Meso-scale meteorological numerical model WRF (Weather Research and Forecast) and the Fitch Wake model are adopted to reveal the intension and patch range of TWE (turbine wake effect) in various atmospheric stability, as well as the impact of different turbine configuration on utilization efficiency of wind energy. Case studies are conducted over Poyang Lake region. The results are as followed. Horizontally, the patch range of a single wind turbine’s TWE can reach 4 to 10 km downward, with a reduction in wind speed ranging from −0.2 to −1.2 m/s under different atmospheric instability. The reduction in wind speed is more severe with more turbines on the stream track. Among the five cases with different turbine location configuration, the wind speed reducing effect in square case (intensively distributed) is much more apparent than others, while the wind speed in TWE patch tends to recover quickly in hollow diamond case (sparsely distributed). Compared with unstable atmospheric stratification, the TWE under stable atmospheric stratification has a longer patch range, because the turbulent exchange of momentum is intenser in unstable stratification than that in stable stratification. Vertically, the QKE (twice of turbulent kinetic energy) at the wind turbine spot peaks in the core. QKE increases to its maximum value of 19 m²/s² and then decreases to around zero. The maximum QKE appears at the level of about 90 m above ground level, while the vertical impact of TWE can be traced to a height of 1.1 km.

Data of EBEX-2000 was used to analyze the influences of Schotanus correction and Webb correction on turbulent heat fluxes and the governing factors of the two corrections. Furthermore, considering turbulent heat flux corrections, impact factors of energy balance ratio (EBR) were discussed and reasonable interpretations were provided according to actual weather and topographic condition. Results show that the magnitude of Schotanus correction varies from ?40 to 2 W/m², with a significant diurnal variation, and the mean value of which is ?8 W/m². The two dominant factors of Schotanus correction are atmospheric stability and vertical gradient of water vapor. The magnitude of Webb correction varies from ?5 W/m² to 14 W/m² with a mean value of 1.8 W/m², which is much smaller than that of Schotanus correction. Webb correction is positive for daytime and negative for nighttime, and it is mainly affected by Bowen ratio and specific humidity, having little probability to reach a great value. EBR calculated using a 30 minutes average is about 0.63 with large diurnal variations and dispersion, and decreases rapidly with a sudden rise of soil water content.

Data of turbulence, net radiation and temperature profiles obtained in International Energy Balance Experiment (EBEX-2000) are used to study characteristics of turbulence cospectra, temperature profiles and turbulent fluxes at 8.7 m and 2.7 m in the atmospheric surface layer. Interaction of large eddies with local turbulence in a disturbed surface layer induced by patch-to-patch irrigation is emphasized, as well as their influence on turbulent fluxes. Results indicate that peak frequencies of cospectra in the low frequency range at the two levels are well consistent, revealing that low frequency turbulence obeys the OLS law. High frequency turbulence obeys the local isotropy theory. Spectral energy in low frequency range is greatly enhanced by large eddies, and this enhancement is more notable at 8.7 m than that at 2.7 m. Multiple peak frequencies are observed at low frequency range of cospectra, and their scales correspond well with thermal heterogeneous scale of the underlying surface. Three dominant scales of these large eddies are 800, 400 and 200 m. Furthermore, large eddies have greater influence on turbulence at higher levels than lower levels and in unstable atmospheric surface layer than stable atmospheric surface layer.

Two improvements were introduced to the Peking University model of atmospheric environment (PUMA) to expand its utility. First, a new generation of mesoscale meteorological model WRF was adopted to provide meteorological fields for PUMA; second, Grisogono scheme, a non-local vertical turbulent mixing parameterization, was introduced into PUMA. Both WRF and PUMA were evaluated with observed data over Shenyang China in winter. Under convective boundary layer at noon, PUMA was improved by Grisogono scheme. The diurnal cycle of SO₂, with low values during daytime and high values during nighttime, was negatively related to the cycle of boundary layer height according to the simulation. The improved PUMA can be applied to atmospheric environment forecasting and warning.

The concentration and dose model on chemical agents diffusion or the toxic clouds diffusion model over complex terrain(CDM) is established, which can be used to assess and predict atmospheric pollution chemical accident hazard, and provides fast, intuitionistic and quaniticational decision information for emergency. Contaminated field, contaminated rate, contaminated area, and contaminated depth may be computed in a few minutes. The comparison of field experiment results with numerical simulation results shows that contaminated field, contaminated rate, and contaminated depth are consistent on the whole, and the relative error of dose at different distance is less than one time. The mean relative error is 20.6%, and the relative error of contaminated depth are ?26.3% and 10.2% respectively at 0.66 g?s/m3 and 0.24 g?s/m³ dose. The comparison of CDM simulating results with water tank experiment results shows that they are similar highly in neutral atmosphere or stable atmosphere.

