scholarly journals Phosphorus mass balance and input load estimation from the wet and dry periods in tropical semiarid reservoirs

2021 ◽  
Author(s):  
Maria de Jesus Delmiro Rocha ◽  
Iran Eduardo Lima Neto
Keyword(s):  
Mass Balance ◽  
Phosphorus Release ◽  
High Density ◽  
Balance Model ◽  
Wet Season ◽  
Total Load ◽  
Brazilian Semiarid ◽  
Input Load ◽  
Load Types ◽  
The Impact

Abstract The dynamics of total phosphorus (TP) in 18 strategic reservoirs of the high-density reservoir network of the Brazilian semiarid was evaluated during the wet and dry periods for the past 12 years. Seasonal TP concentrations presented no significant differences for about 90% of the reservoirs (p > 0.05). This was attributed to a trade-off between the hydrological/limnological processes occurring in the two seasons. Then, a transient complete-mix mass balance model was applied with particular adaptations for the tropical semiarid reservoirs to estimate the TP load for each season. Because of the relatively well mixed conditions and high hypolimnetic dissolved oxygen concentrations during the wet season, the wet load was assumed to represent the external TP load. On the other hand, because of the absence of reservoir inflow during the dry season, phosphorus release under anoxic sediment conditions and wind-induced resuspension under shallow water conditions, the dry load was assumed to reflect the internal TP load. The maximum external loads were related to peak inflows, notably after drought periods. Consistently, the largest internal loads were obtained during the drought periods, when the reservoirs were shallower and more prone to phosphorus release and resuspension. By comparing the impact of the two input load types, the wet period load was predominant in 72% of the reservoirs. The areal phosphorus loads ranged from 0.66 to 7.29 gP.m².yr-1, which were consistent with the literature, despite the very high density of reservoirs. Finally, power-law curves including data for all studied reservoirs were adjusted between the dry period load and volume, dry and wet period loads, wet period load and inflow, and total load and catchment area, resulting in satisfactory R² (0.66–0.82).

scholarly journals Sensitivity of mountain glacier mass balance to changes in bare-ice albedo

2017 ◽  
Vol 58 (75pt2) ◽  
pp. 119-129 ◽  
Author(s):  
Kathrin Naegeli ◽  
Matthias Huss
Keyword(s):  
Mass Balance ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Landsat 8 ◽  
Glacier Surface ◽  
Mountain Glacier ◽  
Albedo Feedback ◽  
In Situ Data ◽  
The Impact ◽  
Near Future

ABSTRACT Albedo is an important parameter in the energy balance of bare-ice surfaces and modulates glacier melt rates. The prolongation of the ablation period enforces the albedo feedback and highlights the need for profound knowledge on impacts of bare-ice albedo on glacier mass balance. In this study, we assess the mass balance sensitivity of 12 Swiss glaciers with abundant long-term in-situ data on changes in bare-ice albedo. We use pixel-based bare-ice albedo derived from Landsat 8. A distributed mass-balance model is applied to the period 1997–2016 and experiments are performed to assess the impact of albedo changes on glacier mass balance. Our results indicate that glacier-wide mass-balance sensitivities to changes in bare-ice albedo correlate strongly with mean annual mass balances (r 2 = 0.81). Large alpine glaciers react more sensitively to bare-ice albedo changes due to their ablation areas being situated at lower elevations. We find average sensitivities of glacier-wide mass balance of −0.14 m w.e. a−1 per 0.1 albedo decrease. Although this value is considerably smaller than sensitivity to air temperature change, we stress the importance of the enhanced albedo feedback that will be amplified due to atmospheric warming and a suspected darkening of glacier surface in the near future.

scholarly journals What glaciers are telling us about Earth's changing climate

2014 ◽  
Vol 8 (4) ◽  
pp. 3475-3491
Author(s):  
W. Tangborn ◽  
M. Mosteller
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Balance Model ◽  
Mountain Glaciers ◽  
Established Relationship ◽  
Representative Selection ◽  
Meteorological Observations ◽  
Glacier Ablation ◽  
The Impact ◽  
Selection Of

