Solar and meteoritic abundance of silicon

Recent lifetime measurements on excited electronic states of neutral silicon (Beckeret al., Phys. Lett. In press, 1980) lead to a reassessment of widely used experimental transition probabilities Garz, Astron. Astrophys., 26, 471–477, 1973 of Si I lines. This translates into a 25% downward revision of the Si abundance determined from the solar spectrum.A solar atomic ratio, Si/Ca = 15.5 is inferred. This value coincides with that found in carbonaceous chondrites, but contrasts with ordinary and enstatite chondrites.     

Vibrations of the elastic half-space due to vertical surface loads

The displacements of the surface of the homogeneous elastic half-space subjected to a vertical concentrated load acting at the surface are calculated. The solution is shown to approach Lamb's simple formula for the far-field. The solution for the concentrated load can be used to calculate displacements due to distributed loads with high accuracy and economically. The results are applied to define the regions ‘near-field’ and ‘far-field’. Some near-field phenomena are described.     

Nitratbestimmung im Trinkwasser nach dem flow-stream-Prinzip mittels einer ionensensitiven Meßzelle

Beschrieben wird eine automatisierte Methode zur Bestimmung des Nitrats in Trinkwässern mittels einer ionensensitiven Meßzelle. Mit dem vorgestellten Verfahren können 80 Proben pro Stunde auf ihren Nitratgehalt im Konzentrationsbereich von 1,5 · 10^–5 bis 1,0 · 10^–3 Mol/l analysiert werden. Der Aufbau der Automateneinheit, der Durchflußmeßzelle, sowie das Meßprinzip weiden erläutert.     

A cross section through the central-Pyrenees

Summary A structural analysis of the Pyrenees contains successively from young to old the Miocene morphogenic uplift, a Pyreneic and a Laramide folding phase each preceded by basin formation on the flanks of the central zone, and a rather complicated Hercynian folding period accompanied by magmatic hases. This Hercynian phase starts with a Devonian geosyncline and its folding movement is directed towards the centre, and proceeds later from the centre outwards. In the Hercynian structure one can discern a central anticlinorium and two or three anticlinoria in the flank.Summary of a lecture given in Köln on the 27^th Jan. 1956.     

Intercomparison of Tropospheric OH Measurements by Different Laser Techniques during the POPCORN Campaign 1994

In-situ OH measurements by laser-induced fluorescence (LIF) spectroscopy and folded long-path differential optical absorption spectroscopy (DOAS) were carried out in a rural environment in North-East Germany as part of the field experiment POPCORN in August 1994. The large set of OH data obtained allowed an intercomparison of both techniques based on relative diurnal profiles and simultaneously measured absolute concentrations. Most of the time the two OH instruments encountered the same air and agreed well in the measured relative diurnal variations. Only on a few occasions the measurements significantly disagreed due to a perturbation of the DOAS measurements by a local OH source in the north-western wind sector. Excluding data from this wind direction, the statistical analysis of 137 data pairs yields a correlation coefficient of r = 0.90 and a weighted linear fit with a slope of 1.09 ± 0.12. The correlations are carefully analyzed. The comparison of both instruments is discussed in the light of newly published effective absorption cross-sections for H2O and O2 that affect the calibration of LIF.     

Numerical Simulation of the Sensitivity of Summer Monsoon Circulation and Rainfall over India to Land Surface Processes

—The influence of soil moisture and vegetation variation on simulation of monsoon circulation and rainfall is investigated. For this purpose a simple land surface parameterization scheme is incorporated in a three-dimensional regional high resolution nested grid atmospheric model. Based on the land surface parameterization scheme, latent heat and sensible heat fluxes are explicitly estimated over the entire domain of the model. Two sensitivity studies are conducted; one with bare dry soil conditions (no latent heat flux from land surface) and the other with realistic representation of the land surface parameters such as soil moisture, vegetation cover and landuse patterns in the numerical simulation. The sensitivity of main monsoon features such as Somali jet, monsoon trough and tropical easterly jet to land surface processes are discussed.¶Results suggest the necessity of including a detailed land surface parameterization in the realistic short-range weather numerical predictions. An enhanced short-range prediction of hydrological cycle including precipitation was produced by the model, with land surface processes parameterized. This parameterization appears to simulate all the main circulation features associated with the summer monsoon in a realistic manner.