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The measurement data of single droplet evaporation experiments are often biased due to the extra heat input through the fiber suspension and the presence of thermal radiation in hot environments. This encumbers model validation for heat and mass transfer simulations of liquid droplets. In this paper, a thermal analysis of this measurement layout is presented with a coupled lumped parameter model, considering heat conduction through the suspension. The model was validated by experimental data from the literature and good agreements were found. The thermal analysis focused on fiber material and geometry, and thermal radiation properties. Calculations were performed on a broad range of ambient conditions for liquids with different volatility characteristics. Temporal squared droplet diameter- and temperature-profiles, furthermore, droplet stationary evaporation rate were used to characterize vaporization phenomena. The thermal balance of the droplet is dominated by the convective heat rate from the environment in the early stage of evaporation. The effect of heat conduction through the fiber becomes important at the end of the droplet lifetime when the droplet size is decreased. Temperature sensor suspension may seriously bias droplet temperature due to the larger thermal conductivity compared to quartz fiber. Large droplets in high-temperature environments show significant sensitivity to thermal radiation properties, which should be considered in measurements and model validation. [ABSTRACT FROM AUTHOR]

Water surface evaporation is an important process in the hydrologic and energy cycles. Accurate simulation of water evaporation is important for the evaluation of water resources. In this paper, using meteorological data from the Aixinzhuang reservoir, the main factors affecting water surface evaporation were determined by the principal component analysis method. To illustrate the influence of these factors on water surface evaporation, the paper first adopted the Dalton model to simulate water surface evaporation. The results showed that the simulation precision was poor for the peak value zone. To improve the model simulation’s precision, a modified Dalton model considering relative humidity was proposed. The results show that the 10-day average relative error is 17.2%, assessed as qualified; the monthly average relative error is 12.5%, assessed as qualified; and the yearly average relative error is 3.4%, assessed as excellent. To validate its applicability, the meteorological data of Kuancheng station in the Luan River basin were selected to test the modified model. The results show that the 10-day average relative error is 15.4%, assessed as qualified; the monthly average relative error is 13.3%, assessed as qualified; and the yearly average relative error is 6.0%, assessed as good. These results showed that the modified model had good applicability and versatility. The research results can provide technical support for the calculation of water surface evaporation in northern China or similar regions. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

A new hybrid model combining the kernel functions along with the random vector functional link neural network (RVFLN) is proposed in this paper for an effective solar power prediction. The conventional RVFLN is known for its fast learning speed, simple architecture and good generalization capabilities and allows direct connection between input and output nodes along with nonlinear enhancement nodes with random weights. However, the bottleneck of selecting the number of hidden enhancement nodes and mapping functions is still a challenging problem. To overcome these deficiencies of the conventional RVFLN, kernel functions are used for both the direct links and the hidden nodes to provide better stability, generalization and regression accuracy. Instead of using a single kernel for the enhancement nodes, this paper proposes an optimal kernel function that comprises a linear combination of weighted local kernel and a global kernel to improve the prediction accuracy of the solar power generation. This optimal kernel will be known as multi-kernel RVFLN (MK-RVFLN), and its parameters are optimized using an efficient metaheuristic evaporation-based water cycle (EVWCA-MKRVFLN) to provide accurate prediction of solar power. To validate its superior prediction accuracy, two solar power plants of 25 and 100 MW capacity in the states of New York and California are considered for 5-min- and 60-min-ahead prediction in the months of January, April, July and October. The result analysis shows that the MK-RVFLN algorithm attains better performance than many other techniques. [ABSTRACT FROM AUTHOR]

Evapotranspiration is an important process in the water cycle that represents a considerable amount of moisture lost to the atmosphere through evaporation from the soil and wet surfaces, and transpiration from plants. Therefore, several water management methods, such as irrigation scheduling and hydrological impact analysis, rely on an accurate estimation of evapotranspiration rates. Often, daily reference evapotranspiration is modelled based on the Penman, Priestley-Taylor or Hargraeves equation. However, each of these models requires extensive input data, such as daily mean temperature, wind speed, relative humidity and solar radiation. Yet, in design studies, such data may be unavailable and therefore, another approach may be needed that is based on stochastically generated time series. More specifically, when rainfall-runoff models are used, these evapotranspiration data need to be consistent with the accompanying (stochastically generated) precipitation time series data. In this paper, such an approach is presented in which the statistical dependence between evapotranspiration, precipitation and temperature is described by three- and four-dimensional vine copulas. Based on a case study of 72 years of evapotranspiration, temperature and precipitation data, observed in Uccle, Belgium, it is shown that canonical vine copulas (C-vines) perform very well in preserving the dependences between variables. [ABSTRACT FROM AUTHOR]

Concentration measurements of evaporated hydrocarbon species by infrared laser absorption spectroscopy at a monodisperse droplet chain are presented. A droplet generator was installed within a flow channel and operated with cyclohexane, iso-octane, n-heptane, n-pentane and 1-butanol. The flow channel was flushed with a laminar flow of air at different temperatures. The absorption of a HeNe laser beam at λ = 3.39 μ m traversing through the flow channel at varying distances from the droplet chain was exploited to determine the vapor concentrations of the hydrocarbons. Measurements of the absorption cross sections in a heated gas cell ( T = 300 –773 K) enabled the quantification of the absorption signals from the droplet chain. Vapor concentrations were determined in planes perpendicular to the droplet chain. From the increase of vapor concentration between the planes, the evaporation rate could be determined. The evaporation rates were measured in dependence of co-flow temperature, droplet velocity, droplet generation frequency and droplet spacing. In the investigated temperature range of the air (313–430 K) the evaporation rates increased linearly with temperature. The order of the fuels with respect to evaporation rates corresponded with the boiling points of the individual fuels. In addition to the presentation of the results, the paper discusses the performance of vapor concentration measurements by laser absorption spectroscopy at droplet chains which has not been tested before in such a configuration. Particular attention was paid to the spatial resolution of the measurement. The results are well suited to validate models and numerical simulations. [ABSTRACT FROM AUTHOR]

The globe is facing an increase in water demand associated with an increase in the world population especially in developing countries. The increasing population urges an additional agricultural land and irrigation water. Traditional system of irrigation water supplier is open canals which allow a high percentage of water dissipation and evaporation. This paper presents a new approach to evaluate design alternatives of Improved Field Irrigation Canals (IFIC) using Life Cycle Cost (LCC) methods. LCC is a methodology for calculating the total cost of a system from inception to disposal taking into account the time value of money. The main objective of this paper is using LCC to evaluate irrigation improvement canals to save water and increase agricultural production. Four methods such: i) Net Present Value (NPV); ii) Benefit/Cost ratio (BCR); iii) Internal Rate of Return (IRR), and iv) Pay Back Period (PBP) are used to compare between three IFIC design alternatives. These alternatives are i) pipeline with one pump at canal head, ii) pipeline with one pump at the head and one pump at the middle, and iii) lined open canal and compared to the reference case; i.e. open canal. Results show that the best economic alternative for IFIC is pipeline with one pump at the intake of the canal. [ABSTRACT FROM AUTHOR]

