Surface Layer Temperature Research Articles

English

Djumanto, Rasul E, InoueT, Aoki S. 2017. Phytoplankton distribution in Mikawa Bay of Japan in relation to temperature and salinity variables.Bonorowo Wetlands 1: 16-25. Species composition and horizontal distribution of phytoplankton in relation to temperature and salinity variables were investigated in Mikawa Bay of Japan. Surface seawater was filtered with a 30 cm diameter conical plankton net with a mesh size of 53 µm weekly from mid-August to late September 2011. Surface layer temperature and salinity were measured with a CTD sensor. Phytoplankton samples were observed with an inverted microscope with phase contrast at 100-400 magnification. The salinity and surface temperature data, as well as the density of the phytoplankton horizontally, were made contour maps by connecting the location of each sampling station having the same value. Contour maps were created using surfer software. The result showed that the average of temperature at the 1 m surface layer was ranged from 22.7 to 28.7 oC. Meanwhile, salinity was ranged from 11.8 psu to 30.0 psu. Phytoplankton was abundant in the area with the high temperature and low salinity. The most abundant species among station of sampling in Bacillariophyceae was Chaetoceros sp(p). (52.2%) followed by Pseudo-Nitzschia sp(p) (27,7%), and then Coscinodiscus sp(p). (6.3%). On the other hand, the most abundant in Dinophyceae was Dinophysis sp(p). (1.1%) followed by Ceratium fusus (0.9%), and then Ceratium furca (0.8%) which was mostly dominant in off river mouth area. The density center and contour lines of phytoplankton population were changed and moved depending on salinity or temperature profiles.

A neighbourhood-scale estimate for the cooling potential of green roofs

Green roofs offer the possibility to mitigate multiple environmental issues in an urban environment. A common benefit attributed to green roofs is the temperature reduction through evaporation. This study focuses on evaluating the effect that evaporative cooling has on outdoor air temperatures in an urban environment. An established urban energy balance model was modified to quantify the cooling potential of green roofs and study the scalability of this mitigation strategy. Simulations were performed for different climates and urban geometries, with varying soil moisture content, green roof fraction and urban surface layer thickness. All simulations show a linear relationship between surface layer temperature reduction ΔTs and domain averaged evaporation rates from vegetation mmW, i.e. ΔTs=eW ⋅ mmW, where eW is the evaporative cooling potential with a value of ∼−0.35 Kdaymm−1. This relationship is independent of the method by which water is supplied. We also derive a simple algebraic relation for eW using a Taylor series expansion.

On the numerical stability of surface–atmosphere coupling in weather and climate models

Abstract. Coupling the atmosphere with the underlying surface presents numerical stability challenges in cost-effective model integrations used for operational weather prediction or climate simulations. These are due to the choice of large integration time steps compared to the physical timescale of the problem, aiming at reducing computational burden, and to an explicit flux coupling formulation, often preferred for its simplicity and modularity. Atmospheric models therefore use the surface-layer temperatures (representative of the uppermost soil, snow, ice, water, etc.) at the previous integration time step in all surface–atmosphere heat-flux calculations and prescribe fluxes to be used in the surface model integrations. Although both models may use implicit formulations for the time steps, the explicit flux coupling can still lead to instabilities.In this study, idealized simulations with a fully coupled implicit system are performed to derive an empirical relation between surface heat flux and surface temperature at the new time level. Such a relation mimics the fully implicit formulation by allowing one to estimate the surface temperature at the new time level without solving the surface heat diffusion problem. It is based on similarity reasoning and applies to any medium with constant heat diffusion and heat capacity parameters. The advantage is that modularity of the code is maintained and that the heat flux can be computed in the atmospheric model in such a way that instabilities in the snow or ice code are avoided. Applicability to snow–ice–soil models with variable density is discussed, and the loss of accuracy turns out to be small. A formal stability analysis confirms that the parametrized implicit-flux coupling is unconditionally stable.

