959 research outputs found

    Understanding Unpredictability: On the Responses to and the Valence of the Unpredicted and the Unpredictable

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    Unpredictability constitutes a deeply ingrained phenomenon of our everyday lives. At some times, things happen unpredictedly, breaking our hitherto existing expectations and filling us with surprise; at other times, we neither hold expectations nor make predictions, and what will happen will do so unpredictably. Both the unpredicted and the unpredictable have been subject to extensive previous research endeavors which have spawned a bunch of heterogeneous theories and evidence, controversial debates, and a range of open questions. In this dissertation, I investigate the cause and structure of responses to surprise and the valence of the unpredicted and the unpredictable to foster a successive integration of single threads and to increase the psychological understanding of unpredictability. Chapter 1 introduces the relevant theoretical background and provides an overview on the current literature. Chapter 2 investigates the effects of the degree of deviance and expectation constraints on the behavioral, affective, experiential, and cognitive responses to unpredicted, surprising events. The evidence obtained in two experiments suggests that the key driving mechanism of surprise is unexpectedness and not the ease of making sense of an event. Beyond that, the behavioral, experiential, and cognitive responses to surprise apparently unfold in a dichotomous way, distinguishing between deviance and non-deviance without being sensitive to finer gradations. On the affective dimension, the evidence points towards surprise being inherently valence-free. Chapter 3 transfers the economic principles of risk-return trade-off and risk premium to the psychological domain, investigating whether and what value people attach to predictable social interactions. Across seven experiments, I demonstrate that people are willing to forgo substantial parts of their potential returns to ensure interacting with a predictable (vs. unpredictable) partner. This suggests an overall negative valence of the unpredictable. Chapter 5 concludes with discussing implications, limitations, and future directions of the research presented

    A model-based constraint on CO<sub>2</sub> fertilisation

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    We derive a constraint on the strength of CO2 fertilisation of the terrestrial biosphere through a “top-down” approach, calibrating Earth system model parameters constrained by the post-industrial increase of atmospheric CO2 concentration. We derive a probabilistic prediction for the globally averaged strength of CO2 fertilisation in nature, for the period 1850 to 2000 AD, implicitly net of other limiting factors such as nutrient availability. The approach yields an estimate that is independent of CO2 enrichment experiments. To achieve this, an essential requirement was the incorpo- ration of a land use change (LUC) scheme into the GENIE Earth system model. Using output from a 671-member ensemble of transient GENIE simulations, we build an emulator of the change in atmospheric CO2 concentration change since the preindustrial period. We use this emulator to sample the 28-dimensional input parameter space. A Bayesian calibration of the emulator output suggests that the increase in gross primary productivity (GPP) in response to a doubling of CO2 from preindustrial values is very likely (90 % confidence) to exceed 20 %, with a most likely value of 40–60 %. It is important to note that we do not represent all of the possible contributing mechanisms to the terrestrial sink. The missing processes are subsumed into our calibration of CO2 fertilisation, which therefore represents the combined effect of CO2 fertilisation and additional missing processes. If the missing processes are a net sink then our estimate represents an upper bound. We derive calibrated estimates of carbon fluxes that are consistent with existing estimates. The present-day land–atmosphere flux (1990–2000) is estimated at −0.7 GTC yr−1 (likely, 66 % confidence, in the range 0.4 to −1.7 GTC yr−1). The present-day ocean–atmosphere flux (1990–2000) is estimated to be −2.3 GTC yr−1 (likely in the range −1.8 to −2.7 GTC yr−1). We estimate cumulative net land emissions over the post-industrial period (land use change emissions net of the CO2 fertilisation and climate sinks) to be 66 GTC, likely to lie in the range 0 to 128 GTC