The average evaporation in Iran is 3 times higher than the world average. Applying chemical monolayers on water surfaces is one of the promising methods for suppressing the evaporation. Literature studies have shown that the mixture of cetyl and stearyl (ratio of 1 to 9) is the state-of-the-art monolayer to minimize the evaporation. Adding calcium hydroxide increases the spreading rate and self-healing of the monolayer. Despite long study and investigation on monolayers, there are inconsistencies in explaining the mechanism by which monolayers decrease the evaporation. The mechanisms used to explain the evaporation reduction are: (i) increasing the reflected solar radiation, (ii) dampening the waves formed by winds and decreasing the water surface area, consequently, and (iii) limiting the escape of water molecules. In this paper, by design of experiments (DOE), we try to answer the above question. Evaporation rate from a container in absence of wind or low wind (~0.2 m/s) and at moderate temperature and relative humidity (~20 °C and 45%) is ~ 10 mm/day. Utilization of the monolayer can save 41% of the evaporated water. Also, in absence of radiation, a 9 m/s wind caused ~ 15 mm/day evaporation. By increasing the wind speed from 0 to 9 m/s, effectiveness of the monolayer deteriorated from 60 to 13%. Therefore, the main mechanism is neither reflecting the radiation (as in absence of radiation, monolayer was still effective) nor dampening the waves and decreasing the surface area (as in absence of wind, monolayer was effective; also, at higher wind speeds where the surface area increases, monolayer efficiency decreases). Therefore, the main mechanism by which monolayers decrease the evaporation rate is limiting the escape of water molecules. So, monolayers may be effective even during the nights even though radiation is at its lowest. [ABSTRACT FROM AUTHOR]

Within the last two decades, a large number of articles were published that report, as the authors claim, 'metastable phase equilibria', or 'metastable solubilities'. The main objective of these studies was to carry out experiments under conditions closely meeting those in solar evaporation ponds or industrial evaporation–crystallization processes. Occasionally, such studies were subject to controversial discussion and criticism and the question was raised whether metastable equilibrium data are worth being published at all. This paper provides a critical discussion of such evaporation experiments. The thermodynamic background of stable and metastable solubility and typical experimental difficulties in solubility determinations are discussed in detail. We also demonstrate that the knowledge of metastable equilibria is very useful in different research areas such as geochemistry or industrial application of solubility equilibria. Finally, it is shown that so-called 'isothermal evaporation method' used in the above-mentioned studies does not yield stable or metastable solubilities. [ABSTRACT FROM AUTHOR]

A lasting decrease in the near-surface wind speed (SWS) in China has been revealed, but a following short-term strengthening in the SWS was rarely noted. In this paper, the daily mean SWS observed datasets from 328 measurement stations in Eastern China during the period 1981–2011 were used to investigate the facts and causes of the observed short-term strengthening in winter SWS in recent decades. The major results are summarized as follows: the SWS showed a significant decrease in the last 30 years, but a short-term strengthening in SWS was observed during the winter since 2000 in Eastern China. The SWS in Eastern China showed a significant decrease of − 0.11 m s−1 decade−1 from 1981 to 1999, followed by a weak increase of 0.0008 m s−1 decade−1 from 2000 to 2011. The short-term strengthening in the SWS since 2000 was mainly induced by the changes of the pressure-gradient force (PGF), which could be attributed to the changes of the sea-level pressure (SLP) in the region (51°–69.75° N, 51.75°–111.75° E). Furthermore, the changes of the PGF during the two periods of 1981–1999 and 2000–2011 were consistent with those of the SLP in the region (51°–69.75° N, 51.75°–111.75° E). The correlation coefficient between PGF and SLP was 0.32 and 0.66 during the period 1981–1999 and 2000–2011, respectively. Therefore, the effects of the changes in SLP over the region (51°–69.75° N, 51.75°–111.75° E) on changes of SWS in the Eastern China should be significant. [ABSTRACT FROM AUTHOR]

Urea-water solution (UWS) has been widely used in selective catalytic reduction (SCR) system as reductant to generate ammonia. The position where UWS nozzle should be located is a concerned issue and worth a deep investigation. Although UWS droplet evaporates and decomposes once it has been sprayed from the nozzle, the decomposition of droplet may be still incomplete if the distance between nozzle and reactor is not long enough. Thus, the incomplete decomposed UWS droplets will collect at the entrance of reactor, which is not beneficial for droplet evaporation, system flow and SCR efficiency. This paper presents the position where UWS nozzle should be placed from the perspective of evaporation and decomposition of UWS droplet. A numerical model of UWS droplet evaporation and decomposition was established in this paper and the droplet displacement is solved by adding droplet motion equation to the simulation model. The results can provide a practical help for designing a urea-SCR system. [ABSTRACT FROM AUTHOR]

Evaporation and vertical moisture and heat transfer from the underlying surface are the basis of cloud formation. The situation when the coming relatively cold stably stratified air moves over a warm ocean is a typical problem in the development of a turbulent convective layer. The problem of cloud formation is also of scientific and practical interest. This paper considers the problems of the formation of a turbulent convective layer over a warmer ocean and the vertical distribution of relative humidity. The results of the theoretical model are compared with the data of observations of the development of the turbulent convective layer at low latitudes (in the Indian Ocean) and at higher latitudes (in autumn over Lake Michigan). Approximate equations describe well the dynamics of temperature and humidity of the layer as a function of the difference between the temperatures of the approaching and near-surface air layers. The theoretical results are compared with the data on measurements of the condensation heights obtained at the Novosibirsk Tolmachevo Airport. Some discrepancy between them is due to the unsteadiness measurement and the approximations adopted in the theoretical model. [ABSTRACT FROM AUTHOR]

Hydrothermal scheduling is a vital step in power system operational planning. It deals with the coordinated operation of hydel and thermal machines so that the cost of production of electrical energy is minimum subject to the satisfaction of the constraints. This paper presents the solution of non-convex short-term hydrothermal scheduling due to valve point effects using an improved version of a meta-heuristic method water cycle algorithm called as evaporation rate-based water cycle algorithm (ERWCA). ERWCA is a nature inspired algorithm based on hydrologic cycle of water that how the raindrops form streams and these streams flow to the rivers and sea. The feasibility and effectiveness of ERWCA have been tested on different hydrothermal test systems consisting of four hydel units configured with one thermal, three thermal and ten thermal units involving all the constraints. The results obtained from these simulations have been compared with other methods such as DE, PSO and GA, and they show that the solutions obtained from ERWCA are superior in terms of cost and computational time. Hence, the proposed ERWCA is a remarkable method for solving short-term hydrothermal scheduling problem. [ABSTRACT FROM AUTHOR]

This paper proposed a numerical formulation for unsaturated flow problems with nonlinear boundaries of seepage face and soil-atmosphere interface via the concept of parabolic variational inequality (PVI) method. A unified unilateral boundary condition was first proposed to represent the conditions on the seepage face and soil-atmosphere interface boundaries within the partial differential equation (PDE) formulation. A PVI formulation mathematically equivalent to the PDE formulation was then proposed, which automatically transforms the flux part of the unified unilateral boundary condition into the natural boundary condition and eliminates the singularity at seepage points. By discretizing the PVI formulation, a finite element procedure together with an iterative algorithm was suggested. An existing experiment of unsaturated flow in a layered hillside and a laboratory test of unsaturated flow through sand flume performed in this study were used to validate the proposed method, with a good agreement between the measured and computed results and a satisfactory balance of mass being maintained during the simulations. The numerical results also indicated that the problem of mesh dependence associated with unsaturated flow simulations is well addressed with the proposed numerical method. Finally, the process of unsaturated flow in a soil slope with layers of horizontal drains subjected to rainfall/evaporation was further examined. The numerical results reveal that the deployment of drains in a soil slope can significantly lower the pore water pressure around the drains, with the bottom layer drains being most effective in controlling the seepage flow. [ABSTRACT FROM AUTHOR]