Abstract. A glacier monitoring system has been developed to systematically observe and document changes in the size and extent of a representative selection of the world's 160 000 mountain glaciers (entitled the PTAAGMB Project). Its purpose is to assess the impact of climate change on human societies by applying an established relationship between glacier ablation and global temperatures. Two sub-systems were developed to accomplish this goal: (1) a mass balance model that produces daily and annual glacier balances using routine meteorological observations, (2) a program that uses Google Maps to display satellite images of glaciers and the graphical results produced by the glacier balance model. The recently developed PTAA glacier balance model is described and applied to eight glaciers to produce detailed mass balance reports. Comparing annual balances produced by the model to traditional manual measurements for 50–60 years yields R2 values of 0.50–0.60. The model also reveals an unusual but statistically significant relationship between the average ablation of Wrangell Range glaciers and global temperatures that have been derived from temperature data at 7000 stations in the Northern Hemisphere. This glacier ablation/global temperature relationship provides the means to use worldwide ablation results to anticipate problems caused by climate change.

scholarly journals Modelling the impact of superimposed ice on the mass balance of an Arctic glacier under scenarios of future climate change

2005 ◽  
Vol 42 ◽  
pp. 277-283 ◽  
Author(s):  
Andrew Wright ◽  
Jemma Wadham ◽  
Martin Siegert ◽  
Adrian Luckman ◽  
Jack Kohler
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Climate Model ◽  
Global Climate Model ◽  
Balance Model ◽  
Explicit Calculation ◽  
Future Climate Change ◽  
Glacier Mass Balance ◽  
Positive Contribution ◽  
The Impact

AbstractA surface-energy/mass-balance model with an explicit calculation of meltwater refreezing and superimposed ice formation is applied to midre Lovénbreen, Spitsbergen, Svalbard. The model is run with meteorological measurements to represent the present climate, and run with scenarios taken from global climate model predictions based on the IS92a emissions scenario to represent future climates. Model results indicate that superimposed ice accounts for on average 37% of the total net accumulation under present conditions. The model is found to be highly sensitive to changes in the mean annual air temperature and much less sensitive to changes in the total annual precipitation. A 0.5˚C decade–1 temperature increase is predicted to cause an average mass-balance change of –0.43 ma–1, while a 2% decade–1 increase in precipitation will result in only a +0.02 ma–1 change in mass balance. An increase in temperature results in a significant decrease in the size of the accumulation area at midre Lovénbreen and hence a similar decrease in the net volume of superimposed ice. The model predicts, however, that the relative importance of superimposed ice will increase to account for >50% of the total accumulation by 2050. The results show that the refreezing of meltwater and in particular the formation of superimposed ice make an important positive contribution to the mass balance of midre Lovénbreen under present conditions and will play a vital future role in slowing down the response of glacier mass balance to climate change.

scholarly journals A model study of the energy and mass balance of Chhota Shigri glacier in the Western Himalaya, India

2011 ◽  
Vol 5 (1) ◽  
pp. 95-129 ◽  
Author(s):  
F. Pithan
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Climate Model ◽  
Monsoon Season ◽  
Regional Climate ◽  
Western Himalaya ◽  
Reanalysis Data ◽  
Balance Model ◽  
Mass Balances ◽  
The Impact

Abstract. The impact of climate change on Himalaya mountain glaciers is increasingly subject of public and scientific debate. However, observational data are sparse and important knowledge gaps remain in the understanding of what drives changes in these glaciers' mass balances. The present study investigates the glacier regime on Chhota Shigri, a benchmark glacier for the observation of climate change in the monsoon-arid transition zone of Western Himalaya. Results of an energy-balance model driven by reanalysis data and the observed mass balances from three years on 50 m altitude intervals across the glacier display a correlation coefficient of 0.974. Contrary to prior assumptions, monsoon precipitation accounts for a quarter to a third of total accumulation. It has an additional importance because it lowers the surface albedo during the ablation season. Results confirm radiation as the main energy source for melt on Himalaya glaciers. Latent heat flux acts as an important energy sink in the pre-monsoon season. Mass balance is most sensitive to changes in atmospheric humidity, changing by 900 mm w.e. per 10% change in humidity. Temperature sensitivity is 220 mm w.e.K−1. Model results using 21st century anomalies from a regional climate model based on the SRES A2 scenario suggest that a monsoon increase might offset the effect of warming.

scholarly journals Distributed mass-balance and climate sensitivity modelling of Engabreen, Norway

2005 ◽  
Vol 42 ◽  
pp. 395-401 ◽  
Author(s):  
Thomas V. Schuler ◽  
Regine Hock ◽  
Miriam Jackson ◽  
Hallgeir Elvehøy ◽  
Matthias Braun ◽  
...  
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
High Sensitivity ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Index Method ◽  
Temperature And Precipitation ◽  
Simple Mass ◽  
Climate Station ◽  
The Impact

