Improvement and Sensitivity Analysis of Thermal Thin-Ice Thickness Retrievals

Considering the sea ice decline in the Arctic during the last decades, polynyas are of high research interest since these features are core areas of new ice formation. The determination of ice formation requires accurate retrieval of polynya area and thin-ice thickness (TIT) distribution within the polynya. We use an established energy balance model to derive TITs with MODIS ice surface temperatures $(T_{s})$ and NCEP/DOE Reanalysis II in the Laptev Sea for two winter seasons. Improvements of the algorithm mainly concern the implementation of an iterative approach to calculate the atmospheric flux components taking the atmospheric stratification into account. Furthermore, a sensitivity study is performed to analyze the errors of the ice thickness. The results are the following: 1) 2-m air temperatures $(T_{a})$ and $T_{s}$ have the highest impact on the retrieved ice thickness; 2) an overestimation of $T_{a}$ yields smaller ice thickness errors as an underestimation of $T_{a}$; 3) NCEP $T_{a}$ shows often a warm bias; and 4) the mean absolute error for ice thicknesses up to 20 cm is $pm$4.7 cm. Based on these results, we conclude that, despite the shortcomings of the NCEP data (coarse spatial resolution and no polynyas), this data set is appropriate in combination with MODIS $T_{s}$ for the retrieval of TITs up to 20 cm in the Laptev Sea region. The TIT algorithm can be applied to other polynya regions and to past and future time periods. Our TIT product is a valuable data set for verification of other model and remote sensing ice thickness data

Are environmental aspects value drivers for companies? A review of empirical studies

"Umweltaspekte und ihre Wertrelevanz für die Unternehmen: Eine Zusammenfassung existierender empirischer Forschungsergebnisse!" (diese Version ist nicht mehr aktuell! 03.04.2007) The management of the value of a firm requires the identification of important value drivers. The main objective of the paper is to find out whether value based management (e.g. shareholder value oriented management) has to take into account environmental aspects. In order to answer this question, the paper will determine whether there is an empirically proven relationship between the economic and environmental performance of companies. The paper is divided into three main parts: The development of a basic theory, the examination of existing empirical results and the concluding integration of theory with empirical results. Basic Theory: To build a basis, the paper first specifies the theoretical connection between economic and environmental performance of companies. Economic performance (e.g. definable by financial statement and/or capital market data) and environmental performance (e.g. definable by operational and strategic data) are linked in a model. Based on the model the influence of environmental aspects on corporate value is examined resulting in seven hypotheses for the relationship of environmental and economic performance. Empirical Results: In order to test the developed theoretical relation, empirical studies are identified and assessed, with regard to the relationship between economic and environmental performance. The research results in 122 studies from all over the world, which are subject to further investigation. The analyzing process includes different steps. First, the studies are divided and reviewed as far as their empirical method and soundness are concerned. Mainly they can be differentiated in regression, event and portfolio studies. Furthermore the study categorizes the environmental and economic variables used in the analyzed studies. Economic measures are divided into the following categories: market based measures (e.g. stock price), accounting based measures (e.g. RoA), accounting and market based measures (e.g. Tobins q), perceived performance measures (i.e. derived from questionnaires) and miscellaneous measures (e.g. shadow prices). Environmental measures on the other hand are divided into the seven categories: strategic environmental performance, operational environmental performance, questionnaires, rating/ranking, events, environmental disclosure and mutual funds. The next step identifies the empirical result of every study as well as important determinants (e.g. the distinguished environmental and economic categories) of the results. The objective is to show whether general patterns for the existence of different results can be defined. Overall it can be shown that about 40% of all studies report a significant positive relationship between economic and environmental performance, contrary to only 11% reporting significant negative results. Furthermore, in order to assess the special role of environmental aspects as value drivers 23 suitable studies are analyzed on the basis of Rappaport?s shareholder network. Results provide an even stronger evidence for the value creating role of environmental aspects. Conclusion: Finally we can detect statistically proven environmental value drivers combining theoretical and empirical research. At the same time, the empirical methods are also evaluated, especially with regard to there ability to provide useful support for the development and examination of the theoretical research. Overall it seems to the authors that the whole research on the topic runs parallel and is not combined. There are only a few studies who are built on already recognized relations or which try the confirm such relations. Based on these cornerstones, requirements for further empirical research are identified and specified

Thermally induced magnetic switching in bit-patterned media

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Journal of Applied Physics 122, 043907 (2017) and may be found at https://doi.org/10.1063/1.4992808.We have studied the thermal variation of the switching field of magnetic islands at room temperature. A model bit-pattern media composed of an assembly of islands with 80 nm width was fabricated by sputter deposition onto a pre-patterned substrate. Using direct magnetic-contrast imaging of the islands under applied field, we extract the switching probabilities of individual islands. Based on an analytical model for the thermally activated switching of the islands, we are able to determine the intrinsic magnetic anisotropy of each island and, consequentially, a distribution of anisotropies for the island ensemble investigated. In the distribution, we identify a separated group of islands with a particularly small anisotropy. We attribute this group to islands containing misaligned grains triggering the magnetic reversal. At room temperature and slow field sweep rates, the observed thermal broadening of the switching-field distribution is small compared to the intrinsic broadening. However, we illustrate that thermal fluctuations play a crucial role at high sweep rates by extrapolating our results to technological relevant regimes

Silicon-on-insulator polarization rotating micro-ring resonator

We propose a novel micro-ring resonator which uses quasi-TE polarized light in the bus waveguide to excite the quasi-TM polarized modes in a micro-ring. An all-pass filter is demonstrated on Silicon-on-Insulator

On the Selection of Measures to Quantify Organisational Performance

In the last decade measuring a company´s performance exclusively financially has been heavily criticised. Consequently, different performance measurement systems including the Balanced Scorecard, the Performance Pyramid, and the Quantum Performance were developed, discussed and implemented in industry. Besides the financial perspective, additional perspectives (e.g. customers, processes, employess, etc) have been considered. Organisational performance is assumed to be a multidimensional phenomenon today. Hence one important aspect of the discussion of several concepts of performance measurement has been the selection of the right measures. This paper focused the problemof measuring multidimensional organisational performance. Based on the multitask agency theory we enhanced the approaches of Holmstrom/milgrom and Austin by introducing extrinsic and intrinsic motivation, cost of measurement and uncertainty of measurement into the model

Hurdles for the Voluntary Disclosure of Information on Intangibles - Empirical Results for 'New Economy' Industries

The importance of intangible assets like brands, customer relationships, knowledge or organisational capabilities is increasing in most western economies. Recent concepts like knowledge management or intellectual capital underline the growing importance of these "soft" production factors. The financial as well as the managerial accounting are still focusing on "hard" production factors, especially the production area with their typically physical and tangible assets and the finance and investment area with financial assets. This paper is focusing on possibilities and limits of reporting on intangible resources seen from the companies point of view. We examined 343 German listed corporations of the German C-DAX indices for industries where intangible resources play a significant role for the business models of the companies (Pharmaceuticals & Health, Software, Technology, Media and Telecommunications).Using a pre-tested questionnaire the sample finally consits of 54 companies (response rate = 16 %),that could be used for the analysis