The exploration analysis and correlation analysis were done using the Air Quality data and synoptic radio sonic data in Beijing, 2007 to illustrate the relationship between the spatio-temporal distribution of PM₁₀ mass concentration and the meteorological condition and its diurnal and seasonal variation, The results show that the synoptic condition in the atmospheric boundary layer dominates the accumulation, transportation, dilution and sinking processing. There is a significantly negative correlation between PM₁₀ mass concentration and synoptic conditions such as height of Atmospheric boundary Layer (ABL) and wind speed while positive correation between PM₁₀ mass concentration and temperature near ground surface pressure. Besides, the correlation varies with seasons; The relationship between PM₁₀ mass concentration and wind speed can be described by a U-curve which obey a binomial model. The PM₁₀ mass concentration observation data in November 2007 shows a minimum records with wind speed of 4.1 m/s.

The authors coupled the heat convection caused by water vertical movement to the traditional soil heat conduction equation. Utilizing the data collected at Jinta Oasis from June 11 to 15, 2005, the thermal diffusivity and the liquid water flux density were calculated respectively. Based on the results of soil thermal diffusivity, taking the soil layer at the depth of 0.05 m as the upper boundary, the authors modeled the temperature for the soil layer at the depth of 0.10m and 0.20m by means of the two methods mentioned above, and compared the surface energy closure factor which calculated by the two methods. The results show that the thermal conduction-convection algorithm can estimate the soil temperature well and the role of thermal convection can improve the soil surface energy closure factor 6% or so.

In the campus of Peking University, there are Weiming Lake, other water body, and agminate green space in the north part, differing significantly on the thermodynamic properties from the south teaching and living part which consist mainly of buildings and roads. In order to study the meteorological and comfort fields in summer, numerical simulation using the city canopy model of Peking University is carried out. In September it is more cool and comfortable in the north of the campus than in the south, and the temperature difference can reach 6. 7℃ at 15: 00. The temperature of road surface is higher than other surfaces because of the zero latent heat flux. The temperature difference can reach 10. 6℃ between road and water. The air specific humidity is higher in the north. The temperature distribution leads to a divergence air flow at 15:00. Thermohygrometric index (THI) is introduced to access human comfort, according to which 50% time of a day is at the “hot”level above road while above other surfaces only 20% of a day is at this level. This work can provide the scientific basis for assessing the meteorological effect of campus environment designs.

The analysis data include the PM₁₀ (particulate matter with aero-dynamic diameter smaller than 10 μm) mass concentration, AWS (automatic weather station) data and radio-sounding data at Beijing Observatory in November 2007, to find out the relationship between PM₁₀ mass concentration and bulk Richardson number. The result got by statistical analysis software SPSS 15. 0 shows that there is strong correlation between PM₁₀ mass concentration and surface meteorological factors, as well as bulk Richardson number in atmospheric stable stratification condition in Beijing area. The linear correlation between PM₁₀ mass concentration and wind speed ( r= - 0. 65, α= 0. 01) is significant, and the same as that PM₁₀ mass concentration and relative humidity (r = 0. 69, α= 0. 01). There is a nonlinear relationship like logarithm ( R = 0. 42) between PM₁₀ mass concentration and bulk Richardson number of ground to 450m layer. Besides, some independent sample tests also suggest that the regression model simulates the PM₁₀ mass concentration well when using the radio-sounding data.

Based on the characteristics of atmospheric field observation, the influence of man-made operating error and instrument error is compared, and conclusion is drawn that operating error predominates in this process. Then frequently-used and available methods for processing data of double-theodolite anemometry are presented, and their applicability is analyzed. However, none of those methods can be suitable for use unconditionally while limited maximum error is given. Consequently, a joint method based on the advantages of all available methods is introduced, which can be applied to most comprehensive and extensive conditions. Finally, compared with base-line anemometry by using the observation data from Duhu at 10:00 on 16 August, 2007, and the advantage of the joint method is displayed.

By extending Modified Soil-Plant-Atmosphere Scheme (MSPAS) to include an effective parameterization scheme of atmospheric radiation transfer, a two-dimensional model was built, which allows physically realistic simulation of modified land atmosphere interactions model (MLAIM) and relevant feedback mechanisms. After modification of parameterization schemes of soil water transfer,atmospheric surface layer turbulence transfer,and vegetation processes, the simulation results were validated by using observational data in HEIFE experiment.Results indicate that the modified MLAIM can simulate well physical processes in land atmosphere interactions.As a result, MLAIM can be used as an effective method to simulate land surface energy budget in oasis and desert,and to study the regional climate effect of oasis.The authors discussed the causes of oasis “cold island effect" and “wet island effect",and focused on oasis's influence on its surrounding desert.Results indicate that the water vapor transport from oasis to desert serves as the most important factor which affects the land surface energy budget in desert as well as the regional climate in oasis's surrounding areas.