AbstractAssessing the impact of possible climate change on the water resources of glacierized areas requires a reliable model of the climate–glacier-mass-balance relationship. In this study, we simulate the mass-balance evolution of Engabreen, Norway, using a simple mass-balance model based on daily temperature and precipitation data from a nearby climate station. Ablation is calculated using a distributed temperature-index method including potential direct solar radiation, while accumulation is distributed linearly with elevation. The model was run for the period 1974/75–2001/02, for which annual mass-balance measurements and meteorological data are available. Parameter values were determined by a multi-criteria validation including point measurements of mass balance, mass-balance gradients and specific mass balance. The modelled results fit the observed mass balance well. Simple sensitivity experiments indicate a high sensitivity of the mass balance to temperature changes, as expected for maritime glaciers. The results suggest, further, that the mass balance of Engabreen is more sensitive to warming during summer than during winter, while precipitation changes affect almost exclusively the winter balance.

scholarly journals The impact of climate change on future frontal variations of Briksdalsbreen, western Norway

2009 ◽  
Vol 55 (193) ◽  
pp. 789-796 ◽  
Author(s):  
Tron Laumann ◽  
Atle Nesje
Keyword(s):  
Mass Balance ◽  
Response Times ◽  
Time Lag ◽  
Balance Model ◽  
Climate Scenarios ◽  
Climate Data ◽  
Outlet Glacier ◽  
Surface Mass ◽  
Western Norway ◽  
The Impact

AbstractA flowline model, coupled with a surface mass-balance model forced by climate data from Bergen, was used to simulate future frontal changes of Briksdalsbreen, a western outlet glacier from Jostedalsbreen, western Norway, under various future climate scenarios. The model was used to calculate the time-lag of frontal response to a sudden and short change in the mass balance. According to the model, the front has a time-lag for maximum advance rate of 4–5 years, in close agreement with previous studies. The response time for Briksdalsbreen was calculated by running the model for 200 years with different mass-balance perturbations. For mass-balance perturbations of +0.3 and +0.6 m w.e. the model yields response times of 52 and 60 years, respectively. We ran the model from 1963 to 2007 with measured mass-balance data, and from 2007 to 2085 using calculated mass balances from 12 different climate scenarios. The model predicts retreat up the steep valley from the lake inlet, with a total frontal retreat of 2.5–5.0 km by 2085. A spectacular icefall, one of the main tourist attractions in western Norway, may thus disappear and the glacier may become a plateau glacier that will gradually melt down.

scholarly journals Can fish introductions alter nutrient cycles in previously fishless high-latitude lakes?

2016 ◽  
Author(s):  
Marco Milardi ◽  
Jyrki Lappalainen ◽  
Suzanne McGowan ◽  
Jan Weckstrom
Keyword(s):  
Mass Balance ◽  
Nutrient Dynamics ◽  
Size Structure ◽  
Balance Model ◽  
Nutrient Load ◽  
Mass Balance Model ◽  
Introduced Fish ◽  
Bioenergetic Model ◽  
Fish Introduction ◽  
Total Load

<p>The additional input and enhanced cycling of nutrients derived from introduced fish can be a significant factor altering nutrient dynamics in oligotrophic lakes. To test this, we used a bioenergetic model to estimate the fish-derived nutrient load in Lake Kuutsjärvi, a historically fishless boreal lake of northern Fennoscandia. The lake was selected because of the absence of other anthropogenic stressors, a known stocking history and the possibility of quantitatively estimating the size-structure and biomass of the fish population through a mass removal. Subsequently, we used a mass balance model to compare fish-derived nutrients with other nutrient load pathways. For comparison over longer timescales, we used lake sediment records of diatoms, chlorophyll and carotenoid pigments, C:N ratios and stable isotopes to infer whether fish introduction produced detectable changes in the lake trophic state, primary productivity and terrestrial nutrient input. Based on the nutrient mass balance model, we found that phosphorus and nitrogen derived from fish were 0.46% and 2.2%, respectively, of the total load to the lake, suggesting that fish introduction could not markedly increase the nutrient load. Accordingly, the palaeolimnological record indicated little increase in primary production but instead a shift from pelagic to benthic production after fish introduction.</p>

scholarly journals Mass-balance estimates for Haut Glacier d’Arolla, Switzerland, from 2000 to 2006 using DEMs and distributed mass-balance modeling

2008 ◽  
Vol 49 ◽  
pp. 22-26 ◽  
Author(s):  
Ruzica Dadic ◽  
Javier G. Corripio ◽  
Paolo Burlando
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Snow Water Equivalent ◽  
Aerial Photographs ◽  
Balance Model ◽  
Accurate Estimation ◽  
Ice Melt ◽  
Modeling Approach ◽  
The Impact ◽  
Snow And Ice

