Representation and Encoding of Heterogeneous Data in a Web Based Research Environment for Manuscript and Textual Studies

This paper describes the general architecture of a digital research environment for manuscript and textual studies (particularly those pertaining to ancient Greek and Byzantine texts), and it discusses some questions of data representation and encoding in the framework of such an online research platform. The platform is being developed by the project Teuchos. Zentrum für Handschriften- und Textforschung, established in 2007 by the Institut für Griechische und Lateinische Philologie (Universität Hamburg) in cooperation with the Aristoteles-Archiv (Freie Universität Berlin). Teuchos is a long-term infrastructural project of the Universität Hamburg. It is currently in its three-year initial phase which is being co-funded by the German Research Foundation (DFG) through the "Thematic Information Networks" scheme within the "Scientific Library Services and Information Systems" programme. We introduce the main object types to be handled by our system and describe the overall functionality of the online platform. The paper focuses on the representations of two main object types: manuscripts as textual witnesses and watermarks, with an emphasis on the former. Since the adequate encoding of different layers of structure of a transmitted text is particularly relevant to optimising users' choices of navigating both digital images of the containing manuscripts and trancriptions of the text contained, this topic is discussed in some detail. We introduce the formal data model and the corresponding encoding for the object types discussed. The project encodes textual data in XML, aiming for TEI conformance where possible. Since no accepted XML model exists for the encoding of metadata within a watermark collection, we briefly explain how we chose to model the objects to accomodate the collections the project is making accessible

Ocean Dynamics and the Inner Edge of the Habitable Zone for Tidally Locked Terrestrial Planets

Recent studies have shown that ocean dynamics can have a significant warming effect on the permanent night sides of 1 to 1 tidally locked terrestrial exoplanets with Earth-like atmospheres and oceans in the middle of the habitable zone. However, the impact of ocean dynamics on the habitable zone's boundaries (inner edge and outer edge) is still unknown and represents a major gap in our understanding of this type of planets. Here we use a coupled atmosphere-ocean global climate model to show that planetary heat transport from the day to night side is dominated by the ocean at lower stellar fluxes and by the atmosphere near the inner edge of the habitable zone. This decrease in oceanic heat transport (OHT) at high stellar fluxes is mainly due to weakening of surface wind stress and a decrease in surface shortwave energy deposition. We further show that ocean dynamics have almost no effect on the observational thermal phase curves of planets near the inner edge of the habitable zone. For planets in the habitable zone's middle range, ocean dynamics moves the hottest spot on the surface eastward from the substellar point. These results suggest that future studies of the inner edge may devote computational resources to atmosphere-only processes such as clouds and radiation. For studies of the middle range and outer edge of the habitable zone, however, fully coupled ocean-atmosphere modeling will be necessary. Note that due to computational resource limitations, only one rotation period (60 Earth days) has been systematically examined in this study; future work varying rotation period as well as other parameters such as atmospheric mass and composition is required.Comment: 34 pages, 13 figures, and 1 tabl

Differences in Water Vapor Radiative Transfer among 1D Models Can Significantly Affect the Inner Edge of the Habitable Zone

An accurate estimate of the inner edge of the habitable zone is critical for determining which exoplanets are potentially habitable and for designing future telescopes to observe them. Here, we explore differences in estimating the inner edge among seven one-dimensional radiative transfer models: two line-by-line codes (SMART and LBLRTM) as well as five band codes (CAM3, CAM4_Wolf, LMDG, SBDART, and AM2) that are currently being used in global climate models. We compare radiative fluxes and spectra in clear-sky conditions around G and M stars, with fixed moist adiabatic profiles for surface temperatures from 250 to 360 K. We find that divergences among the models arise mainly from large uncertainties in water vapor absorption in the window region (10 μm) and in the region between 0.2 and 1.5 μm. Differences in outgoing longwave radiation increase with surface temperature and reach 10–20 W m^(−2); differences in shortwave reach up to 60 W m^(−2), especially at the surface and in the troposphere, and are larger for an M-dwarf spectrum than a solar spectrum. Differences between the two line-by-line models are significant, although smaller than among the band models. Our results imply that the uncertainty in estimating the insolation threshold of the inner edge (the runaway greenhouse limit) due only to clear-sky radiative transfer is ≈10% of modern Earth's solar constant (i.e., ≈34 W m^(−2) in global mean) among band models and ≈3% between the two line-by-line models. These comparisons show that future work is needed that focuses on improving water vapor absorption coefficients in both shortwave and longwave, as well as on increasing the resolution of stellar spectra in broadband models