Tailoring spatial reference in early warning systems to administrative units

This paper presents a novel approach for early warning systems to transform the spatial reference of dispersion models into addressable administrative units enabling an intelligible warning message reception and spatial awareness. The spatial reference along the entire information chain from sensor measurements via dispersion model to warning dissemination is discussed. Core concept behind this approach is the application of the Egenhofer-Model for analysis of binary topologic relations. It is used to identify topologic relations between dispersion model forecasts and administrative units. The result set of intersection matrices defines the relations that are counted for area classification with hazard specific parameters. Following the design for a generic and hazard-independent web service based on Open Geospatial Consortium (OGC) standards is presented in combination with results of the reference implementation.     

Quantificational reductionism as a risk in geography and cartography

A reductionistic concept is being pursued in the 125 000 geomorphological mapping of the Federal Republic of Germany. Complex landscape elements with a base length greater than 100 m are broken down into partial elements and re-interpreted in terms of quantificational or abstractly defined, theoretically neutral map symbols. The genetic aspect is expressed by areal colouring. In this way it aims to achieve an interdisciplinary utilization of such information. This reduction has proved to be too drastic insofar as it gives rise to irretrievable loss of information. The claim that use-oriented, ecologically relevant information would be derivable from the GMM-25 has not been substantiated. As ecologically justifiable evaluation must also consider as its most fundamental indicators the quality and distribution of biotopes. These are not even rudimentarily included in the GMM-25. The uncontextualized blending of information units which only make sense in heterogeneous contexts to produce a single map is antithetical to the principle of subject related selection of relevant characteristics and prevents comprehension of the systematic relationships.The underlying concept of the GMM-25, derived from an uncritical incorporation of physico-mathematical total predictability principles, leads to an irreversible renunciation of the necessarily complex constituents of a high geomorphological level of integration.     

Emplacement of the Ardara pluton (Ireland): new constraints from magnetic fabrics, rock fabrics and age dating

The Ardara pluton as part of the Donegal batholith was intruded into Neoproterozoic metasediments and metadolerites at mid-crustal levels. The emplacement mechanism of the Ardara granite is very controversial, and mechanisms ranging from diapirism, ballooning and stoping followed by nested diapirism have been proposed. Magnetic fabrics, rock fabrics and K/Ar dating of micas are used here to constrain the emplacement history. The compositional zoning of the Ardara pluton is clearly reflected in the different bulk magnetic susceptibilities between the outer quartz monzodiorite and the central granodiorite, whereas the intervening tonalite is of intermediate nature. The magnetic carriers are characterized by the anisotropy of the magnetic susceptibility (AMS), thermomagnetic measurements and through high field analyses (HFA). The separation of the ferrimagnetic and paramagnetic contributions revealed that biotite and magnetite control the AMS in the quartz monzodiorite. Both minerals are oriented in such a way that their summed contribution is constructive and originates from the shape fabric of magnetite and the texture of biotite. Biotite is responsible mainly for the AMS in the tonalite and granodiorite. The magnetic foliation can be directly related to the macroscopic foliation and also to the D4 structures in the country rocks. The foliation is consistent with the geometry of the roughly circular shape and has a mostly steep to vertical dip. Towards the central granodiorite the magnetic foliation dies out, although plagioclase texture measurements indicate a weak magmatic shape fabric. With the exception of the tail, the K_max axes (magnetic lineation) vary from steeply to gently plunging. The so-called lineation factor is approximately 1.01 and therefore points to a less significant axial symmetry. These observations coincide with strain estimates on mafic enclaves that show a very consistent pattern of K ∼0 flattening strain. Texture analyses of biotite and quartz additionally support the observations made by the strain analyses and the magnetic fabric data. Microstructural investigations give evidence that the fabrics are associated with the emplacement over a range of temperatures from truly magmatic to high-temperature solid-state conditions. The age of the intrusion is still under discussion, but a new cooling age was determined by K/Ar dating of biotite at 403.7±8 Ma corresponding to a temperature range between 450 and 300°C. For a mylonite along the southern contact between the Ardara pluton and the country rock a K/Ar muscovite age of 378.8±7 Ma indicates a minimum age for the shear zone when the Ardara pluton must have already been cooled down below 350±50°C. Received: 28 January 1999 / Accepted: 28 December 1999     

Anomalous phosphorus episodes during Callovian-Oxfordian times in the Kachchh Basin,western India: Implications for palaeoclimate,productivity, and weathering

The Upper Callovian-Oxfordian strata of the Kachchh Basin, western India, record three positive excursions of phosphorus. They have been documented in three sections of the Chari Formation from different parts of the basin. Corroboration of field and petrographic data with trends of major and trace elemental data and elemental ratios of the strata revealed that these excursions were coeval with reduced chemical weathering in the source area and significant reduction of siliciclastic influx to the depositional sites. The study also revealed the intrabasinal source of P, and minor sea-level fluctuations and resultant episodic sediment recycling as the causative factors. Considering the geographic locations of the three sections, the phosphorus anomalies seem to be controlled by a regional and/or basin-scale process, if not linked with global signals. Temporal resolution of these anomalies suggests that the processes were episodic and related to short term climate/relative sea-level cycles, the durations of which could be unraveled with high-resolution biostratigraphic data.     