Based on the meteorological data from five weather stations of Shenyang during 1959-2005, the change trends and characteristics of the temperature, precipitation, relative humidity, wind speed of urban and rural areas of Shenyang are analyzed. The effect of urbanization on local climate in Shenyang is discussed. The results show that: 1 in recent 47 years, the temperature of Shenyang has increased remarkably, with the most obvious warming occurring in winter and spring, and a little warming trend in summer. Meanwhile, the warming trend of rural areas increases slightly faster than that of urban areas. 2 The change trends of precipitation, relative humidity, wind speed of Shenyang decreases mostly, of which wind speed decreases most and precipitation decreases least. Compared with relative humidity and wind speed, the seasonal change trend of precipitation is complex, with a little increase in winter. The analysis indicates that the development of urbanization in Shenyang has a serious effect on local climate, especially on the climate of rural areas. Furthermore, the effect of urbanization on temperature and wind speed is more obvious and direct than that on relative humidity and precipitation.

An integrated and flexible numerical model has been established to simulate and study the evaporation, transpiration and evapotranspiration mechanism of moisture on land, surface with complex vegetative cover. To better simulate this process, the authors apply some reasonable modifications to the parameterization of edaphic process too. The model is used to simulate the process of Zhangye station during IOP2 of HEIFE, and the results are generally in good agreement with observations. It indicates that the model developed can be used to study the interaction between land surface and atmospheric boundary layer over arid and semi, arid regions. Thus it can be used on evaluating the environment and shaping measures for sustainable development.

The meso-scale urban atmospheric boundary layer model of Peking University, with three-dimensional complex topography, was improved by introducing the second generation land-surface model, which paid more attention to the effect of vegetable coverage when computing land-surface water balance. The improved model was used to simulate temperature, wind and humidity fields over Beijing in summer. It is found that the model can provide acceptable results compared with observations. The simulation results are important to understand the local climate over Beijing area and the feature of diffusion of pollutants, and are helpful for making practical urban design.

The non-hydrostatic mesoscale model MM5.V3 is used to simulate the wind field, temperature field etc. of the atmospheric boundary layer over Beijing Area with the mesh resolution of 1km. The simulation results show that the numerical model can successfully simulate the heat island effect and the wind field and temperature field, which are affected by the complicated topography and urban heat island. The results show that: (1) The surface temperature in the central Beijing is 6--8℃ higher than that in the suburbs. (2) Due to the unique topography the wind of Beijing area during the day time is southern anabatic wind and is northern katabatic wind in the night.

The wind fields and temperature fields data provided by "D files" from 14 surface observation stations around Beijing area are used to produce the mean wind fields and the mean temperature fields over Beijing area in summer and winter. Such results are gotten: (1) Due to the unique topography the wind of Beijing area during the day time is southern anabatic wind and in the night is northern katabatic wind in summer. In winter, this phenomenon disappears due to the affect of the strong synoptic systems. (2) In summer, Haidian and Fengtai lie in an area with high temperature. These areas are the main are as of the Urban Heat Island over Beijing area. In winter Haidian and the area north to Haidian are high temperature areas during the night.

The turbulent data were measured using three-dimensional sonic anemometers/thermometers above a forest canopy, in the Changbai Mountains of northeast China. Turbulence length scales, dissipation rates and structure parameters above the forest canopy were calculated using the eddy correlation method. Results show that the turbulence characteristic length scales for momentum are negative interrelated with Z/L number; the turbulence characteristic length scales for heat is positive interrelated with Z/L number in unstable air and that is negative interrelated with Z/L number in stable air. The agreement between the momentum and heat dissipation rates calculated directly from the w spectrum(the turbulence spectral method)and indirectly from equations(15)(16)are quite good. The dimensionless turbulence structure functions C²_vz^2/3σ_w^-2 and C²_Tz^2/3σ_T^-2 are functions of Richardson number in stable and unstable air. Turbulence structure parameters C²_T has a direct linear bearing on the sensible heat flux w'T'.

