scholarly journals Supersymmetric solutions of the cosmological, gauged, ℂ magic model

2018 ◽  
Vol 2018 (5) ◽  
Author(s):  
Samuele Chimento ◽  
Tomás Ortín ◽  
Alejandro Ruipérez
Keyword(s):  
Magic Model

Modelling the Effects of Acid Deposition: Estimation of Long-Term Water Quality Responses in Forested Catchments in Finland

1988 ◽  
Vol 19 (2) ◽  
pp. 99-120 ◽  
Author(s):  
A. Lepistö ◽  
P. G. Whitehead ◽  
C. Neal ◽  
B. J. Cosby
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Base Cations ◽  
Surface Water Quality ◽  
Mineral Weathering ◽  
Co2 Solubility ◽  
Forested Catchments ◽  
Deposition Rates ◽  
Magic Model

A modelling study has been undertaken to investigate long-term changes in surface water quality in two contrasting forested catchments; Yli-Knuutila, with high concentrations of base cations and sulphate, in southern Finland; and organically rich, acid Liuhapuro in eastern Finland. The MAGIC model is based on the assumption that certain chemical processes (anion retention, cation exchange, primary mineral weathering, aluminium dissolution and CO2 solubility) in catchment soils are likely keys to the responses of surface water quality to acidic deposition. The model was applied for the first time to an organically rich catchment with high quantities of humic substances. The historical reconstruction of water quality at Yli-Knuutila indicates that the catchment surface waters have lost about 90 μeq l−1 of alkalinity in 140 years, which is about 60% of their preacidification alkalinity. The model reproduces the declining pH levels of recent decades as indicated by paleoecological analysis. Stream acidity trends are investigated assuming two scenarios for future deposition. Assuming deposition rates are maintained in the future at 1984 levels, the model indicates that stream pH is likely to continue to decline below presently measured levels. A 50% reduction in deposition rates would likely result in an increase in pH and alkalinity of the stream, although not to estimated preacidification levels. Because of the high load of organic acids to the Liuhapuro stream it has been acid before atmospheric pollution; a decline of 0.2 pH-units was estimated with increasing leaching of base cations from the soil despite the partial pH buffering of the system by organic compounds.

scholarly journals Predicting long-term recovery of a strongly acidified stream using MAGIC and climate models (Litavka, Czech Republic)

2008 ◽  
Vol 12 (2) ◽  
pp. 479-490 ◽  
Author(s):  
D. W. Hardekopf ◽  
J. Horecký ◽  
J. Kopáček ◽  
E. Stuchlík
Keyword(s):  
Czech Republic ◽  
Climate Models ◽  
Climate Model ◽  
Stream Water ◽  
Regional Climate ◽  
Chemical Recovery ◽  
Factors Affecting ◽  
Magic Model ◽  
Acid Tolerant ◽  
Acid Atmospheric Deposition

Abstract. Two branches forming the headwaters of a stream in the Czech Republic were studied. Both streams have similar catchment characteristics and historical deposition; however one is rain-fed and strongly affected by acid atmospheric deposition, the other spring-fed and only moderately acidified. The MAGIC model was used to reconstruct past stream water and soil chemistry of the rain-fed branch, and predict future recovery up to 2050 under current proposed emissions levels. A future increase in air temperature calculated by a regional climate model was then used to derive climate-related scenarios to test possible factors affecting chemical recovery up to 2100. Macroinvertebrates were sampled from both branches, and differences in stream chemistry were reflected in the community structures. According to modelled forecasts, recovery of the rain-fed branch will be gradual and limited, and continued high levels of sulphate release from the soils will continue to dominate stream water chemistry, while scenarios related to a predicted increase in temperature will have little impact. The likelihood of colonization of species from the spring-fed branch was evaluated considering the predicted extent of chemical recovery. The results suggest that the possibility of colonization of species from the spring-fed branch to the rain-fed will be limited to only the acid-tolerant stonefly, caddisfly and dipteran taxa in the modelled period.

