Velocities of elastic waves andv P/v S ratios in dry and water-saturated rock samples at high pressure

Elastic wave velocities and the ratiov _P/v _S were studied for dry and initially saturated samples of carbonate and crystalline rocks at pressures to 2 kbar. In initially saturated samplesv _P increases in crystalline rock, whereas in sedimentary rock it may either increase or decrease with increasing pressure. Under the same conditionsv _S remains approximately constant in crystalline rocks and decreases in sedimentary samples. The ratiov _P/v _S as a function of pressure increases in dry rocks and decreases in saturated ones. Saturated samples always have higherv _P/v _S ratios than dry ones. It appears that the geometry of the pore space influences the acoustic properties of saturated crystalline rocks.     

Upper mantle structure of the Apulian plate from Rayleigh waves

Phase velocities of Rayleigh waves for the Adriatic Sea area are obtained in the period range 25–190 sec along the path (l'Aquila-Trieste) AQU-TRI and 20–167 sec along the path (Trieste-Bari) TRI-BAI.The phase velocities are systematically higher than the known values for the surrounding regions. The data inversion indicates the presence of a lithosphere typical of stable continental areas with clear high-velocity lid (V _s 4.6 km/sec) overlying a well developed low velocity zone (V _s 4.2 km/sec).P. F. Geodinamica C.N.R., Roma Pubbl. N. 189.     

The dynamical and liquid water structure of the small cumulus as determined from its environment

This paper examines the evidence for the model of a small cumulus cloud represented as a quasi static but turbulent entity, growing on the upshear side and decaying on the downshear side. While the air just outside the cloudy outline is, on average, stationary relative to the embedding airmass, there is a slight flow, upwards and forward as though the updraft has induced upward motion in the clear air outside the cloud, on the growing side. On the decaying side the motion is downwards and away from the cloud.This is a flow pattern which is not consistent with the air flowing around the cloud as it moves forward but it agrees well with the picture given. Decayed remnants of cloud are found throughout the air previously occupied by the cloud. The cloud outline moves through the embedding air at a velocity which is almost as large as the relative motion of the subcloud feeding airflow (which is almost free from internal wind shear in strong convection).The mixing of dry air from above the inversion yields the observed diluted liquid water content in small cumuli, if such mixing is allowed to proceed until the cloud density equals that of the surrounding air. Quantitative conditions relating the liquid water to inversion temperature and moisture changes, and to the stability of the environment are presented. The strong vertical mixing from the top of the cloud downwards is important to microphysical processes.     

On mixing processes in cumulus clouds

An examination is made of the hypothesis that internal cloud properties are determined by the mixing of dry air from above the cloud top and cloud base air in such a way that the mixture is neutrally buoyant with respect to the clear air environment at each level. It is concluded that the resulting mixture is much drier than is actually observed. Comments are made about observed cloud properties which need to be taken into account in any model of the mixing process.     

云南民族语地名探析

云南有２５种世居的少数民族，是全国少数民族最多的省，也是民族语地名语种最多的省。云南被称为“地名博物馆，，民族语地名有其典型性。云南的民族语地名有很多特点，但并不特殊，在其他地方也似曾相识。本文以一个省为单元，对少数民族语地名进行全面综合研究，探讨民族语地名与地理环境、历史发展的关系及各种民族语地名之间的关系。     

赤道太平洋对流活动异常对我国夏季降水和气温的影响

利用月平均ＯＬＲ、降水和气温资料,研究了ＥＮＳＯ期间赤道太平洋对流活动与我国夏季降水和气温的关系。结果表明：春季、夏季中、西太平洋对流活动异常与我国夏季江淮地区的降水有密切关系;春季和前一年冬季西太平洋对流活动异常与东北地区夏季降水有显著相关。前一年冬季中、西太平洋对流活动异常与我国降水的显著相关区是不同的,前者为华南、西南地区,后者为东北至内蒙古一带。气温与同期中、西太平洋对流活动的相关不显著。     

