Temperature and evaporation dynamics of saline solutions

Oroud, Ibrahim M.

doi:10.1016/s0022-1694(99)00138-9

Cited by 24 publications

(13 citation statements)

References 23 publications

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“…Therefore, in case important water exchanges between the VCL and the aquifer occur, they would decrease the surface water salinity and contribute to lowering the longitudinal salinity gradients along the system, because the groundwater salinity is not being evapoconcentrated as in the VCL2. Regarding the volume conservation in the entire system, the inverse relationship between the net evaporation rate and water salinity (Oround 1999;Lensky et al 2005) should be included in the computation of the actual evaporation rates from VCL2. According to Oround (1999) and Lensky et al (2005), this inverse relationship decreases the water saturation in the air because of reductions in the free energy of water molecules.…”

Section: Resultsmentioning

confidence: 99%

“…Regarding the volume conservation in the entire system, the inverse relationship between the net evaporation rate and water salinity (Oround 1999;Lensky et al 2005) should be included in the computation of the actual evaporation rates from VCL2. According to Oround (1999) and Lensky et al (2005), this inverse relationship decreases the water saturation in the air because of reductions in the free energy of water molecules. To take into account this process, the parameter b is introduced such that the evaporated mass E kg m 22 s 21 is computed as…”

Section: Resultsmentioning

confidence: 99%

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Temporal and spatial features of the thermohydrodynamics of shallow salty lagoons in northern Chile

Fuente

Ninóo

2009

Limnology & Oceanography

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Salares in the altiplanic region of Chile, Bolivia, and Argentina sustain important ecosystems in small, shallow wetlands, with inflows provided by groundwater and outflows consisting mainly of evaporation. The temporal and spatial thermohydrodynamics of one of these extremely shallow, saline, endorheic wetlands in northern Chile is analyzed on the basis of field observations of water temperature and salinity, and low-dimensionality models accounting for conservation of heat, mass, and volume. Temperature in the studied system is spatially homogeneous but with strong daily oscillations. Salinity, on the other hand, exhibits longitudinal gradients from the zone of (salty) groundwater upwelling to the final evaporation lagoon. Heat balance in the system is largely controlled by wind, as the evaporative heat flux balances out the net solar radiation. Heat exchange with the bottom sediments damps the daily temperature oscillations by retaining (releasing) heat from (to) the water column. Simulated longitudinal profiles of salinity and flow discharge agree reasonably well with field observations but salinity effects on the rates of both evaporation and salt precipitation need to be taken into account. Laboratory experiments were conducted to develop a simple model for the former effect while the latter effect was accounted for by using existing information. Field measurements provided calibration of the model parameters. The observed longitudinal salinity gradients are correlated with the biological structure of the associated ecosystem to explain, for instance, the existence of specific flamingos' feeding areas in the system.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Temporal and spatial features of the thermohydrodynamics of shallow salty lagoons in northern Chile

Fuente

Ninóo

2009

Limnology & Oceanography

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“…The energy balance at the surface-atmosphere boundary may be written in the following form (e.g., Oroud 1998;1999): ), respectively. Solar radiation is estimated from sunshine hours and extraterrestrial radiation at the top of the atmosphere; the latter is determined by solar declination and geographic latitude (S ext =f(δ, φ)).…”

Section: Methods Of Investigationmentioning

confidence: 99%

“…4 shows the dependence of average monthly vapor pressure on average monthly air temperature in the two stations situated near the drainage basin, Rabba and Ghor Safi. Given this strong linkage, actual vapor pressure for each cell is determined using the following expression (Oroud 1999) …”

Section: Model Inputmentioning

confidence: 99%

Water Budget Assessment within a Typical Semiarid Watershed in the Eastern Mediterranean

Oroud

2015

Environ. Process.