scholarly journals Predicting long-term recovery of a strongly acidified stream using MAGIC and climate models (Litavka, Czech Republic)

2007 ◽  
Vol 4 (5) ◽  
pp. 3285-3315
Author(s):  
D. W. Hardekopf ◽  
J. Horecký ◽  
J. Kopáček ◽  
E. Stuchlík
Keyword(s):  
Czech Republic ◽  
Climate Models ◽  
Climate Model ◽  
Stream Water ◽  
Regional Climate ◽  
Chemical Recovery ◽  
Factors Affecting ◽  
Magic Model ◽  
Acid Tolerant ◽  
Acid Atmospheric Deposition

Abstract. Two branches forming the headwaters of a stream in the Czech Republic were studied. Both streams have similar catchment characteristics and historical deposition; however one is rain-fed and strongly affected by acid atmospheric deposition, the other spring-fed and only moderately acidified. The MAGIC model was used to reconstruct past stream water and soil chemistry of the rain-fed branch, and predict future recovery up to 2050 under current proposed emissions levels. A future increase in air temperature calculated by a regional climate model was then used to derive climate-related scenarios to test possible factors affecting chemical recovery up to 2100. Macroinvertebrates were sampled from both branches, and differences in stream chemistry were reflected in the community structures. According to modelled forecasts, recovery of the rain-fed branch will be gradual and limited, and continued high levels of sulphate release from the soils will continue to dominate stream water chemistry, while scenarios related to a predicted increase temperature will have little impact. The likelihood of colonization of species from the spring-fed branch was evaluated considering the predicted extent of chemical recovery. The results suggest that the possibility of colonization of species from the spring-fed branch to the rain-fed will be limited to only the acid-tolerant stonefly, caddisfly and dipteran taxa in the modelled period.

scholarly journals Predicting regional recovery from acidification; the MAGIC model applied to Scotland, England and Wales

1998 ◽  
Vol 2 (4) ◽  
pp. 543-554 ◽  
Author(s):  
C. D. Evans ◽  
A. Jenkins ◽  
R. C. Helliwell ◽  
R. Ferrier
Keyword(s):  
Surface Water ◽  
Significant Proportion ◽  
Chemical Properties ◽  
Regional Patterns ◽  
Surface Water Chemistry ◽  
Surface Water Acidification ◽  
Magic Model ◽  
Recovery From Acidification ◽  
The Uk ◽  
Physical And Chemical

Abstract. A dynamic, process-based model of surface water acidification, MAGIC, has been applied to over a thousand sites across the UK. The model is calibrated to surface water samples collected during a survey for the Critical Loads programme, and utilises the best available and consistent estimates of soil physical and chemical properties, rainfall and runoff volumes, and deposition chemistry. A total of 698 sites were calibrated successfully. At these sites, surface water chemistry was reconstructed from 1850 to the present day, and forecast to 2050 based on future decreases in sulphur (S) deposition in response to the Second S Protocol. Model outputs capture distinct regional patterns of acidification and recovery. the most acidic present-day conditions are found in acid-sensitive regions of Northern England (the Pennines, Lake District and North York Moors). Although a significant proportion of sites in these areas failed to calibrate, those that did are predicted to have experienced severe historic decreases in acidic neutralising capacity (ANC) in response to high levels of acidic deposition. The model also indicates significant acidification in the moderate deposition areas of Wales and Galloway, whereas in the low deposition region of northern Scotland, acidification has been minor even in areas of acid-sensitive geology. ANC is forecast to recover at virtually all sites, with the greatest recovery predicted for areas currently subject to high deposition. The model indicates that the Second S Protocol, however, will not be sufficient to produce full recovery, with average ANC increases to 2050 counteracting just 27% of the simulated decline from 1850 to present day. Acidic conditions (ANC < 0) are predicted to persist until 2050 at a significant number of sites in Northern England, Wales and Galloway.