In this paper, atmospheric origins of the widest wildfire in Mazandaran province on 11-13th of December, 2010 have been investigated. Data sets of this research include maximum daily temperature (MDT), minimum relative humidity (MRH) of terrestrial stations, dynamic and thermodynamic features of the atmosphere, Gridded data sets of Self-Calibrated Palmer drought severity index (SCPDSI) and global drought dataset standardized precipitation-evapotranspiration index (SPEI) and data related to the time and the extent of the wildfire. The ''environmental to circulation'' approach to synoptic classification has been used to investigate relationships between local-scale surface environment (wildfire) and the synoptic-scale atmospheric circulation conditions. Results of study show that during the 3-day wide wildfire, the average of MDT and the MRH was significantly different from the long-term average. During the aforementioned wildfire, the average of MDT in Mazandaran province was 26 °C and the average of MRH was reported 35 %. The long-term average of MDT and the MRH in Mazandaran province during 3 days of wildfire was 12.3 °C and 68 %, respectively. Therefore, the MDT has a positive abnormality of 13.7 °C and the MRH has a negative abnormality of 33 %. In addition, monthly SCPDSI and SPEI indicated severe drought conditions at December 2010 in Mazandaran. Analysis of SLP maps shows that during the 3-day fire, a pressure center of 1110 hPa on Persian Gulf and a very low-pressure center on Turkey and Asia Minor were created. Normally, this event has caused the pressure gradient and warm and dry air advection from Arabian Peninsula to higher longitudes, particularly Mazandaran province. Consequently, the MDT increased and the wildfire of Mazandaran forest took place in an area of 220 ha. Zonal wind maps signify the weakness of Zonal wind and meridional wind maps show the southern direction of meridional wind flow during the wide wildfire. Moreover, Omega maps prove that during the aforementioned wildfire, the Omega flow has been positive and the warm air flow has subsidence. This made the infusion of warm air and increased the MDT substantially and consequently the wildfire occurrence was facilitated. Temperature advection maps showed that in the level of 1000 hPa, the warm air blowing source is originated from Arabian Peninsula, in the level of 850 hPa from the Arabian Peninsula and Iraq and in the level of 700 and 500 hPa from Ethiopia, Arabian Peninsula and Iraq. The Hybrid-Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model outputs confirm the synoptic mechanisms for the discussed wildfire. [ABSTRACT FROM AUTHOR]

The paper proposes a novel physically inspired population-based metaheuristic algorithm for continuous structural optimization called as Water Evaporation Optimization (WEO). WEO mimics the evaporation of a tiny amount of water molecules adhered on a solid surface with different wettability which can be studied by molecular dynamics simulations. A set of six truss design problems from the small to normal scale are considered for evaluating the WEO. The most effective available state-of-the-art metaheuristic optimization methods are used as basis of comparison. The optimization results demonstrate the efficiency and robustness of the WEO and its competitive performance to other algorithms for continuous structural optimization problems. [ABSTRACT FROM AUTHOR]

This paper analyzes the impact of cyclones to the atmospheric components on the Mediterranean Sea Water Budget, namely the cyclones contribution to precipitation and evaporation over the Mediterranean Sea. Three regional simulations were performed with the WRF model for the period 1989-2008. The model was run (1) as a standalone model, (2) coupled with the oceanic model NEMO-MED12 and (3) forced by the smoothed Sea Surface Temperature (SST) fields from the second simulation. Cyclones were tracked in all simulations, and their contribution to the total rainfall and evaporation was quantified. Results show that cyclones are mainly associated with extreme precipitation, representing more than 50 % of the annual rainfall over the Mediterranean Sea. On the other hand, we found that cyclone-induced evaporation represents only a small fraction of the annual total, except in winter, when the most intense Mediterranean cyclones take place. Despite the significant contribution of cyclones to rainfall, our results show that there is a balance between cyclone-induced rainfall and evaporation, suggesting a weak net impact of cyclones on the Mediterranean Sea water budget. The sensitivity of our results with respect to rapid SST changes during the development of cyclones was also investigated. Both rainfall and evaporation are affected in correlation with the SST response to the atmosphere. In fact, air feedbacks to the Mediterranean Sea during the cyclones occurrence were shown to cool down the SST and consequently to reduce rainfall and evaporation at the proximity of cyclone centers. [ABSTRACT FROM AUTHOR]

Recent progresses on nanocapillary-driven water transport under metastable conditions have substantiated the potential of artificial trees for dewatering applications in a wide pressure range. This paper presents a comprehensive performance analysis of artificial trees encompassing the principle for negative capillary pressure generation; impacts of structural, compositional, and environmental conditions on dewatering performance; and design considerations. It begins by delineating functionalities of artificial trees for evaporation (leaves), conduction (xylem), and filtration (root) of water, in the analogy to natural trees. The analysis revealed that the magnitude of (negative) capillary pressure in the artificial leaves and xylem must be sufficiently large to overcome the osmotic pressure of feed at the root. The required magnitude can be reduced by increasing the osmotic pressure in the artificial xylem conduits, which reduces the risk of cavitation and subsequent blockage of water transport. However, a severe concentration polarization that can occur in long xylem conduits would negate such compensation effect of xylem osmotic pressure, leading to vapor pressure depression at the artificial leaves and therefore reduced dewatering rates. Enhanced Taylor dispersions by increasing xylem conduit diameters are found to alleviate the concentration polarization, allowing for water flux enhancement directly by increasing leaf-to-root membrane area ratio. [ABSTRACT FROM AUTHOR]

This paper introduces a reservoir design optimization model adapted to incorporate performance norms so that the active storage capacity can be determined assuming that failures may occur during the reservoir operation. The model is able to find the optimal reservoir capacity admitting either a predefined minimum number of failure periods or a maximum failure magnitude, or both. It is formulated as a mixed integer linear program that properly manages reservoir spills and includes evaporation losses. The procedure performs effectively for an example problem and Monte Carlo simulations and shows that lower accepted reliabilities and higher accepted vulnerabilities require less active storage. [ABSTRACT FROM AUTHOR]

