Identification of motion parameters from spatio-temporal atmospheric temperature patterns

In near-calm conditions it is difficult to make direct measurements of atmospheric advection reliably and cheaply, particularly at many points over a large area. An alternative indirect method is examined using time-series measurements of atmospheric temperature (or any other convenient conserved field variable) at points on a spatial grid.System identification methodology is applied to analyze atmospheric temperature data obtained in such near-calm conditions during an experiment with a low-flying helicopter. A three-parameter numerical model of atmospheric advection has been identified in the temperature data, the advection parameters being an eddy diffusion coefficient and horizontal components of the wind velocity. It has been demonstrated by analysis of all the assumptions, and using simulated data, that in this case the standard least-square procedure can be applied to recover sensible parameter estimates, even though the model is of the error-in-variables type and parameters appear to change abruptly at certain moments of time (but by a reasonably small amount). The parameter estimates have been validated against independent data.     

Electromagnetic fields induced in the world's oceans and the spatial distribution of electrical conductivity functions

The results of numerical simulation of electromagnetic fields induced in the world's oceans by solar daily variations are discussed. Some examples of apparent resistivity curves simulated for continental and ocean regions are demonstrated.     

滇池水中铝的形态分布初探

采用铬天青S光度法对滇池水中的总铝和各主要形态铝进行分析，并利用简单易行的紫外吸收表征水中有机物污染程度和颗粒物含量，初步探讨了各因素的变化对铝形态分布的影响。     

Correction for distortions of magnetotelluric fields: Limits of validity of the static approach

Subsurface inhomogeneities can be classified in three categories depending on the comparison of their sizes against the effective skin depth and “adjustment distance”. These categories are geological noise, local and regional inhomogeneities. Due to its random nature, geological noise leads to uncontrollable distortions of the magnetotelluric field. Such methods as curve shifting, distortion tensor techniques, decomposition and spatial filtering can effectively be used to correct for static shift caused by geological noise. It is shown that the effects of local and regional subsurface inhomogeneities reduce to static shifts of MT-curves when rather rigid conditions are satisfied. The methods used to suppress the effect of geological noise have limited applicability to local and regional inhomogeneities, which can be accurately accounted for only by modelling.     

试论中西古典地理学思想渊源

地理环境、生产活动及哲学思想,是我国先秦时期和古希腊时期的古典地理学思想发轫的主要渊源。由于先秦和古希腊在地理环境,生产活动及哲学思想上的差异,因而双方古典地理学的发展,异多于同,各具特色。     

Seismicity and isostasy

Both a theoretical treatment and observed data show that the isostatic gravity field and the seismicity are closely related. The equation for harmonic loading shows that large deviations from isostatic equilibrium lead to large shear stresses in the crust. High seismic activity correlates well with large isostatic gravity anomalies and with large horizontal gradients of isostatic gravity anomalies. Studies of seismicity should consider the isostatic gravity field.     

Isomorphic sodium admixture in garnets formed at high pressures

Na₂O contents were determined by electron microprobe analysis in 124 garnets from diamonds, xenoliths of peridotites, eclogites from kimberlitic pipes and metamorphic complexes. Na₂O content ranges between 0.01 and 0.22% with the limit of detection at about 0.01%. In the garnets of diamond-bearing eclogites and orange garnets from diamonds a regular increase in the Na₂O content has been established, varying from 0.09 to 0.22, as compared to garnets from eclogites of metamorphic complexes (range 0.01 to 0.06). It is assumed that the increased Na₂O content in the garnets of eclogites is mainly connected with higher pressure, whereas isomorphism of sodium is connected with the initial stages of the transition from Si⁴ to Si⁶ in the garnet structure: CaAlNaSi.The study of the sodium content of garnets has shown that all the orange-coloured garnets from diamonds so far studied are related to eclogite assemblage. Determination of the Na₂O content of individual inclusions of chrome pyropes from diamonds permits a conclusion on the type of assemblage (with or without clinopyroxene). Proceeding from these data, the importance of garnet-olivine paragenesis within the stability field of diamond has been revealed.Some clear distinctions in the sodium content of the garnets from xenoliths of the kyanite eclogites from the Zagadochnaya pipe in Yakutia and the Roberts Victor mine in South Africa confirm the relation of these eclogites to different subfacies.A conclusion is drawn as to the possibility of utilizing the Na/Na+Ca distribution in the garnets and pyroxenes of eclogites of especially deep-seated origin as a pressure indicator and to the necessity for experimental testing of the dependence of the distribution of these elements in garnets and pyroxenes on pressure, presumably in the range of 30–100 kbars.     

On the height scale of magnetic fields above sunspots derived from RATAN-600 observations

Model calculations of the S-component are compared with observations of the RATAN-600 telescope at five discrete microwave frequencies referring to active region McMath No. 15974 on May 1, 1979. The spectral variations of source diameter, flux density, and degree of polarization are used to derive the height scale of the magnetic field in accordance with a magnetic dipole distribution under the assumption of advanced temperature and electron density distributions according to most recent EUV observations.