Influence of thermal properties and temperature of substrate on the quality of cold-sprayed deposits

The properties of cold-sprayed deposits are often considered to depend mainly on the particle velocity and the particle temperature. The present paper demonstrates, through systematic experimentation and multi-scale modelling, that the substrate properties, too, influence the deposit properties, even in the regions far away from the substrate/deposit interface. Cold spraying experiments were performed with copper and titanium powders, using fixed process parameters, but different substrate materials and different substrate temperatures. As a measure of coating quality, the electrical conductivity of the coatings was evaluated on the top surface of (0.8–1 mm) thick coatings. The coating conductivity was found to depend strongly on the initial temperature and the thermal effusivity of the substrate. The mechanical properties of the substrate, also, influence the local coating properties, but only in the regions within 50 μm distance from the substrate/coating interface. The temperature and the thermal effusivity of the substrate control the instantaneous temperature of the top surface layer of the already deposited material, thus influencing the extent of particle bonding and the coating properties. These findings underline the role of thermal management in cold spraying.

欧亚波列与京津冀雾霾的关系及形成机制

利用NCEP/NCAR再分析资料和京津冀雾霾资料，采用聚类分析等统计方法对京津冀雾霾异常年环流场进行了分类，发现导致1月京津冀雾霾异常的欧亚大陆500 hPa环流场主要是两个模态的波列分布，方差贡献为0.9。重点讨论了两个模态欧亚波列分布及对应京津冀雾霾异常的形成机制，表明极地近地面层的温度特征决定了中高纬度大气的环流特征。当极区气温偏低时，极涡偏强，欧亚大陆形成东-西向“正、负、正”距平波列，京津冀雾霾天气偏多；反之，则偏少。当格陵兰海到巴伦支海区域气温偏高时，欧亚大陆为西北—东南向“正、负、正”距平波列，京津冀雾霾天气偏多；反之，则偏少。 Based on the NCEP/NCAR Reanalysis data and the haze data of Beijing-Tianjin-Hebei (BTH) re-gion, the circulation of haze abnormal years over the Beijing-Tianjin-Hebei region is classified by cluster analysis and other statistical methods. The results show that two mainly modes of wave trains distribution over Eurasia at 500 hPa circulation field will result in haze abnormal of Beijing-Tianjin-Hebei region in January. Their variance contribution reaches 0.9. This study fo-cuses on two modes of Eurasian wave trains distribution and the formation mechanism of haze over the Beijing-Tianjin-Hebei region; it shows that the characteristics of the polar atmospheric surface layer temperature determine that of the mid-high latitude atmosphere circulation. When the polar surface layer temperature is on the low side, the polar vortex is strong, there will be a “+ − +” anomaly distribution from west to east over the Eurasian continent, the haze weather over the Beijing-Tianjin-Hebei region will be more, and vice versa; When the temperature from the Greenland Sea to the Barents Sea region is on the high side, there will be a “+ − +” anomaly distribution from northwest to southeast over the Eurasian continent, the haze weather over the Beijing-Tianjin-Hebei region will be more, and vice versa.

Pneumatic device of the preload and dynamic loads balancing to reduce the intensity of thermal processes in the metal cutting process

Improved reliability of the technological system «machine-tool-instrument-detail» is an important current task. Backlashes and insufficient stiffness of technological system lead to intensive wear of the cutting tool, increasing the heat in the cutting zone. Due to high temperature in the thin surface layers of the workpiece and tool thermal processes may occur which are similar to release and can cause the structural changes of the material. The current article presents the final design of the device which has been developed to reduce the intensity of thermal processes in metal cutting.