Gravity desalination is an important method for obtaining fresh water from sea ice; however, the large amount of ice that is exposed to air for long periods of time sublimates and evaporates, which results in a reduction of the freshwater resource. This paper describes a study of sea ice sublimation and evaporation performed during the winter of 2013 at the western shore of Bohai Bay, China, to determine the relationship between the amount of sublimation and evaporation and the atmospheric parameters. Substantial amounts of the Bohai sea ice sublimated and evaporated, ranging from 15 to 35 % of the total. The sublimation and evaporation amount was significantly different between the day and night and was greater in the daytime because of the relative humidity difference. Sublimation and evaporation is primarily affected by atmospheric parameters, and the amount of sublimation and evaporation exhibits a good linear relationship with the relative humidity and the wind speed; a comprehensive parameters formula was determined for the Bohai Rim in China. A 10 % increase of daily relative humidity will reduce approximately 1.5 kg/m/day of the sublimation and evaporation, and the amount of sublimation and evaporation increases by 1.76 kg/m/day when the daily wind speed increases by 1 m/s. To reduce the sublimation and evaporation and maximize the amount of this freshwater resource, gravity desalination sites should be selected where the wind speed is low and the relative humidity is high, i.e., the sea ice should be configured to reduce the adverse effects of sunlight, low humidity, and air turbulence. [ABSTRACT FROM AUTHOR]

It is of great significance for the efficient utilization of water resources and the construction of the ecological environment in China to fully understand the evolution process of the spatial-temporal pattern of evapotranspiration (ET). With the use of the v2.0 and v2.1 ET data sets combined with the Global Land Data Assimilation System and Noah model, this paper selects pixels as the basic research object to analyse the spatial-temporal variation in ET in China during the 71 years from 1948 to 2018. We first applied the TFPW-MK test to study the annual ET trend in China throughout the 71-year period, including the ET trend of each month from January to December and the annual total ET trend. Moreover, we examined the spatial variation in these trends. In addition, we calculated the variation coefficient of the time series of each pixel's ET throughout the 71-year period and the variation coefficient of the spatial distribution of ET in each year to analyse the spatial-temporal fluctuations in ET in the study area. Finally, the Hurst index was adopted to evaluate the future ET trend. Based on these analyses, we observed the following novel spatial-temporal characteristics of ET: from 1948 to 2018, (1) the ET in most regions covered by 89.5% of all pixels in China exhibits an increasing trend. (2) The ET trend in China varies greatly with the change in months, and many regions show the most or least obvious increasing trend (or decreasing trend) at different times. (3) The area with an increasing trend is the largest in May and the smallest in December, and more than half of the pixels in all months of a year reveal an increasing trend. (4) In the northeast, west and south regions of China, the monthly fluctuation in the ET trend is relatively large, which indicates that the ET trend in these regions is greatly affected by the month. (5) The fluctuation in ET in China is larger in the north than it is in the south and larger in the west than it is in the east. The most stable fluctuation occurs in East China. (6) The ET trend of almost all the pixels in the study area remains consistent from 1948 to 2018, and there are large areas with a notable continuity. This results in the spatial variation in ET in the study area increasing. [ABSTRACT FROM AUTHOR]

Fog on the automotive windshield interferes with the sight of the driver and causes serious safety problems; thus, removing it rapidly has been a longstanding goal in the automobile industry. In this study, we propose a novel method for improving the defogging performance of the defroster without its structural alteration by using vortex generators (VGs). To optimize the performance of the VGs, we performed particle image velocimetry experiments, an evaporation measurement experiment, and a numerical simulation for visualizing the airflow from the defroster inlet. The dimensions of the VG (height h = δ and length ℓ = 5δ) were selected according to the boundary-layer thickness, δ, of the lowest-flow rate (ulow = 0.33 m/s) used in the defroster inlet. We employed a dimensionless parameter, i.e., the secondary flow intensity (Se), to quantify the intensity of vortices for several angles of attack (30°, 45°, and 60°). The results indicated that the vortices generated from VGs with a 30° angle of attack retained their maximum intensity until they reached the vision area of the driver. Additionally, we explored two different configurations of VGs—co-rotating and counter-rotating—and concluded that the counter-rotating configuration had higher performance than the co-rotating configuration. The optimized VGs were directly inserted in the defroster inlet and improved the defogging performance by approximately 10%. The proposed method is applicable to various automobile models for enhancing the performance of the defroster regardless of the interior volume, air-ventilation performance, and other conditions, such as the number of passengers and outside temperature. [ABSTRACT FROM AUTHOR]

This article presents an innovative study to enhance the accuracy of lubrication oil evaporation measurement from the oil film through thermal and sensitivity analyses. The study employs a novel experimental configuration to examine the influence of temperature variations and oil film thickness on oil evaporation. The oil film's temperature is investigated comprehensively, applying experimental and theoretical approaches through different conditions. In order to enhance the accuracy of oil film temperature estimation, the study suggests introducing a correction factor accounting for the thermal properties of vapor during the multiphase liquid evaporation process. The findings indicate that small changes in the thickness of the oil film have no discernible effect on its temperature. In contrast, the evaporation characteristics of the oil film are notably influenced by the properties of its liquid and vapor phases. Incorporating the proposed correction factor (0.84) enhances the accuracy of the oil film temperature estimation equation. The findings presented in this study hold significant value for improving the accuracy of modeling considerations for the optimal configuration of piston rings in internal combustion engines. [ABSTRACT FROM AUTHOR]

Marine and atmospheric parameters, including temperature observations from surface to 80 m (at 6 depths) are measured since September 1973 on a higher-than-weekly frequency, at a coastal station 4 km offshore L'Estartit (Costa Brava; NW Mediterranean). This constitutes the longest available uninterrupted oceanographic time series in the Mediterranean Sea. The present contribution focuses on observed climatic trends in temperature (°C/year) of air (AT; 0.05), sea surface (SST; 0.03), sea at 80 m depth (S80T; 0.02) and sea level (SL; 3.1 mm/year) as well as comparison with trends estimated from coincident high-resolution satellite data. The trending evolution is not uniform across seasons, being significantly higher in spring for both AT and SST, while in autumn for S80T. Other climatological results are a stratification increase (0.02 °C/year in summer temperature difference between 20 m (S20T) and S80T), trends in summer conditions at sea (when S20T > 18 °C), estimated as 0.5 and 0.9 days/year for the starting day and period respectively, and a decreasing trend of nearly 2 days/year in the period of conditions favourable for marine evaporation (when AT < SST). This last trend may be related to the observed decrease of coastal precipitation in spring. The long-term consistency in the in situ SST measurements presents an opportunity to validate the multi-decadal trends. The good agreement for 2013–2018 (RMS 0.5–0.6, bias − 0.1 to − 0.2; trends of 0.09 °C/year in situ vs. 0.06 to 0.08 °C/year from satellite) allows considering this observational site as ground truth for satellite observations and a monitoring site for climate change. [ABSTRACT FROM AUTHOR]

Extending previous work on the formation and the evaporation of black holes in conformal gravity, in the present paper we study the gravitational collapse of a spherically symmetric and electrically charged thin shell of radiation. The process creates a singularity-free black hole. Assuming that in the evaporation process the charge Q is constant, the final product of the evaporation is an extremal remnant with M=Q, which is reached in an infinite amount of time. We also discuss the issue of singularity and thermodynamics of black holes in Weyl’s conformal gravity. [ABSTRACT FROM AUTHOR]

