Towards a multi-scale approach for an Earth observation-based assessment of natural resource exploitation in conflict regions

The exploitation of resources, if not properly managed, can lead to spoiling natural habitats as well as to threatening people’s health, livelihoods and security. The paper discusses a multi-scale Earth observation-based approach to provide independent information related to exploitation activities of natural resources for countries which are experiencing armed conflict. The analyses are based on medium to very high spatial resolution optical satellite data. Object-based image analysis is used for information extraction at these different scales. On a subnational level, conflict-related land cover changes as an indication of potential hot spots for exploitation activities are classified. The regional assessment provides information about potential activity areas of resource exploitation, whereas on a local scale, a site-specific assessment of exploitation areas is performed. The study demonstrates the potential of remote sensing for supporting the monitoring and documentation of natural resource exploitation in conflict regions.     

Impact of in-consistency between the climate model and its initial conditions on climate prediction

We investigated the influence of dynamical in-consistency of initial conditions on the predictive skill of decadal climate predictions. The investigation builds on the fully coupled global model “Coupled GCM for Earth Simulator” (CFES). In two separate experiments, the ocean component of the coupled model is full-field initialized with two different initial fields from either the same coupled model CFES or the GECCO2 Ocean Synthesis while the atmosphere is initialized from CFES in both cases. Differences between both experiments show that higher SST forecast skill is obtained when initializing with coupled data assimilation initial conditions (CIH) instead of those from GECCO2 (GIH), with the most significant difference in skill obtained over the tropical Pacific at lead year one. High predictive skill of SST over the tropical Pacific seen in CIH reflects the good reproduction of El Niño events at lead year one. In contrast, GIH produces additional erroneous El Niño events. The tropical Pacific skill differences between both runs can be rationalized in terms of the zonal momentum balance between the wind stress and pressure gradient force, which characterizes the upper equatorial Pacific. In GIH, the differences between the oceanic and atmospheric state at initial time leads to imbalance between the zonal wind stress and pressure gradient force over the equatorial Pacific, which leads to the additional pseudo El Niño events and explains reduced predictive skill. The balance can be reestablished if anomaly initialization strategy is applied with GECCO2 initial conditions and improved predictive skill in the tropical Pacific is observed at lead year one. However, initializing the coupled model with self-consistent initial conditions leads to the highest skill of climate prediction in the tropical Pacific by preserving the momentum balance between zonal wind stress and pressure gradient force along the equatorial Pacific.

     

Lateral dispersion of low-energy protons precipitated in the auroral zones

Through the use of a Monte Carlo type calculation, the lateral dispersion of a fine proton beam of given energy and pitch angle in an atmosphere of given exospheric temperature is investigated. It is found that this lateral dispersion may be estimated by using a simple analytical expression.     

Sunspot and stray light observations during the 1971, February 25 partial solar eclipse

Observations of a sunspot during and after a partial solar eclipse are described. The amount of scattered light confirms the existence of a spread function component with a half width of 10″. The observations also indicate the possibility of severely underestimating this component by aureole measurements. Umbral continuum intensities of 0.10 I _⊙ in the red spectral region were directly measured, the correction for scattered light amounts to 0.02 I _⊙. Intensities calculated with four umbral models are larger than the observed values, indicating this sunspot to be cooler by some 100 K. The wings of two strong Ca i lines are equally explained by the models of Henoux, Kneer, and Stellmacher/Wiehr. Yun's model can be ruled out because of too high a temperature.     

The variational equation of the three-body problem

Letx ₀ (t),x ₀ ⁴ be a homothetic solution of the planar three-body problem with total energyh, described in relative coordinates with respect to one body. It is shown that the variational equation of the problem atx ₀ (t) can be solved explicitly in terms of hypergeometric functions. This is done by using the scaled true anomaly of the one-dimensional Kepler motion as the independent variable.The classical theorems about hypergeometric functions allow a simple calculation of all the values needed in applications. By means of this theory the past of a homothetic triple close encounter may be described in a linearized approximation.Proceedings of the Sixth Conference on Mathematical Methods in Celestial Mechanics held at Oberwolfach (West Germany) from 14 to 19 August, 1978.     

The spectrum of the Cr star epsilon ursae majoris

Fourteen coudé spectrograms (eight with dispersion 12.4 Å mm^–1 and six 7 Å mm^–1) of the Cr star UMa (Ap) have been studied. The observations were made at the Haute Provence Observatory. The radial velocities of the various ions have been measured. The existence of Balmer progression in radial velocity is doubtful. The variability of some lines is in the opposite sense of K of Caii. Both a rough and a fine analysis have been made. The results of these analyses are compared and found to be in good agreement. The results of the fine analysis indicate a defect of Al, Si and Ca; Sc, Ti, Fe and Sr are normal, Mg and Ni are in slight excess. V, Cr and Mn are in excess by factors of 3, 12, 19; Y, Zr and Ba are in excess by factors of 9, 15, 30. Rare earths are in excess by factors ranging between 100–1000. These results are compared with the majority of the Cr–Eu–Sr stars.The observations have been made at the 152 cm coudé telescope of the Haute Provence Observatory.     

The nature of chemical bond of magnetite and consequences

Summary Types of chemical bonding in magnetite are discussed. Magnetite spinel lattice is characterized by tetrahedral covalent bonds and octahedral electrovalent bonds. The consequences for oxidation processes are studied in connection with hitherto existing experimental and theoretical results.

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Zusammenfassung Der Charakter der chemischen Bindung im Magnetit wird diskutiert. Für das Spinellgitter des Magnetits sind tetraedrische kovalente und oktaedrische elektrovalente Bindungen typisch. Die Auswirkungen dieses Bindungszustandes auf den Ablauf der Oxydationsvorgänge wird überprüft an Hand der bisher vorliegenden experimentellen und theoretischen Teilergebnisse.

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Dr. Dr. habil.F. Frölich, Dr.H. Stiller, Geomagnetic InstituteFotsdam, German Academy of Science at Berlin, Mitteilung Nr. 133.