A plausible reason for changes in El Niño parameters in the 2000s

An attempt is made to find a plausible reason for the weakening of the interrelation between the variability in wind and water volume in the tropical warm pool in the western equatorial Pacific and the onset of El Nino–Southern Oscillation event (ENSO). It is demonstrated that variability in the atmospheric dynamics near the Drake Passage can affect the ENSO development. The weakening of the interrelation between ENSO and the variability in wind together with water volume in the tropical warm pool is caused by the fact that the processes of atmosphere–ocean interaction in the tropical Pacific started exerting smaller influence on the ENSO development (as compared with the processes in the Southern Ocean). This is due to warmer ocean conditions registered since the late 1990s that favored the decrease in the zonal gradient of temperature in the ocean surface layer in the tropics and led to lower atmospheric variability in the tropical Pacific whereas this variability remained the same over the Southern Ocean.

Development and study of a parallel algorithm of iteratively forming latent functionally-determined structures for classification and analysis of meteorological data

This paper overviews a method of generating climate regions based on an analytic signal theory. When applied to atmospheric surface layer temperature data sets, the method allows forming climatic structures with the corresponding changes in the temperature to make conclusions on the uniformity of climate in an area and to trace the climate changes in time by analyzing the type group shifts. The algorithm is based on the fact that the frequency spectrum of the thermal oscillation process is narrow-banded and has only one mode for most weather stations. This allows using the analytic signal theory, causality conditions and introducing an oscillation phase. The annual component of the phase, being a linear function, was removed by the least squares method. The remaining phase fluctuations allow consistent studying of their coordinated behavior and timing, using the Pearson correlation coefficient for dependence evaluation. This study includes program experiments to evaluate the calculation efficiency in the phase grouping task. The paper also overviews some single-threaded and multi-threaded computing models. It is shown that the phase grouping algorithm for meteorological data can be parallelized and that a multi-threaded implementation leads to a 25-30% increase in the performance.

Surface layer temperature inversion in the Bay of Bengal: Main characteristics and related mechanisms

AbstractSurface layer temperature inversion (SLTI), a warm layer sandwiched between surface and subsurface colder waters, has been reported to frequently occur in conjunction with barrier layers in the Bay of Bengal (BoB), with potentially commensurable impacts on climate and postmonsoon tropical cyclones. Lack of systematic measurements from the BoB in the past prevented a thorough investigation of the SLTI spatiotemporal variability, their formation mechanisms, and their contribution to the surface temperature variations. The present study benefits from the recent Research Moored Array for African‐Asian‐Australian Monsoon Analysis and Prediction (RAMA) buoys located in BoB along 90°E at 4°N, 8°N, 12°N, and 15°N over the 2006–2014 period. Analysis of data from these RAMA buoys indicates that SLTI forms after the summer monsoon and becomes fully developed during winter (December–February). SLTI exhibits a strong geographical dependency, with more frequent (80% times during winter) and intense inversions (amplitude, ΔT ∼ 0.7°C) occurring only in the northern BoB compared to central and southern Bay. SLTI also exhibits large interannual and intraseasonal variations, with intraseasonal amplitude significantly larger (ΔT ∼ 0.44°C) than the interannual amplitude (∼0.26°C). Heat budget analysis of the mixed layer reveals that the net surface heat loss is the most dominant process controlling the formation and maintenance of SLTI. However, there are instances of episodic advection of cold, low‐saline waters over warm‐saline waters leading to the formation of SLTI as in 2012–2013. Vertical processes contribute significantly to the mixed layer heat budget during winter, by warming the surface layer through entrainment and vertical diffusion.

Patterning and pattern selection in a surface layer: Feedback between point defects population and surface layer temperature variations

Abstract We study dynamics of pattern formation in a prototype system of nonequilibrium point defects in thin foils under sustained nonequilibrium conditions. A reaction–diffusion model describing spatio-temporal behaviour of both vacancy population and local temperature of a surface layer is used. It is shown that pattern selection processes caused by coupling between defect population and local temperature of a surface are realized. Associated oscillatory dynamics of main statistical moments of both vacancy concentration field and surface layer temperature is analysed in detail. It is found that during the system evolution spatial distribution of local temperature variations of the surface layer relates to vacancy population distribution. It is shown that the mean size of vacancy clusters (from 30 nm up to 300 nm) evolves in oscillatory manner due to pattern selection processes. Morphology of defect complexes can be controlled by defects generation rate.