Terrestrial open water evaporation is difficult to measure both in situ and remotely yet is critical for understanding changes in reservoirs, lakes, and inland seas from human management and climatically altered hydrological cycling. Multiple satellite missions and data systems (e.g., ECOSTRESS, OpenET) now operationally produce evapotranspiration (ET), but the open water evaporation data produced over millions of water bodies are algorithmically produced differently than the main ET data and are often overlooked in evaluation. Here, we evaluated the open water evaporation algorithm, AquaSEBS, used by ECOSTRESS and OpenET against 19 in situ open water evaporation sites from around the world using MODIS and Landsat data, making this one of the largest open water evaporation validations to date. Overall, our remotely sensed open water evaporation retrieval captured some variability and magnitude in the in situ data when controlling for high wind events (instantaneous: r2 = 0.71; bias = 13% of mean; RMSE = 38% of mean). Much of the instantaneous uncertainty was due to high wind events (u > mean daily 7.5 m·s−1) when the open water evaporation process shifts from radiatively-controlled to atmospherically-controlled; not accounting for high wind events decreases instantaneous accuracy significantly (r2 = 0.47; bias = 36% of mean; RMSE = 62% of mean). However, this sensitivity minimizes with temporal integration (e.g., daily RMSE = 1.2–1.5 mm·day−1). To benchmark AquaSEBS, we ran a suite of 11 machine learning models, but found that they did not significantly improve on the process-based formulation of AquaSEBS suggesting that the remaining error is from a combination of the in situ evaporation measurements, forcing data, and/or scaling mismatch; the machine learning models were able to predict error well in and of itself (r2 = 0.74). Our results provide confidence in the remotely sensed open water evaporation data, though not without uncertainty, and a foundation by which current and future missions may build such operational data. [ABSTRACT FROM AUTHOR]

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Reducing water evaporation from the soil surface of the cropland is a way to save irrigation water and improve water efficiency. For the first time, we calculated how much water can be saved at the level of a country by reducing soil evaporation and runoff and whether this reduction has an effect on plant production. To determine the effects of reducing soil water evaporation and runoff on crop productivity a modeling system was implemented. The model setup included 2750 combinations of "plant - production conditions - province" spanning 2000 to 2015 (44,000 simulations for each scenario). There were different combinations of reduced soil water evaporation and reduced runoff included in seven scenarios. Approximately 81.7 billion m3 of water was irrigated annually in Iranian crop production, which markedly decreased with a decrease in soil evaporation. For various species groups, the net irrigation water requirement (NIWR) and the gross irrigation water requirement were calculated. The highest NIWR was observed for oil grains (1403 m3t−1), and the lowest values were obtained for vegetables (111 m3t−1). A proper water management under irrigated systems can save an estimated 8.3 billion m3 of water per year at country level. Water savings of this magnitude is comparable with water consumption in industries and urban areas in Iran. In rainfed systems, water productivity increased under different scenarios of reduced soil water evaporation. This system can be useful in long-term planning of agriculture that is often determined by political decisions made by the nations themselves, not by world politics. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

An effective Lagrangian Planar Interferometric Tracking (PIT) processor is proposed to track the size and path of multiple droplets, with spray droplet diameters (20–150 µm) and volumetric concentrations (≈ 300 drops/cm 3 ) consistent with industrial applications, produced by an ultrasonic atomiser in evaporating conditions. A test facility was developed where liquid droplets are exposed to a temperature gradient in a co-axial air flow, where the outer stream is preheated to the desired temperature (288–550 K). The PIT method builds on a TSI Global Sizing Velocimtery measurement technique and allows to detect, size and follow the path of droplets which were otherwise discarded or mis-analysed by the commercial software. The methodology was first tested under non-evaporating conditions, and multiple sources of errors, some common to most planar interferometric techniques, were identified and their order of magnitude and impact on final droplet measurement assessed. The main source of error is related to the out-of-plane motion of the droplets and the time they spend in the measurement volume. For non-evaporating conditions, measured data can be processed to filter out this source of error. In evaporating conditions, a novel method for assessing the impact of measurement error with respect to droplet evaporation and measurement timescales is defined. The PIT method allowed tracking of individual methanol droplets entrained within an airflow heated to 495 K and determining their size reduction under evaporating conditions. Measured droplet evaporation rates were then compared against those predicted by an iterative evaporation model, and a very good agreement was found between the modelled and measured estimates. [ABSTRACT FROM AUTHOR]

Periodic flooding limits livestock farming on cattle ranches in floodable areas. In order to propose recommendations for sustainable management of these ranches, we examined the relationships between surface water hydrological processes (infiltration and evaporation) and vegetation cover in the Paraguayan Humid Chaco. A total of 24 evaporation and infiltration measurements were made in a gradient of woody vegetation density between the forest and the adjacent grassland, and at different distances from reference trees (from the trunk to outside the tree crown). Soil texture and moisture were also characterized. There was a positive effect of woody vegetation density on infiltration although final infiltration rates in forests (94.5 mm h− 1) were not significantly higher than in grasslands (22.0 mm h− 1) or forest-grassland transition (11.5 mm h− 1). Evaporation was significantly lower in forests (0.0338 mm h− 1) than in grassland (0.1361 mm h− 1) or at the transition zone (0.0868 mm h− 1), reflecting the effects of tree cover on microhabitat features. Infiltration rates decreased with the distance to the tree trunk. These results support our hypothesis that subtropical forests, specifically Schinopsis balansae and Psidium sp., have a positive effect on infiltration, and these forests have a negative effect on surface water evaporation. Introduction of trees at relative low densities in deforested rangelands may help improve hydrological services (i.e., enhance soil infiltrability) and facilitate cattle raising, while promoting local biodiversity. [ABSTRACT FROM AUTHOR]

We developed a 3D solar steam generator with the highest evaporation rate reported so far using a carbonized luffa sponge (CLS). The luffa sponge consisted of entangled fibers with a hierarchically porous structure; macropores between fibers, micro-sized pores in the fiber-thickness direction, and microchannels in the fiber-length direction. This structure remained after carbonization and played an important role in water transport. When the CLS was placed in the water, the microchannels in the fiber-length direction transported water to the top surface of the CLS by capillary action, and the micro-sized pores in the fiber-thickness direction delivered water to the entire fiber surface. The water evaporation rate under 1-sun illumination was 3.7 kg/m2/h, which increased to 14.5 kg/m2/h under 2 m/s wind that corresponded to the highest evaporation rate ever reported under the same condition. The high evaporation performance of the CLS was attributed to its hierarchically porous structure. In addition, it was found that the air temperature dropped by 3.6 °C when the wind passed through the CLS because of the absorption of the latent heat of vaporization. The heat absorbed by the CLS during water evaporation was calculated to be 9.7 kW/m2 under 1-sun illumination and 2 m/s wind, which was 10 times higher than the solar energy irradiated on the same area (1 kW/m2). [ABSTRACT FROM AUTHOR]