scholarly journals Modelling long-term changes in stream water and soil chemistry in catchments with contrasting vulnerability to acidification (Lysina and Pluhuv Bor, Czech Republic)

2003 ◽  
Vol 7 (4) ◽  
pp. 525-539 ◽  
Author(s):  
J. Hruška ◽  
P. Krám
Keyword(s):  
Czech Republic ◽  
Critical Loads ◽  
Soil Chemistry ◽  
Stream Water ◽  
Base Saturation ◽  
Soil Base ◽  
Magic Model ◽  
Water Ph ◽  
Annual Discharge ◽  
Gothenburg Protocol

Abstract. In two Czech catchments covered by Norway spruce forests, the MAGIC model was used to simulate annual stream water and soil chemistry for the period 1851–2030. These two sites represent geochemical end-members of ecosystem sensitivity to acidification (acid-sensitive granitic Lysina catchment vs. acid-resistant serpentinitic Pluhuv Bor catchment). Although the total deposition of sulphur to the catchments declined by 75% between 1990 and 2002, the recovery of stream water pH was relatively small over this period. At Lysina, the annual discharge-weighted mean pH of stream water increased only from 3.92 to 4.01, although SO4 concentration declined very sharply from 570 μeq L–1 in 1990 to 150 μeq L–1 in 2002. Stream water buffering was caused mainly by dissociation of organic acids. At Pluhuv Bor, the annual mean pH varied inversely with the annual discharge. Stream water concentrations of SO4 declined dramatically at Pluhuv Bor, from 1040 μeq L–1 in 1992 to 220 μeq L–1 in 2002. Using atmospheric deposition as specified in the Gothenburg Protocol, the model predicts that, at Lysina, stream water pH will increase to 4.3 and soil base saturation will increase to 6.0% by 2030 (from 5.6% in 2002); corresponding pre-industrial stream water pH was simulated to be 5.5 and soil base saturation to be 25%. At Pluhuv Bor, the pre-industrial pH was estimated to be 7.2 and the corresponding base saturation was 94%. Large anthropogenic acidification in the 20th century caused only a small decline in pH (to 6.9) and base saturation (to 88%). Simulations in accordance with the Gothenburg Protocol predict that the pH should increase by 0.2 pH units and the base saturation by 1% by 2030. Under this protocol, critical loads of atmospheric deposition for SO4 and NO3 will not be exceeded at Pluhuv Bor but will be exceeded at Lysina. Keywords: MAGIC model, catchment, critical loads, Gothenburg Protocol, soil and water acidification, granite, serpentinite, Czech Republic

scholarly journals Modelling seasonal nitrate concentrations in runoff of a heathland catchment in SW Norway using the MAGIC model: I. Calibration and specification of nitrogen processes

2009 ◽  
Vol 40 (2-3) ◽  
pp. 198-216 ◽  
Author(s):  
Anne Merete S. Sjøeng ◽  
Richard F. Wright ◽  
Øyvind Kaste
Keyword(s):  
Acidic Deposition ◽  
N Deposition ◽  
Snow Accumulation ◽  
Long Term Effects ◽  
Time Step ◽  
Surface Water Chemistry ◽  
Magic Model ◽  
Best Fit ◽  
Annual Time

MAGIC (the Model of Acidification of Groundwater In Catchments) has been widely applied on catchments all over the world. The model has been used with annual time resolution to simulate the long-term effects of acidic deposition on surface water chemistry. Here MAGIC was applied using a monthly time step. The purpose was to simulate observed seasonal nitrate (NO3) concentrations and fluxes at an upland heathland catchment in southwestern Norway during the period 1993–2004. The rates of the key ecosystem nitrogen (N) processes (mineralization, plant uptake, litterfall and immobilization) were assumed to be governed by temperature. A snow accumulation and melt routine was used. The rates were calibrated to obtain the best match between the observed and simulated NO3 patterns. The best fit was obtained with standard yearly cycles for deposition and N parameters. The results show that MAGIC can explain 68 and 88% of the variation in seasonal NO3 concentrations and fluxes, respectively. The calibrated model provides a tool for exploring the effects of future scenarios of climate change and N deposition on NO3 in streamwater.