A transfer model is established, which can be used to study the interaction between the land surface physical processes of inhomogeneous region and the structure of atmosphere boundary-layer over urban and rural terrains. The model has simulated surface heat flux, surface temperature, temperature profiles, height of mixture layer and so on. And the differences between urban area, suburban area and rural area have been compared. This model mainly depends on the parameters below: surface albedo, surface roughness coefficient, moisture available coefficient of soil, thermal capacity and thermal diffusion coefficient of errain,cloudage. The result shows that this model can simulate the structure and eigenvalues of atmosphere boundary layer and their changes in a day. Parameters used in this model aim at Beijing City, and the time is at the beginning of September. To other cities, or other time, the parameters should be adjusted accordingly. In addition, being adjusted, the model can also be used for other homogeneous and inhomogeneous terrains.

The aerodynamic roughnees length Z₀, the zero-plane displacement d, the momentum drag coefficient C_D, water and heat drag coefficient C_H are calculated by using turbulence data and wind, temperature profile data observed in Changbai Mountain forest. The causes of the error in the method of calculating d and Z₀ are also discussed. The method based on the mass conservation principle is a practical one to calculate the aerodynamic roughness length and zero-plane displacement over tall vegetations. In Changbai Mountain forest, the roughness length Z₀ is about 1.6+-0.25m and the zero-plane displacement d is about 19.5+-1.38m. Drag coefficients C_D and C_H have a good relation with stability under unstable condition, and the average values of C_D and C_H are 6.6×10^-3 and 6.4×10^-31 in the neutral atmosphere, respectively.

Turbulence data and wind, temperature profile data areused to analyze turbulence structure within and above Changbai Mountain Forest. The normalized wind profiles within Changbai Mountain Forest is considered to be exponential: U(Z)/U (h)= exp [α₁(Z/h-1)], where α₁=2.05. The normalized momentum exchange coefficient within the canopy is proved to be exponential: K_m=(Z)/K_m (h)= exp [α₂(Z/h-1)] ,where α₂=5.2. Above the canopy, the longitudinal and lateral turbulence intersity i_u,i_v have almost the same value but the vertical turbulence intensity i_w is smaller than i_u, i_v because of the influence of the canopy. Within the canopy, i_u, i_v, i_w are similar in magnitude but larger than those above the canopy because of the big LAI and the influence of the canopy, the ground and the trunk. The spectral densities of the velocity components in the inertial subrange still can be described by the way in the flat terrain but the slopes show that they are significantly morenegative than -2/3 expecially within the canopy. In addition, the second peak of the spectrum within the canopy occurs and may becaused by wake-turbulence generation. From the data and the locally isotropic analysis, Taylor′s frozen-eddy hypothesis and locally isotropy are invalid within the canopy.

A numerical model is developed for simulating microclimate of bare soil, which is incorporated in one-dimensional boundary layer model. The sensitivity of the scheme to several soil physical parameters is evaluated. Numerical simulated results indicate that the most important soil characteristic parameter is the soil moisture, and next is the surface albedo, which regulates the heat balance and the strength of the fluxes of heat and moisture between thermosphere and the ground.

By using the one dimensional soil-vegetation-atmosphere coupled numerical model the processes of land surface evapotranspiration for the difference vegetation cover factor in the arid and semi-arid region of Northwest China (around 38N, 105E) are studied. The evapotranspiration process and the soil moisture content in the soil-vegetation-atmosphere system is simulated and compared between simulated and observed the soil moisture content for different vegetation shielding factor. The results indicate that the evapotranspiration can be divided into three stages in accordance with the variations of the soil moisture near the surface, and brought to light the each other transition processes of the heat balance components at the underlying surface. The preliminary results of the numerical simulation indicate that the soil properties and vegetation shielding factor are the most important influence factor in this process, and the land surface process model is capable of predicting the thermal and evapotranspiration processes and siutable to climate study.

Advances a parameterized modelto study the influence of vegetation on the moisture-heat exchange at near-ground layer. With this model, the moisture-heat exchange between earth surface and atmosphere is studied under conditionsof different vegetation and soil moisture regime. The results show that the simulation states of temperature, moisture, radiation and energy balance are reasonable, and thus, this parameterized model is capable of using to study mesoscale meteorological modeling, climate modeling and environmental ecology.

In this paper, the two-dimensional numerical model are used for simulating the profiles of the potential temperature and specific humidity over homogeneous Gobi underlying surface under convective conditions. This result explains the observed fact that most of the profiles of the potential temperature and specific humidity. The model also gives a fair description of the time variation of the profiles of the potential temperature and specific humidity and the depth of the mixed layer. Comparison with observation shows that the results obtained from the numerical model are in good agreement with observations of the potential temperature and specific humidity, including the change of the depth of the mixed layer with time.

The development and structure of the nocturnal atmosphere boundary layer over Gobi are studied using one dimensional numerical model. Typical features of the development and the formation of the inversion and the slope flow wind during nocturnal surface cooling condition are obtained. The simulation results are compared with the observational data and are in good agreement with ones.