Water availability seriously affects vegetation restoration in arid mining areas, and mulching is an effective way to improve soil water conditions. Coal gangue occupies large swathes of land resources, resulting in ecological fragility and various environmental problems. Despite coal gangue having mineral elements similar to those in soil, its potential function as a mulch for soil water conservation has been unclear. Herein, mulching on the surfaces of soil columns with 30 cm height and 15 cm inner diameter was conducted using coal gangue with four particle size ranges (0–0.5, 0.5–1, 1–2, and 2–4 cm) and four thicknesses (4, 8, 12, and 16 cm) under laboratory conditions to investigate water infiltration and evaporation under different conditions. The cumulative infiltration of the treatments with mulching thicknesses of 4 cm (T1), 8 cm (T2), 12 cm (T3), and 16 cm (T4) was 16.1%, 22.9%, 28.6%, and 41.6% greater than that of the control, respectively. The cumulative evaporation of the treatments with particle size ranges of 0–0.5 cm (P1), 0.5–1 cm (P2), 1–2 cm (P3), and 2–4 cm (P4) was 6.5%, 28.6%, 22.9%, and 18.6% lower than the control, respectively. Overall, to enhance the soil water storage capacity in mining areas, the results suggest that coal gangue mulching with a thickness of 8–16 cm and particle size range of 0.5–2 cm is suitable. [ABSTRACT FROM AUTHOR]

Earth observation has traditionally required a compromise in data collection. That is, one could sense the Earth with high spatial resolution occasionally; or with lower spatial fidelity regularly. For many applications, both frequency and detail are required. Precision agriculture is one such example, with sub-10 m spatial, and daily or sub-daily retrieval representing a key goal. Towards this objective, we produced the first cloud-free 3 m daily evaporation product ever retrieved from space, leveraging recently launched nano-satellite constellations to showcase this emerging potential. Focusing on three agricultural fields located in Nebraska, USA, high-resolution crop water use estimates are delivered via CubeSat-based evaporation modeling. Results indicate good model agreement (r2 of 0.86–0.89; mean absolute error between 0.06 and 0.08 mm/h) when evaluated against corrected flux tower data. CubeSat technologies are revolutionizing Earth observation, delivering novel insights and new agricultural informatics that will enhance food and water security efforts, and enable rapid and informed in-field decision making. [ABSTRACT FROM AUTHOR]

Blood pools can spread on several types of substrates depending on the surrounding environment and conditions. Understanding the influence of these parameters on the spreading of blood pools can provide crime scene investigators with useful information. The focus of the present study is on phase separation, that is, when the serum spreads outside the main blood pool. For this purpose, blood pools with constant initial masses on wooden floors that were either varnished or not were created at ambient temperatures of 21 ∘ C , 29 ∘ C , and 37 ∘ C with a relative humidity varying from 20 to 90%. The range 21 ∘ C to 37 ∘ C covers almost all worldwide indoor cases. The same whole blood from the same donor was used for all experiments. As a result, an increase in relative humidity was found to result in an increase in the final pool area. In addition, at the three different experimental temperatures, the serum spread outside the main pool at relative humidity levels above 50%. This phase separation is more significant on varnished substrates, and does not lead to any changes in the drying morphology. This phenomenon is explained by the competition between coagulation and evaporation. [ABSTRACT FROM AUTHOR]

The interannual variability of the sea surface temperature (SST) in the Indian Ocean is complex and characterized by various air-sea coupled modes, which occur around El Niño/La Niña's peak phase (i.e. December–January–February, DJF). Indian Ocean Dipole Mode (IODM) develops over the tropical Indian Ocean and peaks in September–October–November (SON), while Ningaloo Niño, Subtropical Indian Ocean Dipole (SIOD) and Indian Ocean Basin Mode (IOBM) occur respectively over northwest off Australia, subtropical and tropical Indian Ocean, during boreal winter to spring. The apparent contrast between their divergent regionality and convergent seasonality around DJF triggers the present study to examine the interaction between the local mean monsoonal cycle and the anomalous forcing from El Niño/La Niña. The diagnosis confirms that the Indian Ocean's unique complexity, including the monsoonal circulation over the tropics and the trade wind over the subtropical southern Indian Ocean, plays the fundamental role in anchoring the various regional air-sea coupled modes across the basin. The SST anomalies can be readily explained by the wind-evaporation-SST (WES) mechanism, which works together with other more regional-dependent dynamic and thermodynamic mechanisms. This implies that El Niño/La Niña brings much predictability for the Indian Ocean variations. [ABSTRACT FROM AUTHOR]

Soil moisture content is a key factor affecting surface evaporation in the hydrologic cycle, with application in water resources management, early drought warning system, irrigation management, and estimation of crop yield. The subject of soil moisture content has long been of interest in hydrology, agriculture, forestry, and soil mechanics engineering. The cracking of surface soil due to dryness is often used to describe the drought condition of the land based on the certain relationship between soil cracking and moisture content. This study establishes the relation between fractal dimensions of soil cracking patterns and moisture content of surface soil. Sixteen soil samples were prepared and subjected to drying under different temperature levels to crack in the laboratory. Photographs of the cracks were digitized and an algorithm for calculating fractal dimensions of cracking patterns was developed. The results demonstrated that the fractal dimensions of cracking patterns are highly correlated with the surface soil moisture content; the lower the soil moisture content, the larger the fractal dimension is. Therefore, the surface soil moisture content–fractal dimension (DB-w) rating curves can be established. Once crack structures occur on surface soil, the moisture content of the surface soil can be estimated quickly and accurately by mean of remote sensing technique such as UAV together with the fractal analysis. [ABSTRACT FROM AUTHOR]

The precipitation that falls on the continents defines the extent and nature of terrestrial ecosystems and human activity in them, all of which are adapted to and maintained by present-day precipitation. In essence, precipitation is supplied by moisture that either comes directly from the ocean, or is subsequently recycled from the continents themselves. Both the processes that control evaporation and the main mechanisms of moisture transport clearly differ between the ocean and the continent, thus within the context of a changing climate, it may be expected that the relationship between precipitation of oceanic and terrestrial origin varies globally and regionally, as will the influence of these two basic components of total precipitation on global and regional precipitation trends, especially in tropical regions. We describe an approach based on a Lagrangian technique for estimating the precipitation in a target region given the proportions of moisture transported from the two sources (ocean and continent) to reveal that the percentage of precipitation of oceanic origin has increased globally in the current climate (1980–2016). The greatest observed rate of increase is in the tropical regions; furthermore, the trends of precipitation in these regions are controlled by trends in precipitation for which the source of moisture is the ocean. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) is rapidly gaining popularity as a result of the advancements in portable embedded devices and wireless protocols, enabling a new class of services. On the other hand, edge clouds provide IoT services as a new paradigm called fog computing. As the number of available IoT devices increases, more efficient methods are required to select the optimal combination of services out of several existing candidates in edge clouds while composing more complex IoT workflow tasks. So, cloud-assisted fog computing requires a platform for management, composition and provisioning of IoT services for IoT–cloud integration. Resent works have some weaknesses and did not consider some aspects of fog computing such as low latency, low energy and efficient resource allocation. We propose a cloud-based platform for management of IoT service selection and composition in fog computing to enhance QoS parameters such as bandwidth usage, latency and distributed resource utilization. In particular, we propose a multi-objective evolutionary game theory, enhanced by evaporation-based water cycle algorithm (EG-ERWCA) to optimize CPU usage, power consumption and latency of the IoT workflows in cloud-assisted fog computing environments. Many different real IoT workflows are used for evaluation of the proposed method in comparison with the state-of-art algorithms. Simulation results show that the overall quality of service is improved by 2.66 times compared to rival algorithms. [ABSTRACT FROM AUTHOR]

