Evaluation of Modeled Spatially and Temporarily Highly Resolved Emission Inventories of Photosmog Precursors for the City of Augsburg: The Experiment EVA and Its Major Results

Emission inventories of NO_x, CO, and individual volatile organic compounds (VOC), highly resolved in space and time, belong to the most important input parameters for chemistry and transport models (CTM) used for ozone prediction. Because of the decisive influence of the input quality on the outcome of CTM simulations, the quality of emission inventories has to be assessed. This paper presents an experimental evaluation of the highly resolved emission inventories for the city of Augsburg. The emissions of the city, determined in March and October 1998 using mass balance and tracer techniques, and derived from the measured receptor concentration ratios, were compared with emissions modeled from an emission inventory. The modeled CO emissions were in agreement with the measured ones within the combined experimental and model uncertainties. More detailed CO emission model simulations suggest that the tendency of calculated CO emissions being smaller than the measured ones may be due to higher traffic activity in Augsburg. Modeled NO_x emissions were in agreement with the measured ones within the combined experimental and model uncertainties. Large deviations between modeled and measured values have been found for some individual NMHC compounds. The measured NMHC emission fingerprints were dominated by mobile sources. Substantial model predicted NMHC emissions from the solvent use could not be detected by measurements suggesting that they may not be correctly represented by the emission model.     

The dependence of albedo on solar elevation

Summary Highest values of measured sky polarization 90° from the sun as function of solar elevation have been compared with theoretical data of the Rayleigh atmosphere for different albedo. The conclusion is that the effective albedo of the earth surface increasing from 0.1 at 40° solar elevation to about 0.25 at 10° elevation, whereas reflection according Lamberts cosine law would result in an albedo independent of solar elevation. This result could be generally confirmed by laboratory measurements of albedo of surfaces like grass, soil, sand, etc.

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Zusammenfassung Höchste gemessene Werte der Himmelslichtpolarisation in 90° Abstand von der Sonne in Abhängigkeit von der Sonnenhöhe wurden mit theoretischen Werten der Polarisation einer Rayleigh-Atmosphäre bei verschiedener Albedo verglichen. Es ergibt sich daraus, dass die effektive Albedo der Erdoberfläche von etwa 0.1 bei 40° Sonnenhöhe auf 0.25 bei 10° Sonnenhöhe ansteigt, während Reflektion nach dem Lambertschen cos-Gesetz eine Albedo bedingen würde, die unabhängig von der Sonnenhöhe ist. Dieses Ergebnis konnte durch Labormessungen der Albedo in Abhängigkeit vom Einfallswinkel für Oberflächen aus Gras, Boden, Sand und anderem im wesentlichen bestätigt werden.

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Publication No. 82.     

Iron in silicate glasses of granitic composition: a Mössbauer spectroscopic study

⁵⁷Fe Mössbauer spectra of natural glasses (pumices and obsidians) and of synthetic glasses of granitic composition have been analyzed. — Ferric iron is found in tetrahedral coordination if enough M⁺-cations are available to balance the charge of both M⁺Fe³⁺O₂ and M⁺AlO₂ complexes. In other compositions the ratio of tetrahedrally to octahedrally coordinated Fe³⁺ depends on the ratio of mono-to divalent cations. — Ferrous iron occurs in two distinctly different octahedral sites. The existence of these sites can be attributed to different anionic units adjacent to Fe²⁺. The degree of polymerization of these units is reflected in the quadrupole splitting. The anionic units adjacent to Fe²⁺ are depolymerized for increasing mean Z/r ² of the network modifiers, which do not stabilize M³⁺ in the tetrahedra by local charge balance. — Increasing pressure diminishes the geometric differences between these types of ferrous iron-oxygen-octahedra, which gives rise to a more even distribution of Fe²⁺ among these sites and thereby to an ordering in the network of melts.     

The transformation of amorphous silica to crystalline silica under hydrothermal conditions

Hydrothermal syntheses were made mainly in the binary system SiO₂-H₂O in a temperature range between 300 ° C and 500 ° C and pressures from 0.2 kbar up to 4.0 kbar with various starting materials. In this way the transformation behavior of different amorphous silicas via cristobalite and keatite to quartz were observed. This behavior depends mainly on the parameters: pressure, temperature, run duration and state of the starting material. Four reaction paths have been observed: in most experiments the complete reaction sequence “amorphous silica→cristobalite→keatite→quartz” took place. Less often the reactions: “amorphous silica→cristobalite→quartz” and: “amorphous silica→keatite→quarts” were observed. Very few samples were found with a direct transition of amorphous silica into quartz at high pressures. A kinetic model is given in form of a pressure-temperature-time diagram of the system SiO₂-H₂O under hydrothermal conditions.     

Über einen Keuperton von Zaisersweiher bei Maulbronn

Zusammenfassung Durch röntgenographisehe und differentialthermoanalytische Untersuchungen wurde in einem roten Keuperton (km 3) von Zaisersweiher bei Maulbronn ein quellfähiges chloritisches Mineral (Corrensit) als Hauptbestandteil gefunden, das sick durch doppelten Basisabstand (28 Å) auszeichnet. Daneben treten Illit (Glimmer) und Quarz auf. Nebengemengteile sind Hämatit und Feldspat.Herrn Professor Dr.Carl W. Correns zum 60. Geburtstag gewidmet.     

Raman-spectroscopy and X-ray diffractometer studies of experimentally produced diaplectic feldspar glass

Raman vibrational spectra and X-ray diffractometer scans were obtained from experimentally shocked samples of oligoclase (An₁₉) and andesine (An₄₉). Some 11 oligoclase and 15 andesine targets were shocked between 24 and 40 GPa to address the transition from crystalline to diaplectic states and to explore differences in the structural state of diaplectic feldspar glasses (maskelynite) as a function of peak shock stress. Thy symmetrical VS (T-O-T) (T=Si or Al) stretch bands are the most persistent. They disappear, however, in the noise of an unusually strong luminescent spectrum at > 32 GPa in the oligoclase and at > 30 GPa in the andesine; i.e., at pressures where transition to diaplectic glass is complete. The Raman investigations yield a maskelynite structure that is probably one of a multitude of very small domains with some order, but with a large range of local properties on the scale of small domains, either in heterogeneous size-distribution of domains or in their detailed order, if not both. This results in a very large number of Raman photon-phonon frequencies unlike glasses derived from quenched melts. Our study corroborates conclusions by others, that diaplectic glasses may be the quench products of very dense, disordered phases that exist during shock compression and that subsequently relax to these unusually dense glasses that are only known from shock processes. An origin by relaxation of highly ordered, genuine high pressure polymorphs possessing the structure of hollandite is unlikely, as no evidence for any six-fold Si-coordination was found. Detailed luminescent emission spectra were taken of the oligoclase samples and they show disappearance of the IR band and a strengthening of the green band (the blue band could not be detected with a primary radiation of wavelength 448 nm). This supports previous views that the disappearance of IR emission is most likely caused by shock-induced changes of the crystal field near Fe³⁺ sites, rather than due to quenching by Fe²⁺. The X-ray studies were primarily intended to explore whether differences in structural states of maskelynite occur on sufficiently large scales to be detected by standard diffractometry methods. This is not the case. X-ray diffractometer patterns are grossly similar, if not identical, in samples shocked between 30 and 40 GPa and may not be used to fine-tune the shock histories of naturally produced diaplectic glasses.     

Über das Verhalten der Skelette planktischer Kieselalgen im geschichteten Tiefenschlamm des Zürich- und Baldeggersees

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