Impact of Contactless Apoptosis-Inducing RF on Temperature of Human Skin Surface and Subcutaneous Layer as well as Porcine Histology: A Pilot Study

Radiofrequency (RF) technology has been developed as a noninvasive method to reduce subcutaneous abdominal fat. The aim of this study was to measure the changes of human skin surface temperature and human subcutaneous fat layer temperature, as well as to evaluate the histologic change in porcine adipocytes during and after treatment with contactless apoptosis-inducing RF device.

From skin to bulk: An adjustment technique for assimilation of satellite-derived temperature observations in numerical models of small inland water bodies

Data Assimilation (DA) has been proposed for multiple water resources studies that require rapid employment of incoming observations to update and improve accuracy of operational prediction models. The usefulness of DA approaches in assimilating water temperature observations from different types of monitoring technologies (e.g., remote sensing and in-situ sensors) into numerical models of in-land water bodies (e.g., lakes and reservoirs) has, however, received limited attention. In contrast to in-situ temperature sensors, remote sensing technologies (e.g., satellites) provide the benefit of collecting measurements with better X-Y spatial coverage. However, assimilating water temperature measurements from satellites can introduce biases in the updated numerical model of water bodies because the physical region represented by these measurements do not directly correspond with the numerical model's representation of the water column. This study proposes a novel approach to address this representation challenge by coupling a skin temperature adjustment technique based on available air and in-situ water temperature observations, with an ensemble Kalman filter based data assimilation technique. Additionally, the proposed approach used in this study for four-dimensional analysis of a reservoir provides reasonably accurate surface layer and water column temperature forecasts, in spite of the use of a fairly small ensemble. Application of the methodology on a test site - Eagle Creek Reservoir - in Central Indiana demonstrated that assimilation of remotely sensed skin temperature data using the proposed approach improved the overall root mean square difference between modeled surface layer temperatures and the adjusted remotely sensed skin temperature observations from 5.6°C to 0.51°C (i.e., 91% improvement). In addition, the overall error in the water column temperature predictions when compared with in-situ observations also decreased from 1.95°C (before assimilation) to 1.42°C (after assimilation), thereby, giving a 27% improvement in errors. In contrast, doing data assimilation without the proposed temperature adjustment would have increased this error to 1.98°C (i.e., 1.5% deterioration).

Surface combustion on a ceramics-coated foamed-metal matrix

The results of a comparative study of the characteristics of surface combustion in the infrared mode on a flat and volumetric foamed-metal matrix with a ceramic (alumina) coating are reported. The coating of thickness ~200 μm was applied by using the detonation method. It was shown that the covering of the matrix with a material having a lower emissivity and thermal diffusivity causes the flame front to immerse into the matrix and increases the surface layer temperature. For combustion on a flat matrix at a firing rate of ~75 W/cm2, the concentrations of nitrogen oxides and carbon monoxide were up to two times lower. For combustion in a volumetric matrix at a firing rate of ~30 W/cm2, the reduction in the concentration of nitrogen oxides was two to three times lower.

Численно-аналитический метод расчета температурного поля полуограниченного тела с использованием показательных функций