Both seasonal and annual mean precipitation and evaporation influence patterns of water availability impacting society and ecosystems. Existing global climate studies rarely consider such patterns from non-parametric statistical standpoint. Here, we employ a non-parametric analysis framework to analyze seasonal hydroclimatic regimes by classifying global land regions into nine regimes using late 20th century precipitation means and seasonality. These regimes are used to assess implications for water availability due to concomitant changes in mean and seasonal precipitation and evaporation changes using CMIP5 model future climate projections. Out of 9 regimes, 4 show increased precipitation variation, while 5 show decreased evaporation variation coupled with increasing mean precipitation and evaporation. Increases in projected seasonal precipitation variation in already highly variable precipitation regimes gives rise to a pattern of "seasonally variable regimes becoming more variable". Regimes with low seasonality in precipitation, instead, experience increased wet season precipitation. Adequate water availability is key to human and ecosystem sustainability. Here, the authors show that seasonally variable regimes become more variable, and the combined influence of seasonality and magnitude of climate variables will affect future water availability. [ABSTRACT FROM AUTHOR]

Precise measurement or estimation of evaporation losses is extremely important for the development of water resource management strategies and its effective implementation, particularly in drought-prone areas for increasing agricultural productivity. Evaporation can either be measured directly using evaporimeters, or it can be estimated by means of empirical models with the help of climatic factors influencing evaporation process. In general, variations in climatic factors such as temperature, humidity, wind speed, sunshine and solar radiation influence and control the evaporation process to a great extent. Due to the highly nonlinear nature of evaporation phenomenon, it is invariably very difficult to model the evaporation process through climatic factors especially in diverse agro-climatic situations. The present investigation is carried out to examine the potential of deep neural network architecture with long short-term memory cell (Deep-LSTM) to estimate daily pan evaporation with minimum input features. Depending upon the availability of climatic data Deep-LSTM models with different input combinations are proposed to model daily evaporation losses in three agro-climatic zones of Chhattisgarh state in east-central India. The performance of the proposed Deep-LSTM models are compared with commonly used multilayer artificial neural network and empirical methods (Hargreaves and Blaney–Criddle). The results of the investigations in terms of various performance evaluation criteria reveal that the proposed Deep-LSTM structure is able to successfully model the daily evaporation losses with improved accuracy as compared to other models considered in this study. [ABSTRACT FROM AUTHOR]

Accurate evaluation of habitat availability for wildlife is relevant for ecological applications. Researchers have frequently used models to simulate habitats thermally suitable for reptiles, but these results have limited application for species highly selective for habitat humidity. Here, we use the biophysical Niche Mapper™ model to investigate impacts of vegetation cover on the habitat quality of a high-elevation forest skink, Sphenomorphus taiwanensis, and to predict changes in habitat suitability in a future warmer climate (3 °C increase in air temperature). We assess habitat suitability with different densities of canopy cover in our study areas using two ecologically relevant estimates for lizards: maximum activity time and evaporative water loss (EWL) during the activity season. We measured preferred body temperature and EWL of this species for model parameterization, and behavioral response to EWL to supplement habitat quality assessment. The results indicated that this species is sensitive to EWL and reduces its activity when dehydrated. The model predicted that denser canopy levels increase microclimate cooling and humidity, and that most canopy levels are thermally suitable for this species, as the lizard can thermoregulate to manage adverse temperatures. Nevertheless, increasing canopy density could significantly decrease EWL during activity. In the warmer climate scenario, simulated maximum activity time and EWL changed little because of thermoregulation behavior. Our results suggest that habitat preference of this species is a consequence of water and energy requirements, and we note that combining EWL and maximum activity time data can enhance model accuracy of lizards' habitat quality in a warmer climate. [ABSTRACT FROM AUTHOR]

The design of water resource structures needs long-term runoff data which is always a problem in developing countries due to the involvement of huge cost of operation and maintenance of gauge discharge sites. Hydrological modelling provides a solution to this problem by developing relationship between different hydrological processes. In the past, several models have been propagated to model runoff using simple empirical relationships between rainfall and runoff to complex physical model using spatially distributed information and time series data of climatic variables. In the present study, an attempt has been made to compare two conceptual models including TANK and Australian water balance model (AWBM) and a physically distributed but lumped on HRUs scale SWAT model for Tandula basin of Chhattisgarh (India). The daily data of reservoirs levels, evaporation, seepage and releases were used in a water balance model to compute runoff from the catchment for the period of 24 years from 1991 to 2014. The rainfall runoff library (RRL) tool was used to set up TANK model and AWBM using auto and genetic algorithm, respectively, and SWAT model with SWATCUP application using sequential uncertainty fitting as optimization techniques. Several tests for goodness of fit have been applied to compare the performance of conceptual and semi-distributed physical models. The analysis suggested that TANK model of RRL performed most appropriately among all the models applied in the analysis; however, SWAT model having spatial and climatic data can be used for impact assessment of change due to climate and land use in the basin. [ABSTRACT FROM AUTHOR]

As many Mediterranean headwater catchments, the Moroccan Middle Atlas plays an important role in the highly vulnerable regional water resources. Mountain lakes are numerous in this region, and could be regarded as possible sentinels of hydro-climatic changes, using appropriate modelling tools able to simulate the lake-climate relation. We present a detailed study of Lake Azigza, based on a 4-year (2012–2016) observation period, including lake level measurements, isotope analyses of precipitation, lake and spring waters, and local meteorological data. The approach is based on a calibration of a daily time-step lake water and isotope mass balance model, fed by precipitation and evaporation rates, to estimate the ungauged components of the water balance. Results show the dominance of groundwater exchanges in the lake water balance, with significant interannual variations related to annual precipitation. At the annual time-step, groundwater inflow varies between twice and up to six times the amount of direct precipitation, while the groundwater loss reached up to five times evaporation. However, a significant decrease of groundwater loss is observed in 2016, suggesting that a threshold effect probably limits the seepage when the lake level decreases. This study underlines the importance of groundwater fluxes in the lake level variations for Lake Azigza, probably representative of many similar lakes in the Middle Atlas. The model was able to simulate the continuous lake level decrease (4 m) observed over 2012–2016 and can be further used to explore lake-climate relations at different timescales. [ABSTRACT FROM AUTHOR]

Advance knowledge of solar radiation is highly essential for multiple energy devotions such as sustainability in energy production and development of solar energy system. The current research investigates the capability of four data mining computation models, namely random forest (RF), random tree, reduced error pruning trees and hybrid model of random committee with random tree reduce (RC) for predicting daily measured solar radiation at four locations of Burkina Faso, i.e., Bur Dedougou, Bobo-Dioulasso, Fada-Ngourma and Ouahigouya. Daily data of seven climatic variables, namely maximum and minimum air temperature, maximum and minimum relative humidity, wind speed, evaporation and vapor pressure deficit, for the period 1998–2012 are used for solar radiation prediction. Different combinations of input variables are used according to correlation coefficient between the predictors and predictand, and the best input combination is selected based on the sensitivity of model output measured in terms of statistical indices. The obtained results are found consistence for all the meteorological stations. The highest accuracy in prediction is found when all the climate variables are used as input. The RC and RF showed the minimal absolute error in prediction at all the stations. The RMSE and NSE are found in the range of 0.03–0.05 and 0.77–0.91 for RC and 0.03–0.05 and 0.78–0.92 for RF at different stations. The results indicate that the proposed data mining models can be used for accurate prediction of solar radiation over the Burkina Faso. [ABSTRACT FROM AUTHOR]

