用频率域台阵技术推测2001年昆仑山口西大地震的破裂时间与几何特征

概述频率域远场台阵技术应用于大地震能量辐射源的追踪原理,介绍利用这一技术追踪能量辐射源的一般步骤,并以2001年昆仑山口西大地震为例,分析资料处理中主要参数设置所需要考虑的关键因素. 通过分析埃塞俄比亚/肯尼亚地震台阵（EK台阵）的宽频带波形资料,获得了2001年昆仑山口西大地震的起始破裂点的位置,能量辐射源的空间分布特征,以及破裂持续时间. 根据EK台阵资料的分析结果,2001年昆仑山口西大地震的起始破裂点位于布喀达坂峰东侧（35.92deg;N,91.70deg;E）,破裂持续时间不超过160 s,破裂长度约520 km. 其中,初始破裂点以西为180 km,以东为340 km. 断层西段在布喀达坂峰附近向西南方向发生弯曲,与地表破裂吻合. 断层东段似乎在西大滩断裂附近向东北方向发生弯曲,其方向与西大滩断层的走向一致,但二者相距约30 km. 另外,分析结果似乎表明, 地震断层的西段近乎直立,而东段逐渐南倾.      

混合云在GCM气候模拟中的重要性

文章提出了一种简单且适用于大气环流模式（GCM）的冰云辐射参数化。利用该参数化和UGAMP大气环流模式研究了混合云在GCM气候模拟中的重要性。结果表明，云的相态变化及其所产生的反馈作用对模拟的气候状态有显著的影响。在高纬地区，云的相态变化可使地气系统净辐射增加。而在热带则使净辐射减少。     

NUMERICAL SIMULATION OF EURASIAN TELECONNECTION PATTERN IN ATMOSPHERIC CIRCULATION DURING THE NORTHERN HEMISPHERE WINTER

In this paper, the anomaly of disturbance height field over Northern Hemisphere due to SST anomaly in the tropical Atlantic Ocean is simulated by using the general circulation model of 1AP. A quasi-geostrophic, 34-level spherical coordinate model is also used to compute the distribution of atmospheric circulation anomaly when there is an anomaly of heat source over the tropical Atlantic. The computed results show that, owing to the heat source anomaly over the tropical Atlantic, the EU-pattern anomaly in the winter circulation may be caused. Namely, a ridge will be enhanced over the northwest Europe, a trough will be deepened over Siberia, but a positive anomaly of disturbance height field will be formed over the northeast China, Japan and other areas of East Asia. Moreover, the numerically simulated results show that the above-mentioned EU-pattern anomalies of circulation are due to the propagations of planetary wave train. About 15 days after an anomaly of the heat source over the tropical Atlantic is     

BOUNDARY LAYER GROWTH AND LAPSE RATE CHANGES DETERMINED BY LIDAR AND SURFACE HEAT FLUX IN SOFIA

In this study the results from a boundary layer experiment,conducted in autumn 1991 over a flat,build-up urbanarea in Southeast Sofia,together with some models for mixed layer growth rates are used to investigate the layered struc-ture of the vertical atmospheric stability distribution in the Sofia Valley.Lidar measurements of aerosol layer heightsand morning boundary layer development are combined with surface eddy correlation measurements of kinematic heatand moisture fluxes,profiles of temperature and humidity,wind speed and wind direction.A diagnostic method is pres-ented for determining vertical lapse rates using surface meteorological measurements and lidar returns observed duringthe transition from nighttime stable stratification to daytime convective boundary layer after the sunrise.     

Multivariate Objective Analysis of Wind and Height Fields in the Tropics

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Analytic study of sea-land breezes

1.IntroductionSea---landbreezesaremesoscale,secondarycirculationsforcedbythermalgradients,andtypicallyoccurunderconditionsofweakprevailingbackgroundwinds.Inthedaytime,theland,withasmallerheatcapacity,heatsupmorethanthesea.Asaresult,theairabovetheland...     

Tropical Stratospheric Circulation and Monsoon Rainfall

Interannual variability of both SW monsoon (June-September) and NE monsoon (October-December) rainfall over subdivisions of Coastal Andhra Pradesh, Rayalaseema and Tamil Nadu have been examined in relation to monthly zonal wind anomaly for 10 hPa, 30 hPa and 50 hPa at Balboa (9°N, 80°W) for the 29 year period (1958-1986). Correlations of zonal wind anomalies to SW monsoon rainfall (r = 0.57, significant at 1% level) is highest with the longer lead time (August of the previous year) at 10 hPa level suggesting some predictive value for Coastal Andhra Pradesh. The probabilities estimated from the contingency table reveal non-occurrence of flood during easterly wind anomalies and near non-occurrence of drought during westerly anomalies for August of the previous year at 10 hPa which provides information for forecasting of performance of SW monsoon over Coastal Andhra Pradesh. However, NE monsoon has a weak relationship with zonal wind anomalies of 10 hPa, 30 hPa and 50 hPa for Coastal Andhra Pradesh, Raya     

The interface effect and the formation of a low-level jet along the east side of the rocky mountains

Based upon the analysis of several different causes for the low-level jet along the east side of the Rocky Moun-tains, the concept of “Interface Effect” is established. The basic mechanism for the formation of the low-level jet in North America has been found to be the compression and divergence, under the driving of ageostrophic winds, of the air columns between two surfaces-the ground and the bottom of inversion-which slope with different patterns in a cross-section normal to the jet stream. As a result, the air parcel is accelerated along the stream-line and the anticyclonic shear of the current increased. Also, the diurnal variation of the jet is determined by the interface effect.     

广东清远早、晚稻稻田甲烷排放的观测研究

分析了2003、2004年广东省清远市郊区早、晚稻稻田甲烷（CH4）的排放通量,结果表明：广东清远早、晚稻稻田CH4排放通量的几何平均值2003年为4,38mg·m^-2·h^-1和6．09mg·m^-2·h^-1;2004年为5．17mg·m^-2·h^-1和8．3mg·m^-2·h^-1,土壤有机质含量是造成2003和2004年CH4排放差异的原因之一。水稻品种的不同,CH4排放通量也有所不同,实验表明,水稻品种“七丝尖”的排放通量比品种“金优99”高1．08mg·m^-2·h^-1,产量却只有64％。此外,与相关的测量结果进行初步比较。     

中纬度降雨系统的中尺度结构

一、引言有关中尺度降雨系统结构和机制的知识是很需要的,因为第一,短期降水预报具有重要经济价值;第二,需要将这些系统的影响参数化,以便导入较大尺度大气环流模式中。不幸,除了强雹暴外,对中尺度系统的了解是很贫乏的,这是由于中尺度系统的观测十分困难,日常获得的资料不足以进行恰当的分析,因而必须进行复杂的研究。本文不打算对过去文献进行广泛评论,仅对过去五年来在英国进行的观测研究方面提一些个人看法,并通过个例研