Fluoreszenz und Gelbstoff im Bottnischen und Finnischen Meerbusen

Zusammenfassung In der folgenden Arbeit wird der erstmalige Versuch unternommen, einen quantitativen Einblick in die gegenseitigen Beziehungen zweier im Meerwasser vorhandenen ausgesprochen organischen Stoffe in ihrer Abhängigkeit vom Salzgehalt zu gewinnen. Derartige Messungen waren bisher noch nicht möglich vor allem wegen der überaus geringen Konzentration, in der die organischen Stoffe im Meerwasser vorzukommen pflegen, sodann auch wegen der verhältnismäßig großen Abbaugeschwindigkeit, der diese Stoffe unter den natürlichen Bedingungen im Meere unterliegen. Bei den hier angestellten Untersuchungen handelt es sich um zwei verhältnismäßig stabile den Humusstoffen nahestehende Verbindungen, die sich einmal durch ihr Vermögen, im ultravioletten Licht zu fluoreszieren und zum anderen durch ihre gelbe Farbe auszeichnen. Als Untersuchungsgebiet wurden der Bottnische und Finnische Meerbusen ausgewählt, die an diesen Stoffen verhältnismäßig reich sind. Legt man vier Ausgangswässer zugrunde, so läßt sich die eigenartige Verteilung dieses Fluoreszenz- und Gelb-Stoffes in dem Untersuchungsgebiet zwangslos aus den gegenseitigen Mischungsvorgängen dieser Wässer deuten. Der Vorzug der neuartigen Methodik für zukünftige Messungen liegt in dreierlei. Erstens verspricht die Bestimmung eine tieferen Einblick in den bisher noch so ungeklärten Mechanismus der Humusbildung, ferner ermöglicht sie eine genauere Kontrolle des Aussüßungsvorganges in den Randmeergebieten als es bisher möglich war, und schließlich scheint sie berufen, bei weiterer Durchentwicklung der Methodik für die Aufklärung der chemisch-biologischen Grundvorgänge im Zusammenhang mit der Produktionsfrage des Meeres eine wichtige Lücke ausfüllen zu können.

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Fluorescence and contents of yellow substance in the Gulfs of Bothnia and Finland

Summary In the following paper it is tried for the first time to provide a quantitative insight into the relations between two clearly organic substances in the sea-water as depending on salinity. Measurings of this kind could not be made so far especially because the organic substances usually occur in sea-water in very low concentration, furthermore because they decay rather rapidly under the natural conditions prevailing in the sea. The investigations in question deal with two relatively stable compositions closely related to the ulmous substances which are characterized on the one hand by their capability of fluorescence in ultraviolet light and on the other hand by their yellow colour. The investigations are based on water-samples from the Gulfs of Bothnia and Finland, which are relatively abounding in these substances. Assuming four primary kinds of water, the peculiar distribution of these fluorescence and yellow substances in the investigated area can be explained without restriction by mixing processes of these waters. The advantages of the new method of investigation are: firstly that it may be expected to get a deeper insight into the genesis of humus which is only very little elucidated so far, furthermore it allows to control more exactly the process of freshening of the water in marginal seas, and finally, in case of further development it seems to be qualified to fill up a remarkable gap in the elucidation of the fundamental processes in biological chemistry in connection with the problem of marine production.

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Die Veröffentlichung der im wesentlichen bereits vor etwa zehn Jahren abgeschlossenen Arbeit ist durch den Krieg verzögert worden.     

A general method for calculating three-dimensional laminar and turbulent boundary layers on ship hulls

A general method for representing the flow properties in the three-dimensional boundary layers around ship hulls of arbitrary shape is described. It makes use of an efficient two-point finite-diffirence schem to solve the boundary-layer equations and includes an algebraic eddy-viscosity representaion of the Reynolds-stress ternsor. The numericzal method contains novel and desirable features and allows the calculation of flows in which the circumferential velocity component contains regions of flow reversal across the boundary layer. The inviscid pressure distribution is determined with the Douglas-Neumann method which, if necessary, can conveniently allow for the boundary-layer displacement surface. To allow its application to ships, and particularly to those with double-elliptic and flat-bottomed hulls, a non-orthogonal coordinate system has been developed and is shown to be economical, precise and comparatively easy to use. Present calculations relate to zero Froude number but they can be extended to include the effects of a water wave and local regions of flow separation which may stem from bulbous-bow geometries.     

Variability and trends in daily minimum and maximum temperatures and in the diurnal temperature range in Lithuania,Latvia and Estonia in 1951–2010

Spatial distribution and trends in mean and absolute maximum and minimum temperatures and in the diurnal temperature range were analysed at 47 stations in the eastern Baltic region (Lithuania, Latvia and Estonia) during 1951–2010. Dependence of the studied variables on geographical factors (latitude, the Baltic Sea, land elevation) is discussed. Statistically significant increasing trends in maximum and minimum temperatures were detected for March, April, July, August and annual values. At the majority of stations, the increase was detected also in February and May in case of maximum temperature and in January and May in case of minimum temperature. Warming was slightly higher in the northern part of the study area, i.e. in Estonia. Trends in the diurnal temperature range differ seasonally. The highest increasing trend revealed in April and, at some stations, also in May, July and August. Negative and mostly insignificant changes have occurred in January, February, March and June. The annual temperature range has not changed.     

Cooling of the Kärdla impact crater: I. The mineral paragenetic sequence observation

Abstract— The impact‐induced hydrothermal system in the well‐preserved, 4 km‐diameter Kärdla impact crater on Hiiumaa Island, western Estonia, was investigated by means of mineralogical, chemical, and stable C and O isotope studies. The mineralization paragenetic sequence, with gradually decreasing temperature, reveals at least three evolutionary stages in the development of the post‐impact hydrothermal system: 1) an early vapor‐dominated stage (>300 °C) with precipitation of submicroscopic adularia type K‐feldspar; 2) the main stage (300 to 150/100 °C) with the development of a two‐phase (vapor to liquid) zone leading to precipitation of chlorite/corrensite, (idiomorphic) euhedral K‐feldspar, and quartz; and 3) a late liquid‐dominated stage (<100 °C) with calcite I, dolomite, quartz, calcite II, chalcopyrite/pyrite, Fe‐oxyhydrate, and calcite III precipitation.     

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