    A vital link: Water and vegetation in the anthropocene

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    This paper argues that the interplay of water, carbon and vegetation dynamics fundamentally links some global trends in the current and conceivable future Anthropocene, such as cropland expansion, freshwater use, and climate change and its impacts. Based on a review of recent literature including geographically explicit simulation studies with the process-based LPJmL global biosphere model, it demonstrates that the connectivity of water and vegetation dynamics is vital for water security, food security and (terrestrial) ecosystem dynamics alike. The water limitation of net primary production of both natural and agricultural plants - already pronounced in many regions - is shown to increase in many places under projected climate change, though this development is partially offset by water-saving direct CO2 effects. Natural vegetation can to some degree adapt dynamically to higher water limitation, but agricultural crops usually require some form of active management to overcome it - among them irrigation, soil conservation and eventually shifts of cropland to areas that are less water-limited due to more favourable climatic conditions. While crucial to secure food production for a growing world population, such human interventions in water-vegetation systems have, as also shown, repercussions on the water cycle. Indeed, land use changes are shown to be the second-most important influence on the terrestrial water balance in recent times. Furthermore, climate change (warming and precipitation changes) will in many regions increase irrigation demand and decrease water availability, impeding rainfed and irrigated food production (if not CO2 effects counterbalance this impact - which is unlikely at least in poorly managed systems). Drawing from these exemplary investigations, some research perspectives on how to further improve our knowledge of human-water-vegetation interactions in the Anthropocene are outlined

    Effects of precipitation uncertainty on discharge calculations for main river basins

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    This study quantifies the uncertainty in discharge calculations caused by uncertainty in precipitation input for 294 river basins worldwide. Seven global gridded precipitation datasets are compared at river basin scale in terms of mean annual and seasonal precipitation. The representation of seasonality is similar in all datasets, but the uncertainty in mean annual precipitation is large, especially in mountainous, arctic, and small basins. The average precipitation uncertainty in a basin is 30%, but there are strong differences between basins. The effect of this precipitation uncertainty on mean annual and seasonal discharge was assessed using the uncalibrated dynamic global vegetation and hydrology model Lund-Potsdam-Jena managed land (LPJmL), yielding even larger uncertainties in discharge (average 90%). For 95 basins (out of 213 basins for which measurements were available) calibration of model parameters is problematic because the observed discharge falls within the uncertainty of the simulated discharge. A method is presented to account for precipitation uncertainty in discharge simulations

    Location as Vocation: An Urban College\u27s Engagement with Their Somali Neighbors

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    This article focuses on the significance of an urban college’s location and mission in guiding disciplines within the college to engage with its immigrant neighbors through service-learning.The authors describe how social connectedness theory and transformational learning theory were used to facilitate learning and increase students’ awareness of their sense of vocation.Student reflections on the service learning experience in both disciplines, religion and social work, are used to illustrate the application of each theory

    Advances and visions in large-scale hydrological modelling: findings from the 11th Workshop on Large-Scale Hydrological Modelling

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    Large-scale hydrological modelling has become increasingly wide-spread during the last decade. An annual workshop series on large-scale hydrological modelling has provided, since 1997, a forum to the German-speaking community for discussing recent developments and achievements in this research area. In this paper we present the findings from the 2007 workshop which focused on advances and visions in large-scale hydrological modelling. We identify the state of the art, difficulties and research perspectives with respect to the themes "sensitivity of model results", "integrated modelling" and "coupling of processes in hydrosphere, atmosphere and biosphere". Some achievements in large-scale hydrological modelling during the last ten years are presented together with a selection of remaining challenges for the future

    Effects of precipitation uncertainty on discharge calculations for main river basins

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    This study quantifies the uncertainty in discharge calculations caused by uncertainty in precipitation input for 294 river basins worldwide. Seven global gridded precipitation datasets are compared at river basin scale in terms of mean annual and seasonal precipitation. The representation of seasonality is similar in all datasets, but the uncertainty in mean annual precipitation is large, especially in mountainous, arctic, and small basins. The average precipitation uncertainty in a basin is 30%, but there are strong differences between basins. The effect of this precipitation uncertainty on mean annual and seasonal discharge was assessed using the uncalibrated dynamic global vegetation and hydrology model Lund-Potsdam-Jena managed land (LPJmL), yielding even larger uncertainties in discharge (average 90%). For 95 basins (out of 213 basins for which measurements were available) calibration of model parameters is problematic because the observed discharge falls within the uncertainty of the simulated discharge. A method is presented to account for precipitation uncertainty in discharge simulations
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