Improving aircraft-derived temperature observations using data assimilation

Meteorological observations are very important for weather forecasting; one potential source of observations is commercial aircraft. Commercial aircraft transmit Mode Selective Enhanced Surveillance (Mode-S) reports, which include data about the aircraft’s ground speed and magnetic heading, but the reports do not include temperature readings. Instead, the Mach number and airspeed can be used to derive the temperature. However, to transmit the Mode-S report the precision in the Mach number and airspeed is reduced from 16 bits to 10 bits. This reduction in precision creates errors in the Mach number and airspeed, which in turn translate to errors between 4–7 K and 3–5 K respectively, in the derived temperature. These large errors may limit the use of these observations for weather forecasting. This paper investigates if optimal interpolation, a type of data assimilation, can be used to combine aircraft data with atmospheric model data to provide a better estimate of the temperature-derived observations. We find that optimal interpolation can reduce the standard deviation of the derived temperature observations to 1.12 K; however, this is too large to be used with numerical weather prediction where a standard deviation of 1.0K is required

Pinsker estimators for local helioseismology

A major goal of helioseismology is the three-dimensional reconstruction of the three velocity components of convective flows in the solar interior from sets of wave travel-time measurements. For small amplitude flows, the forward problem is described in good approximation by a large system of convolution equations. The input observations are highly noisy random vectors with a known dense covariance matrix. This leads to a large statistical linear inverse problem. Whereas for deterministic linear inverse problems several computationally efficient minimax optimal regularization methods exist, only one minimax-optimal linear estimator exists for statistical linear inverse problems: the Pinsker estimator. However, it is often computationally inefficient because it requires a singular value decomposition of the forward operator or it is not applicable because of an unknown noise covariance matrix, so it is rarely used for real-world problems. These limitations do not apply in helioseismology. We present a simplified proof of the optimality properties of the Pinsker estimator and show that it yields significantly better reconstructions than traditional inversion methods used in helioseismology, i.e.\ Regularized Least Squares (Tikhonov regularization) and SOLA (approximate inverse) methods. Moreover, we discuss the incorporation of the mass conservation constraint in the Pinsker scheme using staggered grids. With this improvement we can reconstruct not only horizontal, but also vertical velocity components that are much smaller in amplitude

Der Begriff Sport im deutschen und im europäischen Recht

Die Arbeit unternimmt es, den Begriff Sport für die Rechtswissenschaft zu definieren. Sie geht aus von einer allgemeinen Analyse juristischer und außerjuristischer Begriffe und Definitionen. Auf dieser Grundlage faßt sie Sport zunächst als allgemeinsprachlichen Begriff auf. Der Ausdruck "Sport" erweist sich danach als mehrdeutig, indem er einerseits bestimmte körperliche Betätigungen ("Körpersport"), andererseits bestimmte Arten von Wettkämpfen ("Wettkampfsport") bezeichnet. Die Arbeit untersucht sodann, ob sich dieses allgemeinsprachliche Sportverständnis auch für die juristische Fachsprache eignet. Das hängt davon ab, ob es den einschlägigen Bestimmungen des deutschen und europäischen Rechts angemessen ist. Im Ergebnis bejaht der Verfasser diese Frage

Emission of monoterpenes from European beech (<i>Fagus</i><i> sylvatica</i> L.) as a function of light and temperature

International audienceUsing a dynamic branch enclosure technique European beech (Fagus sylvatica L.) was characterised as a strong emitter of monoterpenes, with sabinene being the predominant compound released. Since monoterpene emission was demonstrated to be a function of light and temperature, application of light and temperature dependent algorithms resulted in reasonable agreement with the measured data. Furthermore, during high temperature periods the depression of net CO2 exchange during midday (midday depression) was accompanied by a depression of monoterpene emission on one occasion. The species dependent standard emission factor and the light and temperature regulated release of monoterpenes is of crucial importance for European VOC emissions. All measurements were performed within the framework of the ECHO project (Emission and CHemical transformation of biogenic volatile Organic compounds) during two intensive field campaigns in the summers of 2002 and 2003

Nachnutzung der gemeinsamen JOIN2^2 –Repository-Infrastruktur für den KDSF-Objektbereich Publikation?

Im Rahmen des JOIN2-Projekts haben Bibliotheks- & Dokumentationseinheiten (Deutsches Elektronensynchrotron DESY Hamburg/Zeuten, Deutsches Krebsforschungszentrum DKFZ Heidelberg, Forschungszentrum Jülich, GSI Helmholtzzentrum für Schwerionenforschung Darmstadt, Maier-Leibnitz-Zentrum Garching, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen, KIT Institut für experimentelle Kernphysik Karlsruhe) eine gemeinsame Repository-Infrastruktur für ihre Wissenschaftler und Wissenschaftlerinnen geschaffen. Das Poster dokumentiert Überlegungen, welche Anforderungen des Kerndatensatzes Forschung im Objektbereich abgebildet werden können, wo Probleme und fehlende Normierungen in der Praxis auftauchen könnten und vor allem, an welchen Stellen Kompromisse in Hinblick auf die JOIN2-Serviceorientierung für den Wissenschaftsbereich eingegangen werden müssen.Schlagwörter: Repositorium; VeröffentlichungsdatenbankSchwerpunktbereich: Identifikatoren & Anbindung von Drittsystemen, z.B. von Repositorie

Significant light and temperature dependent monoterpene emissions from European beech (fagus sylvatiga L.) and their potential impact on the European VOC budget

By using a dynamic branch enclosure system the emission of monoterpenes from European beech (Fagus sylvatica L.) was investigated during two consecutive summer vegetation periods in the years of 2002 and 2003 in Germany. All measurements were performed under field conditions within the framework of the ECHO project (Emission and Chemical Transformation of Biogenic Volatile Organic Compounds, AFO 2000). European beech was characterized as a substantial emitter of monoterpenes, with sabinene being the predominant compound released. The monoterpene emission from European beech was shown to be a function of light and temperature and agreed well to emission algorithms that consider a light and temperature dependent release of volatile organics. Standard emission factors that were measured from these sunlit leaves of European beech ranged up to 4–13 µg g-1 h-1 (normalized to 1000 µmol m-2 s-1, 30°C) in the years of 2003 and 2002, respectively. The nighttime emission of monoterpene compounds was negligible. Also the artificial darkening of the sunlit branch during daylight conditions led to an immediate cessation of monoterpene emission. European beech is the dominating deciduous tree species in Europe. To demonstrate the effect of an updated monoterpene emission factor for European beech in combination with the consideration of a light and temperature dependent monoterpene emission, we applied a species based model simulation on a European scale. With respect to conventional estimates of the European volatile organic compound budget, the latter simulation resulted in relative increases of 16% by taking solely this tree species into account. On local scales these increases exceeded even more than 100% depending on the respective vegetation area coverage of European beec