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Adequate evaluation of blue water fluxes in arid and semiarid areas is crucial for operational purposes such as evaluation of rain-fed agriculture, grazing potentials and for designing and construction of water dams. Evapotranspiration, runoff and deep recharge in such catchments are poorly understood due to the lack of meteorological and/or hydrological measurements. Modeling using proper parameterizations would probably be a viable alternative to gauge such resources. The present paper examines the water budget in a typical medium size semiarid watershed located in the mountainous areas in Jordan using a transient model. The watershed was discretized into 1 km side length, and the model was run for six continuous years using a daily time step. Many parameterizations used in the model were based on field measurements carried out in this particular environment where measurements of many hydrometeorological parameters are scarce. Comparison between simulated results and long-term flow observations show that the model performs adequately. Results indicate that evapotranspiration, surface runoff, and deep recharge constitute around 87.5, 7.5 and 5 % of areal precipitation, respectively. Significant runoff occurs over steep terrains where vegetation cover is limited or devoid, implying the production of large quantities of sediments, which would adversely affect water quality and the life span of dams constructed over these catchments.

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“…The energy budget of a hypersaline solution with an initial activity of β 1 , assuming thermal equilibrium (net heat storage within the water body ~0) and analogy between heat and water vapour transfer, may be expressed in the following form (e.g., Oroud, , ):

S ((), 1 - α) + L ↓ - ε_{s} σ {T_{s 1}}^{4} - italicψf ((), u) ((), T_{normals 1} - T_{a}) - f ((), u) ((), β_{1} e_{normals 1} - e_{a}) - Q_{normalG 1} = 0,

where S is solar radiation (W m −2 ), α is total surface albedo, L ↓ is atmospheric radiation (W m −2 ), ε s is surface emissivity, σ is the Stefan–Boltzmann constant (5.667 × 10 −8 W m −2 K −4 ), ψ is the psychrometric constant (hPa K −1 ), f ( u ) is the wind function (W m −2 hPa −1 ), T s1 , T a , e s1 , e a , Q G1 , and β 1 are surface temperature, air temperature, saturation vapour pressure at temperature T s1 , ambient vapour pressure, heat flux across the lake bottom (W m −2 ), and the activity coefficient of the hypersaline solution.…”

Section: Theoretical Frameworkmentioning

confidence: 99%

Evaporites: Relative humidity control of primary mineral facies revisited

Oroud

2018

Hydrological Processes

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It is widely accepted that the deposition of mineral facies of evaporite basins is controlled by the average annual relative humidity of the contiguous atmosphere, which dictates the equilibrium activity of the evaporating brine. This concept has far reaching implications in salt works and for the investigation of paleoenvironmental settings affecting depositional sequences within evaporite basins. The above concept, which dominated the scientific thought of evaporite basin investigations, suffers from two serious flaws: (a) the assumption of a static decoupled atmosphere and (b) the total neglect of energy input and thermodynamic feedbacks resulting from evaporation suppression. The present investigation will resolve the underlying mechanisms controlling the equilibrium activity of hypersaline solutions using a theoretical framework that combines energy and mass transport across the surface–atmosphere boundary. Calculations of the equilibrium activity of hypersaline solutions under isothermal conditions, as implied in the original concept, are not in line with the basic physical principles defining heat and mass exchange across the brine–atmosphere boundary and lead to substantial overestimation of actual evaporation and the activity itself. It is demonstrated that in addition to atmospheric relative humidity, the activity of hypersaline solutions is determined by numerous meteorological forcings along with hydrological, geochemical, and thermodynamic feedback mechanisms. Evaporation suppression resulting from a drop in brine activity causes substantial increase in brine temperature, which enhances vapour pressure differential across the interface, leading to more evaporation. This negative feedback shifts the brine activity downward for equilibrium to be attained. It is also demonstrated that evaporation from a brine surface usually proceeds when the relative humidity of the contiguous atmosphere is similar or even higher than that of the brine due to energy input and the strong negative feedback caused by evaporation suppression. The present investigation re‐establishes a new paradigm concerning the processes controlling evaporite basin sedimentation and palaeoclimate reconstruction as deduced from evaporite/hypersaline basin deposits. Findings have operational ramifications in the industrial applications of dissolved salt mineral extraction.

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Temperature and evaporation dynamics of saline solutions

Cited by 24 publications

References 23 publications

Temporal and spatial features of the thermohydrodynamics of shallow salty lagoons in northern Chile

Temporal and spatial features of the thermohydrodynamics of shallow salty lagoons in northern Chile

Water Budget Assessment within a Typical Semiarid Watershed in the Eastern Mediterranean

Evaporites: Relative humidity control of primary mineral facies revisited

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