Estimation of Sensible Heat Flux from Surface Temperature Wave and One-Time-of-Day Air Temperature Observation

By means of the algorithm presented here, the temporal course H(t) and the daily mean H¯ of the sensible heat flux H can be estimated from measurements of the thermodynamic surface temperature (as a function of time) and from a one-time-of-day air temperature observation. In addition to these temperatures, one needs estimates for daily mean wind speed, for the roughness lengths of momentum and heat transfer, and for the displacement height. First, a quite general solution of the equation for heat conductance (equation for the vertical profile of potential temperature (z,t)) in the dynamic sublayer will be presented. The undetermined parameters in this solution will be defined with the aid of the above mentioned measurements. The influence of horizontal advection will be taken into account. After that, the sensible heat flux can be evaluated from the temperature difference between surface and air with the well known resistance formulae. In this paper the algorithm is derived for areas with homogeneous surfaces, i.e., with uniform surface temperatures. Finally, the method will be verified by measurements taken during the field campaigns HIBE 89 (Hildesheimer Börde in Germany) and EFEDA 91 (Spain). The root mean square errors (RMSE) for the comparison between measurement and model with regard to the temperature difference of surface and air amount to one or two degrees Kelvin, and the error of H¯ reaches 10 to 25 per cent. The method can be used to determine the sensible heat flux from measurements of surface temperatures by satellites (e.g., METEOSAT), but can also be applied to ground based measurements. For instance, horizontal temperature advection can be estimated from measurements at a single location, especially if more than one near-surface air temperature is available. The procedure can be generalized for larger areas, which consist of various surface types with different surface temperatures. This generalization of the algorithm is in progress and will be addressed in a subsequent paper. It will allow us to improve the estimates for H(t) by means of temperature measurements from, e.g., NOAA/AVHRR or LANDSAT/TM, taking into account the heterogeneity of the area that is contained in one METEOSAT pixel.     

对流层高层偏北气流在梅雨暴雨中的作用

文中对江淮梅雨暴雨过程中的高低空流场特征及物理过程进行分析．结果表明：对流层上部青藏高原东侧常有高空偏北大风轴汇入南亚东风急流中．在这支强北风轴北端发现高空辐散和辐散的增长．亦即有利于低层辐合上升的持续、发展和加强;表明了低层西南急流与高空青藏高压东侧的偏北强风轴之间的次级环流圈,有利于梅雨暴雨的持续．     

NUMERICAL EXPERIMENT OF IMPACT OF SEA SURFACE TEMPERATURE IN SOUTH CHINA SEA AND WARM POOL/WEST PACIFIC ON EAST ASIAN SUMMER MONSOON

By using the NCAR CCM1 model, we have designed six sensitive experiments, which areincreased and decreased SST (sea surface temperature) by 1℃ each in the SCS (South China Sea)and in the West Pacific warm pool, increased and decreased SST by 1℃ in the warm pool withincreased SST by 1℃ in the SCS. All experiments are integrated from April to July. Comparingwith the control experiment, we have analyzed the anomalies of the wind field at the upper andlower layers, the anomalies of the seasonal variability of the monsoon and precipitation for eachexperiment. In the result, we have found that the SST anomaly (SSTA) in the SCS greatly affectsthe seasonal variability of the SCS monsoon and precipitation in China, especially during the coldperiod of SST in the SCS. The impact of SSTA in the warm pool on SCS monsoon is also found.but is weak as compared to the effect of SST anomaly in the SCS. Besides, its impact on rainfall inChina is uncertain.     

长江三峡坝区汛期降水的气候背景分析及其与北太平洋海温的关系

对长江坝区汛期降水的气候背景进行了分析后指出：坝区汛期降水异常与ＥＡＡ相关链,特别是东亚这一段遥相关型有明显联系,进而探讨了它与前期北太平洋海水温度的关系。