INTRASEASONAL OSCILLATIONS IN ASIA TO WESTERN PACIFIC REGION IN BOREAL SUMMER: CONTRASTIVE ANALYSIS FOR ACTIVE AND INACTIVE YEARS OF TROPICAL CYCLONES

Comparative analysis is carried out by using finite-domain power spectrum and lagged regression methods for the propagating characteristics and air-sea interaction processes of intraseasonal oscillations (ISOs) in the Asia to western Pacific (AWP) region during the boreal summer between the active and inactive tropical cyclone (TC) years from 1979 to 2004.The results show as follows.(1) There exist more significant eastward propagating characteristics of the ISO in the active TC years over the whole AWP region.The ISOs of convection propagate zonally with more eastward extension in the years with active tropical cyclone activities,during which the 20-60-day period is strengthened,western Pacific becomes an area with evident characteristics of the propagation that is closely related to TC activities.(2) The air-sea interaction processes are the same in both active and inactive TC years,and the energy exchanges between the air and the sea play a role in maintaining the northwestward propagation of ISOs.(3) The air-sea interaction is more intensive in the active TC years than in the inactive ones.It is particularly true for the latent heat release by condensation as the result of convection,which may be one of the reasons resulting in significant differences in characteristics of ISOs between the active and inactive TC years.     

物理守恒律保真全球谱模式辐射—云—对流过程的改进

辐射—云一对流相互作用的正确和合理描述是改进湿物理过程描述和数值模式的重要方面.在一个物理守恒律保真的全球模式中引入描述更细致的云参数化方案和辐射参数化方案,对6个30天实时资料数值积分进行分析.结果表明,通过云参数化方案中云描述的细化,改进了模式对云分布、云量、以及云水、云冰不同相态的模拟;辐射方案中对这些云水物质的...     

中国实施铁路电气化的节能减排量估算

基于中国铁路部门逐年统计数据,计算了1975-2007年中国电气化铁路带来的逐年节能量和CO2、烟尘、SO2、CO、NOx与CnHm的直接减排量,并分析了其变化特点.结果表明,33年来电气化铁路使得中国铁路运输行业年均节省123.0万t标准煤的能源消耗,节能量年均增长13.9万t标准煤;CO2、烟尘、SO2、CO、NO...     

A Case Study of a Typical Dust Storm Event over the Loess Plateau of Northwest China

Enhanced observational meteorological elements,energy fluxes,and the concentration of dust aerosols collected from the Semi-Arid Climate Observatory and Laboratory(SACOL) during a typical dust storm period in March 2010 at Lanzhou were used in this paper to investigate the impact of dust aerosols on near surface atmospheric variables and energy budgets.The results show that the entire dust storm event was associated with high wind velocities and decreasing air pressure,and the air changed from cold and wet to warm and dry and then recovered to its initial state.The response of energy fluxes occurred behind meteorological elements.At high dust concentration periods,the net radiation was significantly less in the daytime and higher at night,while the heat fluxes displayed the same trend,indicating the weakening of the land-atmosphere energy exchange.The results can be used to provide verification for numerical model results in semi-arid areas.     

真实基流中非线性Rossby波演变特征(二):能量、结构演变及初始场影响

针对非线性的准地转正压位涡方程,利用自行设计的差分格式和高斯函数拟合得到的真实基流分布,数值研究了线性和非线性Rossby波流场结构和总能量的演变以及初值对总能量演变的影响.发现在非线性的真实基流中,线性和非线性Rossby波的相对总能量出现振荡型增长或衰减,非线性波动的振荡周期明显小于线性波动,非线性项不仅抑制能量的...     

Theoretical Prediction of Gibbs Free Energies of Formation for Crystalline α-MOOH and α-M2O3 Based on a Linear Free-Energy Relationship

In the present study, the modified Sverjensky–Molling equation, derived from a linear-free energy relationship, is used to predict the Gibbs free energies of formation of crystalline phases of α-MOOH (with a goethite structure) and α-M2O3 (with a hematite structure) from the known thermodynamic properties of the corresponding aqueous trivalent cations (M3+). The modified equation is expressed as ΔG0f,MVX=aMVXΔG0n,M3++bMVX+βMVXγM3+, where the coefficients aMVX, bMVX, and βMVX characterize a particular structural family of MvX (M is a trivalent cation [M3+] and X represents the remainder of the composition of solid); γ3+ is the ionic radius of trivalent cations (M3+); ΔG0f,MVX is the standard Gibbs free energy of formation of MvX; and ΔG0n,M3+ is the non-solvation energy of trivalent cations (M3+). By fitting the equation to the known experimental thermodynamic data, the coefficients for the goethite family (α-MOOH) are aMVX=0.8838, bMVX=?424.4431 (kcal/mol), and βMVX=115 (kcal/mol.?), while the coefficients for the hematite family (α-M2O3) are aMVX=1.7468, bMVX=?814.9573 (kcal/mol), and βMVX=278 (kcal/mol.?). The constrained relationship can be used to predict the standard Gibbs free energies of formation of crystalline phases and fictive phases (i.e. phases that are thermodynamically unstable and do not occur at standard conditions) within the isostructural families of goethite (α-MOOH) and hematite (α-M2O3) if the standard Gibbs free energies of formation of the trivalent cations are known.     

饱和孔隙介质中非均匀震电平面波

采用描述地下流体饱和孔隙介质中弹性波与电磁场耦合现象的Pride方程组,利用Helmholtz分解,求解了非均匀震电耦合平面波解,推导了流体饱和孔隙介质中传播的非均匀震电平面波的能流表达式,讨论了非均匀震电平面波的能量特征.结果表明,非均匀震电平面波的平均能流在传播矢量和衰减矢量构成的平面内传播,伴随电磁场对纵波模式的能流没有贡献.当动电耦合系数为0时,震电平面波的能流表达式可退化为Biot弹性波的能流表达式。     

地表能量变化对多年冻土活动层融化过程的影响

利用青藏高原北部唐古拉综合观测场2006-2008年辐射平衡及活动层温度观测资料,分析了高原北部地表能量变化对活动层融化过程的影响.结果显示：该地地表能量具有明显的季节变化特征,总辐射、净辐射、土壤热通量及地面热源强度6-7月最大,11-12月最小;研究时段土壤热通量年平均值0.12MJ.m-2.d-1,活动层土壤以吸...     

时间域拉东变换的实现及其改进

介绍了时间域拉东正反变换的基本原理及该项技术在地震数据处理中的应用。以Ng和Perz的算法为基础,以开发地震勘探处理与解释系统为实例,解决了实验中遇到的拉东正变换时收敛精度、反变换数据无损还原和截断信号引起的能量扩散、低信噪比情况下的滤波等问题,进一步研究了改进算法在其他地形下应用问题。     

植被影响下坡面侵蚀临界水流能量试验研究

坡面侵蚀临界水流能量是反映土壤抗蚀作用强弱的重要特征值.利用人工模拟降雨试验,定量研究了在45mm/h、87 mm/h和127 mm/h降雨强度下、20°陡坡面裸地、草地和灌木地的坡面侵蚀临界水流能量.结果表明,不同植被条件下坡面输沙率随径流切应力、单位水流功率和断面比能的增大而增大,有良好的响应关系.裸地、草地和灌木...