Observed monthly precipitation trends in China 1951–2002

Summary Monthly precipitation trends of 160 stations in China from 1951–2002 have been analysed and interpolated. The Mann-Kendall trend test was applied to examine the monthly precipitation data. Significant positive and negative trends at the 90, 95, and 99 percent confidence levels were detected for numerous stations. The number, distribution, and direction of the trends varied from month to month.The detected trends were spatially interpolated by applying the Inverse Distance Weighted (IDW) interpolation method. The spatial presentation of the detected precipitation trends gives a better understanding of climatic changes or variations in China during the last 50 years. This is especially the case for highlighting the spatial structure of precipitation trends.A clustering of trends is observed in certain months, including distinct trend belts especially in east and north-east China. Nevertheless, positive as well as negative monthly trends can be noted simultaneously in different areas. The spatial interpolation of precipitation trend analysis results is a useful approach to give further understanding of the regional pattern of precipitation trends in China.     

Gas phase reactions of alkyl nitrates with hydroxyl radicals under tropospheric conditions in comparison with photolysis

Rate constants for the reaction of OH radicals with some branched alkyl nitrates have been measured applying a competitive technique. Methyl nitrite photolysis in synthetic air was used as OH radical source at 295±2 K and 1000 mbar total pressure. Using a rate constant of 2.53×10^-12 cm³ s^-1 for the reaction of OH radicals with n-butane as reference, the following rate constants were obtained (units: 10^-12 cm³ s^-1): isopropyl nitrate, 0.59±0.22; isobutyl nitrate, 1.63±0.20; 3-methyl-2-butyl nitrate, 1.95±0.15; 2-methyl-1-butyl nitrate, 2.50±0.15; 3-methyl-1-butyl nitrate, 2.55±0.35. These values have been combined with the literature data to recalculate the substituent factors F(X) for the different nitrate groups which can be used to predict OH rate constants for organic nitrates for which experimental data are not available.Preliminary measurements of the photolysis frequency of isopropyl nitrate have shown that for this nitrate as a model substance, OH reactions and direct photolysis are of equal importance under tropospheric conditions.     

The energy balance experiment EBEX-2000. Part II: Intercomparison of eddy-covariance sensors and post-field data processing methods

The eddy-covariance method is the primary way of measuring turbulent fluxes directly. Many investigators have found that these flux measurements often do not satisfy a fundamental criterion—closure of the surface energy balance. This study investigates to what extent the eddy-covariance measurement technology can be made responsible for this deficiency, in particular the effects of instrumentation or of the post-field data processing. Therefore, current eddy-covariance sensors and several post-field data processing methods were compared. The differences in methodology resulted in deviations of 10% for the sensible heat flux and of 15% for the latent heat flux for an averaging time of 30 min. These disparities were mostly due to different sensor separation corrections and a linear detrending of the data. The impact of different instrumentation on the resulting heat flux estimates was significantly higher. Large deviations from the reference system of up to 50% were found for some sensor combinations. However, very good measurement quality was found for a CSAT3 sonic together with a KH20 krypton hygrometer and also for a UW sonic together with a KH20. If these systems are well calibrated and maintained, an accuracy of better than 5% can be achieved for 30-min values of sensible and latent heat flux measurements. The results from the sonic anemometers Gill Solent-HS, ATI-K, Metek USA-1, and R.M. Young 81000 showed more or less larger deviations from the reference system. The LI-COR LI-7500 open-path H₂O/CO₂ gas analyser in the test was one of the first serial numbers of this sensor type and had technical problems regarding direct solar radiation sensitivity and signal delay. These problems are known by the manufacturer and improvements of the sensor have since been made. The National Center for Atmospheric Research is supported by the National Science Foundation.     

A multi-proxy approach for revealing recent climatic changes in the Russian Altai

For the first time we present a multi-proxy data set for the Russian Altai, consisting of Siberian larch tree-ring width (TRW), latewood density (MXD), δ¹³C and δ¹⁸O in cellulose chronologies obtained for the period 1779–2007 and cell wall thickness (CWT) for 1900–2008. All of these parameters agree well between each other in the high-frequency variability, while the low-frequency climate information shows systematic differences. The correlation analysis with temperature and precipitation data from the closest weather station and gridded data revealed that annual TRW, MXD, CWT, and δ¹³C data contain a strong summer temperature signal, while δ¹⁸O in cellulose represents a mixed summer and winter temperature and precipitation signal. The temperature and precipitation reconstructions from the Belukha ice core and Teletskoe lake sediments were used to investigate the correspondence of different independent proxies. Low frequency patterns in TRW and δ¹³C chronologies are consistent with temperature reconstructions from nearby Belukha ice core and Teletskoe lake sediments showing a pronounced warming trend in the last century. Their combination could be used for the regional temperature reconstruction. The long-term δ¹⁸O trend agrees with the precipitation reconstruction from the Teletskoe lake sediment indicating more humid conditions during the twentieth century. Therefore, these two proxies could be combined for the precipitation reconstruction.