letters, Volume 3 Number 4. Zhao De-Ming; Fu Cong-Bin - Science Press, 2010Regional climate models (RCMs) can provide far more precise information than general circulation models (GCMs). However, RCMs depend on GCM results for re-analysis products providing boundary conditions, especially for future climate scenarios. Meanwhile, the capacity of RCMs to reproduce precipitation is strongly connected to its performance on circulation and moisture transport simulations in the low troposphere, which is the key problem with RCMs at present. In the Regional Climate Model Inter-comparison Project for East Asia (RMIP III), the results of ECHAM5/MPI-OM (the European Centre-Ham ...
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Diapycnal Mixing in Transient Responses of the Atlantic Meridional Overturning Circulation in an Enhanced Freshwater Perturbation Experiment
Atmospheric and Oceanic Science Letters, Volume 3 Number 4. Yu Lei; Gao Yong-Qi; Helge Drange; et al. - Science Press, 2010It has been reported recently that the simulated Atlantic meridional overturning circulation (AMOC) using the coupled Bergen climate model (BCM) showed initial intensity declines followed by gradual recoveries over a 150-year enhanced freshwater input experiment. Stratification-dependent oceanic diapycnal mixing has been hypothesized as a reason for the simulated recovery of the AMOC. This study investigated the role of diapycnal mixing in transient responses of simulated AMOCs. Our results showed that stratification-dependent diapycnal mixing can cause stronger upwelling of deep water in the ...
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Thunder Events in China: 1980-2008
Using data collected at 517 weather stations in contiguous China over the period 1980-2008, characteristics of thunder events have been investigated. These characteristics include geographical distribution, interdecadal variation, annual variation, and seasonal variation. The areas with the highest frequencies of thunder events are located in the central Tibetan Plateau, Yunnan, Guangxi, and Guangdong. The annual number of thunder days increases from northern to southern China. But the frequency of thunder events over mountains and plateaus is much higher than the frequency of events over plai ...
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The Relationship between Total Ozone and Local Climate at Kunming Using Dobson and TOMS Data
Atmospheric and Oceanic Science Letters, Volume 3 Number 4. Wang Jun; Wang Hui-Jun - Science Press, 2010This paper uses Dobson spectrometer total ozone data, Total Ozone Mapping Spectrometer (TOMS) data and radiosonde reports from Kunming, which is located in southwest China, from 1980 to 2008 to analyze the total ozone-climate relationship. The total ozone decadal long-term trend and abrupt change were studied using enhanced Dobson data whose missing data were amended by the TOMS data. Stepwise linear regression was used for the selection of the key factors that influence total ozone, including temperatures, geopotential heights, depressions of the dew point, wind velocities, and total solar ra ...
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