AbstractA distributed mass-balance modeling approach is required to assess the impact of future climate scenarios on water availability in glaciated basins. Accurate estimation of water stored within the snow, firn and ice of such basins requires knowledge of the distributed snow and ice mass balance throughout the year. In this study, we estimate the annual mass balance and runoff for Haut Glacier d′Arolla, Switzerland, from 2000 to 2006. Our estimations are based on observed elevation changes from three digital elevation models (DEMs) derived from aerial photographs in September 1999 and 2005, and October 2006. In addition to these estimations, we implement a combined field observation and a distributed mass-balance modeling approach. An energy-balance model driven by meteorological variables from automatic weather stations inside the catchment area, including gravitational snow transport, is run for the period 2005–06. The model results are validated with direct snow water equivalent measurements as well as with runoff measurements. Combining the mass-balance measurements, energy-balance calculations and measured runoff, we estimate the contribution from ice melt to the runoff for this period to be 25–30%, the contribution from snowmelt 50–60% and the contribution from rain 15–25%. Our model results also show that the snow distribution affects both snow and ice melt. It is therefore important for water resources management to understand the distribution of snow in alpine catchments, as it seems to be the controlling factor for the timing of streamflow throughout the year as well as for the total availability of water.

scholarly journals Municipal Solid Waste Mass Balance as a Tool for Calculation of the Possibility of Implementing the Circular Economy Concept

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1811
Author(s):  
Grzegorz Wielgosiński ◽  
Justyna Czerwińska ◽  
Szymon Szufa
Keyword(s):  
Waste Management ◽  
Municipal Solid Waste ◽  
Mass Balance ◽  
Solid Waste ◽  
Circular Economy ◽  
Management System ◽  
Municipal Waste ◽  
Balance Model ◽  
Waste Management System ◽  
The Impact

Municipal waste management system modeling based on the mass balance of individual waste streams allows us to answer the question of how the system will react to organizational changes, e.g., to the expected reduction in the amount of plastics or the introduction of a deposit for glass and/or plastic packaging. Based on the data on Polish municipal solid waste and the forecast of changes in its quantity and composition, as well as demographic data, a balance model was prepared to assess the impact of introducing higher and higher levels of recycling, in accordance with the circular economy assumptions on the waste management system. It has been shown that, for the Polish composition of municipal waste, even if the assumed recycling levels of individual streams are achieved, achieving the general target level of 65% recycling in 2025/30 may not be feasible. The possibility of achieving a higher level of recycling will be possible due the introduction of selective ash collection from individual home furnaces, while the impact of reducing the amount of plastics or introducing a deposit on packaging is minimal. The calculations also showed that, to complete the waste management system in Poland, we need at least 3.5 million Mg/year of incineration processing capacity and the present state (approx. 1.3 million Mg/year) is insufficient.

Development of basinal scale glacier mass balance model: an approach based on satellite observation and energy balance components

2020 ◽  
Author(s):  
Akansha Patel ◽  
Ajanta Goswami ◽  
Thamban Meloth ◽  
Parmanand Sharma
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Water Resource Management ◽  
Water Storage ◽  
Balance Model ◽  
Future Climate Change ◽  
Glacier Mass Balance ◽  
Observation Data ◽  
Basin Scale ◽  
The Impact

&lt;p&gt;The understanding of fresh water storage in the Himalayan region is essential for water resource management of the region. As glacier mass balance is a difference between the input and output water storage in a glacier over a period, glacier mass balance can be used as an indirect method to understand the storage. In the northwestern Himalaya, microscale meteorological stations are needed for mass balance estimation due to rugged terrain and complex topography of this region. However, there are only few meteorological stations available in that region. Therefore, in this study, we have developed a new model for glacier mass balance estimation at basinal scale. This model &amp;#160;includes the parameterization of energy balance components viz. albedo, longwave radiation, shortwave radiation, sensible heat, latent heat and heat flux at spatial and temporal scale using earth observation data. The modeling of air temperature is performed using the multi-regression analysis over the Chenab basin of the Indian Himalayas. Simulation is driven with the 16-days Landsat optical and thermal data from 2015 to 2018 that can be used for parameterization of the variable. This model is calibrated and validated with the field data of period 2015-2016. Further, the impact of climatic change and their influence on mass balance was also assessed to understand the future glacier health and mass changes. In contrast to previous temperature index based basin scale models, this model includes most of the energy balance components for better estimation of glacier mass balance. The model can also be used to estimate possible responses of the world&amp;#8217;s glaciers to future climate change.&lt;/p&gt;

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