Northeast Brazil's semiarid region is characterized by water deficit. However, little is known about the trends in joint water loss by evaporation and transpiration (evapotranspiration) in the region. Thus, this study aimed to analyze indications on the linear trend of reference evapotranspiration (ET0) in the monthly, annual, and interdecadal scales in irrigated agricultural areas in the microregions of Juazeiro, Bahia State (9° 24' S; 40° 26' W and 375.5 m), and Petrolina, Pernambuco State (09° 09' S, 40° 22' W, and 376 m). For this purpose, we used a set of daily meteorological data, collected from January 1, 1976, to December 31, 2014. Daily ET0 values were estimated by the FAO's Penman-Monteith equation (ET0PM). The main statistical tests used were the nonparametric Mann-Kendall test, the Sen test to detect the magnitude of the trend, and the Pettitt test to detect the start of the trend. For all tests, statistical significance was 5% and/or 1%. Analysis of variance (ANOVA) was also applied to identify significant differences between the mean interdecadal values for each season. The results showed a significant decreasing trend for ET0 in both Juazeiro (α = 5%) and Petrolina (α = 1%), with declines of 14.5 mm/year (Juazeiro) and 7.7 mm/year (Petrolina) and that this trend started in 1996. Probably, the ET0 decrease was associated with the increase in the irrigated agricultural areas, and the lake formed upstream from the areas by the construction of Sobradinho Dam. [ABSTRACT FROM AUTHOR]

As a UNESCO biosphere, Lake Urmia is a shallow hypersaline lake which is facing a rapid water surface degradation. Evaporation from the surface of the Lake, as a physical process which accelerates the Lake's degradation, was evaluated using chaos theory. Seven hydrometeorological stations scattered around the Lake were selected, and a 40-year time span between October 1974 and September 2014 was used at each station. Missing data in time series was removed and the whole time series was tested for consistency, randomness, and presence of trend. Since evaporation at each station was measured by means of class A evaporation pan, time series at each station was multiplied by a pan coefficient to incorporate the effect of saline water and free water surface environment simultaneously. Measurement errors arising from assumption of zero evaporation in winter were removed from the time series using locally weighted scatterplot smoothing method after which unification of time series into a single time series is achieved. Results of the data transformation and information loss were monitored by means of auto-correlation, partial-auto-correlation, mutual information, power spectrum, false nearest neighbor, and correlation dimension. A local prediction method is then used to capture the temporal dynamics of the evaporation with consideration of an appropriate time delay and embedding dimension. Finally, the representative model was projected on a 3-dimensional phase space to evaluate the temporal dynamics of the evaporation. Results indicate that the chaotic approach shows accurate predictions in advance. [ABSTRACT FROM AUTHOR]

After the decadal change being marked by a distinct transition from a downward trend to an upward trend around 1977–1978, the global oceanic evaporation is found to present a regime shift to downward trend from 2000 onwards by using the Objectively Analyzed air-sea Fluxes (OAFlux) dataset. The robustness of post-2000 decreasing trend of global oceanic evaporation featured by OAFlux is fairly confirmed by checking the total precipitation trend from the Global Precipitation Climatology Project (GPCP) and the CPC Merged Analysis of Precipitation (CMAP) datasets via budget constraint. Analysis on the 1999/2000 trend reversal in global mean temporal evolution and local linear trend patterns of evaporation and related variables is performed. Results show that the positive trend of evaporation before 2000 is primarily associated with both the SST warming and the strengthening of near-surface wind, while the negative trend of evaporation after 2000 may be highly correlated with the weakening of near-surface wind speed and reduction in sea-air humidity difference. The post-2000 decreasing of oceanic evaporation mainly effects precipitation trend over oceans via budget constraint, while land precipitation shows no significant decreasing trend, which may be explained by the increasing of evapotranspiration over land. [ABSTRACT FROM AUTHOR]

To quantify lake evaporation and its variations in time, ten methods for estimating evaporation at a temporal resolution of 10 days over a small high-elevation lake in the Nam Co lake basin of the Tibetan Plateau (TP) were evaluated by using eddy covariance (EC) observation-based reference datasets. After examination of the consistency of the parameters used in the different methods, the ranking of the methods under different conditions are shown to be inconsistent. The Bowen ratios derived from meteorological data and EC observations are consistent, and it supports a ranking of energy-budget-based methods (including the Bowen ratio energy budget, Penman, Priestley-Taylor, Brutsaert-Stricker and DeBruin-Keijman methods) as the best when heat storage in the water can be estimated accurately. The elevation-dependent psychometric constant can explain the differences between the Priestley-Taylor and DeBruin-Keijman methods. The Dalton-type methods (Dalton and Ryan-Harleman methods) and radiation-based method (Jensen-Haise) all improve significantly after parameter optimization, with better performance by the former than the latter. The deBruin method yields the largest error due to the poor relationship between evaporation and the drying power of the air. The good performance of the Makkink method, with no significant differences before and after optimization, indicates the importance of solar radiation and air temperature in estimation of lake evaporation. The Makkink method was used for long-term evaporation estimation due to lack of water temperature observations in lakes on the TP. Lastly, long-term evaporation during the open-water period (April 6 to November 15 from 1979 to 2015) were obtained; the mean bias was only 6%. A decreasing-increasing trend in lake evaporation with a turning point in 2004 was noted, and this trend corresponds to the published decreasing-increasing trend in reference evapotranspiration on the Tibetan Plateau and can be explained by variations in related meteorological variables. [ABSTRACT FROM AUTHOR]

Emission of greenhouse gases is being alleged to be causing climate change in different regions of the world. The objective of this study was to analyze the spatio-temporal trends of monthly evaporation at 52 weather stations in the state of Aguascalientes (Mexico) which have hydrometeorological records of long periods. The autocorrelation was eliminated with an auto-regressive model, and the trend was determined using the Spearman (S) and Kendall (K) tests. The statistical significance of the trend was determined with the Spearman correlation coefficient (rs) and the Z statistic (the test statistic of the normal distribution) both indicated that that there were statistically significant trends in 107 time series, of these 88 series had negative trends and 19 series had positive trends. Negative trends were present in all months of the year, while positive trends occurred from February to May and from October to December only. The reduction of evaporation from − 4.10 to − 20.50 mm/month/year from June to September showed a hopeful future scenario for rainfed agriculture. Irrigated agriculture during dry months could have a reduction of irrigation requirements as a consequence of the reduction in reference and crop evapotranspiration. The evaporation increase during dry months could increase irrigation requirements and pumping, mainly in March, April, and November when there are trends with increases of about 26.90, 24.60, and 23.90 mm/month/year, respectively. The spatial variability of evaporation trend means that other effects of climate change could vary in different parts of the state. Results of this study will be useful for farmers and institutions in charge of the administration of water resources for developing adaptation and mitigation strategies to climate change. [ABSTRACT FROM AUTHOR]