Ergebnisse neuer geologischer Forschung im Tian-Schan

Ohne Zusammenfassung     

Meereskundlich-chemische Untersuchungen mit Hilfe des Pulfrich-Photometers von Zeiss

Zusammenfassung Die bisherigen Methoden zur Bestimmung des Chlorophylls im Meerwasser benötigen zu ihrer Durchführung Wassermengen von einem bis zu einigen Litern. Sie sind infolgedessen zur Ausfühung serienmäßiger ozeanischer Messungen noch nicht voll geeignet. Durch Ausnutzung der intensiven Rotfluoreszenz des Chlorophylls und Benutzung kleinerer und engerer Kolorimeterröhren läßt es sich ermöglichen, den Wasserbedarf bis auf 100 ccm und weniger je Probe herabzudrücken und somit diesen Mangel zu beheben. Die für diesen Zweck geschaffene gleiche Arbeitsapparatur ermöglicht weiterhin, im Anschluß an die Chlorophyllbestimmung ohne wesentlich erhöhte Arbeitsbelastung die Bestimmung der Eigenfluoreszenz gleichfalls auf dem Wege der Mikromethodik an nur 1 ccm Meerwasser durchzuführen.

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Investigations in chemical oceanography carried out with the aid of the Pulfrich photometer

Summary The old method of determining the chlorophyll content of sea water required a comparatively great quantity of sea water (one or severel litres) and, hence, was not suitable in case of serial measurements. The utilization of the intensive red fluorescence of chlorophyll and the use of small and narrow colorimeter tubes render it possible to minimize the required quantity of water to 100 ccm and less per sample. The apparatus which was especially constructed for this purpose being fit for the determination of both the chlorophyll content and the proper fluorescence, the latter can be easily determined immediately after the determination of the chlorophyll content by means of the micro-method from only 1 ccm of sea water.

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Investigations chimiques dans le domaine océanographique à l'aide du photomètre de PulfrichVII^e communication. Les micro déterminations de la teneur en chlorophylle et de la fluorescence propre de l'eau de mer

Résumé La quantité minimale nécessaire pour déterminer la teneur en chlorophylle selon la méthode en usage jusqu' à présent se montait d'un à plusieurs litres; à cause de cela cette méthode n'était pas convenable pour des mensurations en séries. En se servant de l'intensive fluorescence rouge de la chlorophylle et en employant un petit tube étroit à colorimètre il est possible de limiter la quantité d'eau à 100 ccm et moins par échantillon. En outre, on peut se servir du même appareil pour déterminer la fluorescence propre selon la nouvelle méthode. Pour cette détermination qui peut être effectué sans peine immédiatement après celle de la chlorophylle on a besoin de seulement 1 ccm d'eau de mer.

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Die sechs vorhergehenden Mitteilungen sind in den Annalen der Hydrographie und maritimen Meteorologie erschienen, und zwar I:59, 1931, 313; II:61, 1933, 124; III:62, 1934, 65; IV:63, 1935, 58: V:63, 1935, 195; VI:65, 1937, 276.     

Die wirkliche Solarkonstante

Zusammenfassung Die Solarkonstante 2.4 wird begründet.

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Summary The true solar constant 2.4 is proved.

     

Increasing levels and biomagnification of persistent organic pollutants (POPs) in Antarctic biota

Representatives of the Antarctic food web (krill, cephalopod, fish, penguin, seal) of the area around Elephant Island and from the Weddell Sea were analysed for the most recalcitrant organochlorine compounds. Due to sorption of the compounds to sinking particles and accumulation in sediments, two benthic fish species (Gobionotothen gibberifrons, Chaenocephalus aceratus) feeding on benthos invertebrates and fish reflected significantly increasing concentrations within a decade (1987-1996), while a benthopelagic species (Champsocephalus gunnari) feeding on krill did not. In the pelagic food chain, lipid normalised concentrations of all compounds increased from Antarctic krill to fish proving that biomagnification of highly lipophilic pollutants (log octanol-water partition coefficient>5) occurs in water-breathing animals. As top predators Weddell and southern elephant seals (Leptonychotes weddellii, Mirounga leonina) biomagnified the persistent organic pollutants relative to krill 30-160 fold with the exception of hexachlorobenzene, the levels of which were lower than in fish indicating its intense specific elimination.     

Calibration of a Land Subsidence Model Using InSAR Data via the Ensemble Kalman Filter

The application of interferometric synthetic aperture radar (InSAR) has been increasingly used to improve capabilities to model land subsidence in hydrogeologic studies. A number of investigations over the last decade show how spatially detailed time‐lapse images of ground displacements could be utilized to advance our understanding for better predictions. In this work, we use simulated land subsidences as observed measurements, mimicking InSAR data to inversely infer inelastic specific storage in a stochastic framework. The inelastic specific storage is assumed as a random variable and modeled using a geostatistical method such that the detailed variations in space could be represented and also that the uncertainties of both characterization of specific storage and prediction of land subsidence can be assessed. The ensemble Kalman filter (EnKF), a real‐time data assimilation algorithm, is used to inversely calibrate a land subsidence model by matching simulated subsidences with InSAR data. The performance of the EnKF is demonstrated in a synthetic example in which simulated surface deformations using a reference field are assumed as InSAR data for inverse modeling. The results indicate: (1) the EnKF can be used successfully to calibrate a land subsidence model with InSAR data; the estimation of inelastic specific storage is improved, and uncertainty of prediction is reduced, when all the data are accounted for; and (2) if the same ensemble is used to estimate Kalman gain, the analysis errors could cause filter divergence; thus, it is essential to include localization in the EnKF for InSAR data assimilation.     

Optimized formulas for the gravitational field of a tesseroid

Various tasks in geodesy, geophysics, and related geosciences require precise information on the impact of mass distributions on gravity field-related quantities, such as the gravitational potential and its partial derivatives. Using forward modeling based on Newton’s integral, mass distributions are generally decomposed into regular elementary bodies. In classical approaches, prisms or point mass approximations are mostly utilized. Considering the effect of the sphericity of the Earth, alternative mass modeling methods based on tesseroid bodies (spherical prisms) should be taken into account, particularly in regional and global applications. Expressions for the gravitational field of a point mass are relatively simple when formulated in Cartesian coordinates. In the case of integrating over a tesseroid volume bounded by geocentric spherical coordinates, it will be shown that it is also beneficial to represent the integral kernel in terms of Cartesian coordinates. This considerably simplifies the determination of the tesseroid’s potential derivatives in comparison with previously published methodologies that make use of integral kernels expressed in spherical coordinates. Based on this idea, optimized formulas for the gravitational potential of a homogeneous tesseroid and its derivatives up to second-order are elaborated in this paper. These new formulas do not suffer from the polar singularity of the spherical coordinate system and can, therefore, be evaluated for any position on the globe. Since integrals over tesseroid volumes cannot be solved analytically, the numerical evaluation is achieved by means of expanding the integral kernel in a Taylor series with fourth-order error in the spatial coordinates of the integration point. As the structure of the Cartesian integral kernel is substantially simplified, Taylor coefficients can be represented in a compact and computationally attractive form. Thus, the use of the optimized tesseroid formulas particularly benefits from a significant decrease in computation time by about 45 % compared to previously used algorithms. In order to show the computational efficiency and to validate the mathematical derivations, the new tesseroid formulas are applied to two realistic numerical experiments and are compared to previously published tesseroid methods and the conventional prism approach.