1,120 research outputs found
AbschÀtzung der Meereisproduktion in der Laptev-See mit dem Ozean-Meereismodell NAOSIM
Fernerkundungsdaten haben eine kontinuierliche Abnahme des Meereises in den vergangenen 30 Jahren gezeigt, Klimamodelle prognostizieren eine anhaltende Abnahme fĂŒr die Zukunft. Dies erfordert eine genauere Analyse der verursachenden Prozesse, der Trendentwicklung und der regionalen VariabilitĂ€t. Dabei spielt die Laptev-See in der sibirischen Arktis eine bedeutende Rolle, da es hier, bedingt durch eine groĂe Polynja-AktivitĂ€t, zur vermehrten Eisproduktion kommt.
Zur nĂ€heren Untersuchung der verursachenden thermodynamischen und dynamischen Prozesse nutzen wir eine mit tĂ€glichen NCEP/NCAR-Daten angetriebene Simulation mit dem gekoppelten Ozean-Meereismodell NAOSIM (North Atlantic/Arctic Ocean-Sea Ice Model) von 1990-2008 mit 0.08° Auflösung. Aufgrund seiner realitĂ€tsnahen Wiedergabe des mittleren Jahresgangs und des negativen Trends der Eisbedeckung ist dieses Modell fĂŒr die Auswertung gut geeignet.
Die getrennte Analyse der thermodynamischen Eisproduktion bzw. Eisschmelze und der dynamischen Umverteilung fĂŒr die gesamte Arktis bestĂ€tigt, dass im Bereich der Laptev-See die Eisproduktion im Mittel 850km3/a gröĂer ist als die Eisschmelze. Dieses Eis wird von der Laptev-See in die zentrale Arktis exportiert. In der gesamten Arktis nimmt das Eisvolumen im Mittel um -450km3/a von 1990-2008 ab. usammenhĂ€nge zwischen der Eisproduktion der Laptev-See und des Eisvolumens der Arktis werden mittels einer Zeitreihenananlyse untersucht. Die EntstehungsgrĂŒnde fĂŒr Extremjahre (Bsp.: Minimum 2007, Maximum 1996) werden aufgezeigt und ihre regionalen Folgen in der Arktis diskutiert
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Pictures in Your Mind: Using Interactive Gesture-Controlled Reliefs to Explore Art
Tactile reliefs offer many benefits over the more classic raised line drawings or tactile diagrams, as depth, 3D shape, and surface textures are directly perceivable. Although often created for blind and visually impaired (BVI) people, a wider range of people may benefit from such multimodal material. However, some reliefs are still difficult to understand without proper guidance or accompanying verbal descriptions, hindering autonomous exploration.
In this work, we present a gesture-controlled interactive audio guide (IAG) based on recent low-cost depth cameras that can be operated directly with the hands on relief surfaces during tactile exploration. The interactively explorable, location-dependent verbal and captioned descriptions promise rapid tactile accessibility to 2.5D spatial information in a home or education setting, to online resources, or as a kiosk installation at public places.
We present a working prototype, discuss design decisions, and present the results of two evaluation studies: the first with 13 BVI test users and the second follow-up study with 14 test users across a wide range of people with differences and difficulties associated with perception, memory, cognition, and communication. The participant-led research method of this latter study prompted new, significant and innovative developments
Spatial Structuring and Life History Connectivity of Antarctic Silverfish Along the Southern Continental Shelf of the Weddell Sea
A multi-disciplinary approach was employed to examine a physical-biological population hypothesis for a critical forage species, the Antarctic silverfish Pleuragramma antarctica. Caccavo et al. (2018; Sci Rep 8:17856) had shown strong gene flow along the westward Antarctic Slope Current, in addition to spatially recurring length modes that provided evidence for episodic connectivity. In this paper, otolith nucleus chemistry from a subset of fish collected in the southern Weddell Sea as part of a hydrographic survey of the Filchner Trough system was used to test between connectivity scenarios. Nucleus chemistry, which reflects environmental exposure during early life, showed significant spatial structuring despite homogeneity in microsatellite allele frequencies. Mg:Ca and Sr:Ca differentiated length modes, and Mg:Ca showed significant contrasts between Atka Bay, Halley Bay, and Filchner Trough. Physical-biological mechanisms may help reconcile structuring shown by otolith chemistry, length, and abundance data with prior evidence of gene flow. Such mechanisms include self-recruitment shaped by circulation associated with the Filchner Trough, fluctuations in mixing between immigrant and locally recruited fish, and feeding opportunities between inflowing Modified Warm Deep Water and outflowing Ice Shelf Water. The results illustrate how comparisons between multi-disciplinary techniques based on integrated sampling designs that incorporate hydrography can enhance understanding of population structure and connectivity around the Southern Ocean
On the warm inflow at the eastern boundary of the Weddell Gyre