scholarly journals Modelling the recovery of surface water chemistry and the ecological implications in the British uplands

2003 ◽  
Vol 7 (4) ◽  
pp. 456-466 ◽  
Author(s):  
R. C. Helliwell ◽  
A. Jenkins ◽  
R. C. Ferrier ◽  
B. J. Cosby
Keyword(s):  
Surface Water ◽  
Base Cation ◽  
Surface Water Chemistry ◽  
Close Match ◽  
Acid Neutralising Capacity ◽  
Magic Model ◽  
Ecological Implications ◽  
Chemical Conditions ◽  
The Uk ◽  
Gothenburg Protocol

Abstract. Abstract: The MAGIC (Model of Acidification of Groundwaters in Catchments) model has been calibrated to three acid sensitive regions in the UK: Galloway, the South Pennines and Wales. These calibrations use the best available data for surface water, soil and deposition, from several UK data bases and regional sampling programmes. The model is capable of reproducing observed base cation and acid anion concentrations as reflected by a close match between observed and simulated acid neutralising capacity (ANC). Predictions to 2016 under currently agreed emission reductions, the Gothenburg Protocol, show that ANC greater than zero will be achieved at 100%, 86% and 100% of sites in Galloway, the Pennines and Wales, respectively. This indicates the potential for biological recovery and a return to ‘good status’ although chemical conditions remain some way from simulated pre-acidification conditions. In the longer term, beyond 2036 (20 years after compliance with the Gothenburg protocol), the model indicates that increased N leakage to surface waters may cause deterioration in the chemical status. Keywords: recovery, acidification, modelling, upland UK, ecology

scholarly journals A two-layer application of the MAGIC model to predict the effects of land use scenarios and reductions in deposition on acid sensitive soils in the UK

1998 ◽  
Vol 2 (4) ◽  
pp. 497-507 ◽  
Author(s):  
R. C. Helliwell ◽  
R. C. Ferrier ◽  
A. Jenkins
Keyword(s):  
Land Use ◽  
Soil Acidification ◽  
Critical Loads ◽  
Base Saturation ◽  
Organic Soils ◽  
Layer Model ◽  
Magic Model ◽  
Land Use Scenarios ◽  
Two Layer Model ◽  
The Uk

Abstract. A two-layer application of the catchment-based soil and surface water acidification model, MAGIC, was applied to 21 sites in the UK Acid Waters Monitoring Network (AWAMN), and the results were compared with those from a one-layer application of the model. The two-layer model represented typical soil properties more accurately by segregating the organic and mineral horizons into two separate soil compartments. Reductions in sulphur (S) emissions associated with the Second S Protocol and different forestry (land use) scenarios were modelled, and their effects on soil acidification evaluated. Soil acidification was assessed in terms of base saturation and critical loads for the molar ratio of base cations (CA2+ + MG 2+ + K+) to aluminium (Al) in soil solution. The results of the two-layer application indicate that base saturation of the organic compartment was very responsive to changes in land use and deposition compared with the mineral soil. With the two- layer model, the organic soil compartment was particularly sensitive to acid deposition, which resulted in the critical load being predicted to be exceeded at eight sites in 1997 and two sites in 2010. These results indicate that further reductions in S deposition are necessary to raise the base cation (BC):Al ratio above the threshold which is harmful to tree roots. At forested sites BC:Al ratios were generally well below the threshold designated for soil critical loads in Europe and forecasts indicate that forest replanting can adversely affect the acid status of sensitive term objectives of protecting and sustaining soil and water quality. Policy formulation must seek to protect the most sensitive environmental receptor, in this case organic soils. It is clear, therefore, that simply securing protection of surface waters, via the critical loads approach, may not ensure adequate protection of low base status organic soils from the effects of acidification.

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