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- Sleincour, Johan Peter, 1714-1785
(author)
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Disputatio philosophica, sistens cogitationes nonnullas, de gustus varietate, ejusque usu politico, quam, consens. ampliss. colleg. philosoph. in regia academia upsaliensi, præside, Mag. Joh. Petro Sleincour, ... Stipendiarius Kåhreanus, Johannes David Rogberg, smolandus. In audit. Carol. maj. die XX. maji. a. MDCCLXXII.
- 1772
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Doctoral thesis (other academic/artistic)
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- Asokan, Shilpa M., et al.
(author)
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Climate model performance and change projection for freshwater fluxes : comparison for irrigated areas in Central and South Asia
- 2016
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In: Journal of Hydrology. - : Elsevier BV. - 2214-5818. ; 5, s. 48-65
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Journal article (peer-reviewed)abstract
- Study region: The large semi-arid Aral Region in Central Asia and the smaller tropical Mahanadi River Basin (MRB) in India. Study focus: Few studies have so far evaluated the performance of the latest generation ofglobal climate models on hydrological basin scales. We here investigate the performanceand projections of the global climate models in the Coupled Model Intercomparison Project, Phase 5 (CMIP5) for freshwater fluxes and their changes in two regional hydrological basins, which are both irrigated but of different scale and with different climate. New hydrological insights for the region: For precipitation in both regions, model accuracy relative to observations has remained the same or decreased in successive climate model generations until and including CMIP5. No single climate model out-performs other models across all key freshwater variables in any of the investigated basins. Scale effects are not evident from global model application directly to freshwater assessment for the two basins of widely different size. Overall, model results are less accurate and more uncertain for freshwater fluxes than for temperature, and particularly so for model-implied water storage changes. Also, the monsoon-driven runoff seasonality in MRB is not accurately reproduced. Model projections agree on evapotranspiration increase in both regions until the climatic period 2070–2099. This increase is fed by precipitation increase in MRB and by runoff water (thereby decreasing runoff) in the Aral Region.
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- Bring, Arvid, et al.
(author)
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Implications of freshwater flux data from the CMIP5 multimodel output across a set of Northern Hemisphere drainage basins
- 2015
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In: EARTHS FUTURE. - 2328-4277. ; 3:6, s. 206-217
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Journal article (peer-reviewed)abstract
- The multimodel ensemble of the Coupled Model Intercomparison Project, Phase 5 (CMIP5) synthesizes the latest research in global climate modeling. The freshwater system on land, particularly runoff, has so far been of relatively low priority in global climate models, despite the societal and ecosystem importance of freshwater changes, and the science and policy needs for such model output on drainage basin scales. Here we investigate the implications of CMIP5 multimodel ensemble output data for the freshwater system across a set of drainage basins in the Northern Hemisphere. Results of individual models vary widely, with even ensemble mean results differing greatly from observations and implying unrealistic long-term systematic changes in water storage and level within entire basins. The CMIP5 projections of basin-scale freshwater fluxes differ considerably more from observations and among models for the warm temperate study basins than for the Arctic and cold temperate study basins. In general, the results call for concerted research efforts and model developments for improving the understanding and modeling of the freshwater system and its change drivers. Specifically, more attention to basin-scale water flux analyses should be a priority for climate model development, and an important focus for relevant model-based advice for adaptation to climate change.
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4. |
- Bring, Arvid, et al.
(author)
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Variability in climate change simulations affects needed long-term riverine nutrient reductions for the Baltic Sea
- 2015
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In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 44, s. 381-391
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Journal article (peer-reviewed)abstract
- Changes to runoff due to climate change may influence management of nutrient loading to the sea. Assuming unchanged river nutrient concentrations, we evaluate the effects of changing runoff on commitments to nutrient reductions under the Baltic Sea Action Plan. For several countries, climate projections point to large variability in load changes in relation to reduction targets. These changes either increase loads, making the target more difficult to reach, or decrease them, leading instead to a full achievement of the target. The impact of variability in climate projections varies with the size of the reduction target and is larger for countries with more limited commitments. In the end, a number of focused actions are needed to manage the effects of climate change on nutrient loads: reducing uncertainty in climate projections, deciding on frameworks to identify best performing models with respect to land surface hydrology, and increasing efforts at sustained monitoring of water flow changes.
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5. |
- Rogberg, Peter, et al.
(author)
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Kolmogorov-Sinai entropy for the A+B -> P reaction in transitional flows
- 2004
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In: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 120:14, s. 6423-6429
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Journal article (peer-reviewed)abstract
- We study global decay of the bimolecular reaction A+B-->P as c(t)similar tot(-alpha) in a nonlinear transitional flow. A relationship is established between the decay exponent alpha, and a modified Kolmogorov-Sinai entropy, h(r). We find that for dynamic conditions which induce relatively strong mixing, the decay exponent is alphaproportional toln psi(r)(-Bh) with B being a characteristic reactive mix-down time for the system, and psi is a space-time scaling parameter. Dynamic conditions which imply weak mixing lead to a degenerate dependence of alpha on h(r). The proposed relationship between alpha on h(r) should be a useful link between the dynamical evolution of the flow field and reaction kinetics in vortex dominated flows.
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7. |
- Törnqvist, Rebecka, et al.
(author)
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Evolution of the hydro-climate system in the Lake Baikal basin
- 2014
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In: Journal of Hydrology. - : Elsevier BV. - 0022-1694 .- 1879-2707. ; 519, s. 1953-1962
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Journal article (peer-reviewed)abstract
- Climatic changes can profoundly alter hydrological conditions in river basins. Lake Baikal is the deepest and largest freshwater reservoir on Earth, and has a unique ecosystem with numerous endemic animal and plant species. We here identify long-term historical (1938-2009) and projected future hydro-climatic trends in the Selenga River Basin, which is the largest sub-basin (>60% inflow) of Lake Baikal. Our analysis is based on long-term river monitoring and historical hydro-climatic observation data, as well as ensemble mean and 22 individual model results of the Coupled Model Intercomparison Project, Phase 5 (CMIP5). Study of the latter considers a historical period (from 1961) and projections for 2010-2039 and 2070-2099. Observations show almost twice as fast warming as the global average during the period 1938-2009. Decreased intra-annual variability of river discharge over this period indicates basin-scale permafrost degradation. CMIP5 ensemble projections show further future warming, implying continued permafrost thaw. Modelling of runoff change, however, is highly uncertain, with many models (64%) and their ensemble mean failing to reproduce historical behaviour, and with indicated future increase being small relative to the large differences among individual model results.
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