The Weddell Sea plays an important role for the global oceans and climate by being one of the biggest production and export areas of Antarctic Bottom Water (AABW). Circumpolar Deep Water (CDW) enters the Weddell Gyre (WG) at its eastern boundary. Then called Warm Deep Water (WDW), it is a major contributor to the formation of deep and bottom waters due to ocean-ice shelf interactions in the southern and soutwestern Weddell Sea. Hydrographic data collected between 0 and 30°E on the RV Polarstern cruise ANT XX/2 reveals a two-core structure for the eastern inflow of warm water at roughly 20°E but not further downstream at the Greenwich meridian (GM). Model results and climatological fields suggest that the two cores represent two separate modes of warm inflow. One mode is driven by eddy mixing in the northeastern corner of the WG and the other one is an advective mode, forming the southern branch of the inflow which extends beyond 30°E before turning westward. Both pathways are likely to carry waters from different origins within the Antarctic Circumpolar Current (ACC), where more ventilated CDW is found at the Southern Boundary (SB) compared to the centre. The southern route shows considerable interannual variability in the model. A variable inflow of two types of CDW together with admixed recirculated and cooler waters from the Weddell Sea can potentially contribute to the observed variability and warming trend of WDW over the last decade at the GM
Developing an assessment of epistemic trust: a research protocol
Epistemic trust (ET) describes the willingness to accept new information from another person as trustworthy, generalizable, and relevant. It has been recently proposed that a pervasive failure to establish epistemic trust may underpin personality disorders. Although the introduction of the concept of ET has been inspiring to clinicians and is already impacting the field, the idea that there may be individual differences in ET has yet to be operationalized and tested empirically. This report illustrates the development of an Epistemic trust assessment and describes the protocol for its validation. The sample will include 60 university students. The Trier Social Stress Test for Groups will be administered to induce a state of uncertainty and stress, thereby increasing the relevance of information for the participants. The experiment will entail asking information from the participants about their performance and internal states during a simulated employment interview, and then tracking how participants are able to revise their own judgments about themselves in light of the feedback coming from an expert committee. To control for social desirability and personality disorder traits, the short scale for social desirability (Kurzskala Soziale ErwuÌnschtheit-Gamma) and the Inventory of Personality Organization are utilized. After the procedure, the participants will complete an app-based Epistemic trust questionnaire (ETQ) app. Confirmatory Factor Analysis will be utilized to investigate the structure and dimensionality of the ETQ, and ANOVAs will be used to investigate mean differences within and between persons for ET scores by item category. This study operationalizes a newly developed ET paradigm and provides a framework for the investigation of the theoretical assumptions about the connection of ET and personality functioning
On the Modified Warm Deep Water flow toward the Filchner Ronne Ice Shelf: Observations and Model Results
The Filchner Ronne Ice Shelf (FRIS), located in the southern Weddell Sea, plays a key role in the dense water formation, which is a precursor of AABW in the world ocean. Today, the ice shelf is protected by a large cold continental shelf. Model studies, however, have suggested the potential for an increased flow of Modified Warm Deep Water (MWDW) toward and under FRIS via the Filchner Trough, causing a substantial increase in basal melt rates by the end of this century. Historic data in the region suffer from a strong summer bias. New two-year long mooring time series from 2014 to 2016 reveal a distinct seasonal cycle in hydrography along the eastern flank of the Filchner Trough, with a southward flow of MWDW only in summer, connected to a seasonal shoaling of the Antarctic Slope Front (ASF). With the goal of analysing the seasonal and interannual variability of this warm inflow, we set up a new global configuration for the Finite Element Sea-ice Ocean Model (FESOM) with increased resolution over the Weddell Sea and eddy-permitting resolution over the continental shelves. We find a strong sensitivity of the on-shelf flow of MWDW to the representation of the general Weddell Gyre circulation and in particular the ASF properties upstream of the Filchner Trough. Both improve significantly with the new high-resolution grid. In order to ensure a correct representation of the water masses encountering the Filchner Trough, which is necessary to study the inflow dynamics and variability, we perform an experiment with restoring the upstream temperature and salinity field over the continental slope. For this, a monthly climatology at17°W compiled from historic data was incorporated into the World Ocean Data Atlas
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