Background: The temperature of solid bodies participating in heat exchange with a gas or a liquid environment at Fourier's numbers below 0,05 changes only in the surface layer. The thickness of this layer changes in time, therefore, calculation of temperature fields of these bodies is rather difficult. It is quite urgent to solve the problem of calculating temperature fields of semi-limited bodies for modeling the initial stage of intensive heating (cooling) of the equipment and protections of heat power installations. Earlier, analytical or numerical methods were applied to calculation of temperature fields with a mobile border of thermal aggitation. The former ones had insufficient accuracy in solving real nonlinear problems of heat conductivity, and the latter − were extremely labor-consuming. In recent years many research teams have been developing more effective numerical and analytical methods. Materials and Methods: In order to solve the differential equation of heat conduction with boundary conditions of the IIId kind, we used the numerical method of finite differences and numerical-analytical method. Results: We have developed formulas for calculation of the parameters of the exponential function describing the distribution of the surface layer temperatures. By the initial and end conditions of heat exchange, we analytically determined the functions of estimated time end. The calculation of the temperature field dynamics was reduced to the numerical solution of the differential equation that simplifies the calculation procedure. We also improved the technique of conjugate heat exchange calculation within the estimated period of time at high temperature growth rates of the  «Вестник ИГЭУ» Вып. 2 2016 г.  ФГБОУВО «Ивановский государственный энергетический университет имени В.И. Ленина» 2 surface under heating. Calculations were made to assess the calculation method efficiency. The comparatively simple numerical-analytical method of temperature fields of semi-limited bodies was specified. Conclusions: The study of this method has shown that the addition of a mathematical description of additional conditions improves the accuracy of calculation of temperatures and their gradients.

Mapping urban heat islands of arctic cities using combined data on field measurements and satellite images based on the example of the city of Apatity (Murmansk Oblast)

This article presents the results of a study of the urban heat island (UHI) in the city of Apatity during winter that were obtained according to the data of field meteorological measurements and satellite images. Calculations of the surface layer temperature have been made based on the surface temperature data obtained from satellite images. The experimental data on air temperature were obtained as a result of expeditionary meteorological observations, and the experimental data on surface temperature were obtained based on the data of the space hyperspectral Moderate-Resolution Imaging Spectroradiometer (MODIS) system, channels 31 and 32 (10.78–11.28 and 11.77–12.27 micrometers, respectively). As a result of the analysis of temperature fields, an intensive heat island (up to 3.2°C) has been identified that was estimated based on the underlying surface temperature, and its mean intensity over the observation period significantly exceeds the representative data for European cities in winter. It has also been established that the air temperature calculated according to the MODIS data is systematically higher under winter conditions than the air temperature from direct measurement data.

Modeling and Experimental Investigations of the Surface Layer Temperature of Titanium Alloys during AEDG Processing

Observing the latest manufacturing processes, the following tendencies can be noted: the gain of the energetic efficiency and shortening of the processing time with parallel preservation of the dimensions tolerance, shape tolerance and outer layer quality of the processed workpiece. Also the possibilities of gaining efficiency by rising criteria for process parameters are limited. It is mainly observed in the processing of hard machinable materials like titanium alloys or sintered carbides. Problems related to poor machinability were revealed during the final manufacturing processes using abrasive grinding [1,2]. In this work the results which have been presented are related to the influence by selected electrical parameters of the Abrasive Electrodischarge Grinding (AEDG) on the surface layer temperature of machined samples, in comparison to conventional grinding. Also the change in temperature during the AEDG has been depicted. The basis of this work is similar to the investigations of the deep grinding of surfaces of the titanium alloy Ti6Al4V using CBN and a diamond grinding wheel. For the comparative evaluation of the conventional grinding and AEDG, measurements of the specific grinding energy, energy of the spark discharge and internal stresses in the surface layer have been used.

Estructura de la población del cangrejo rojo de manglar, Goniopsis cruentata (Decapoda: Grapsidae) bajo diferentes impactos de pesca: Implicaciones para la gestión de los recursos.

<p>The red mangrove crab, <em>Goniopsis cruentata,</em> influences the recruitment and composition of plant species in the mangrove ecosystem and it is an important fishery resource. Nevertheless, no current management and conservation plans are available for this species for the Brazilian coast. This investigation evaluated the population structure and reproductive biology in populations of <em>G. cruentata</em> under contrasting fishery pressures. The sampling program was carried out in two mangroves, Vaza-Barris and Sergipe River, from January through December 2011. Crabs from both mangroves were randomly collected by a professional fisherman during daytime low tide periods, using a fishing rod baited with pieces of a locally abundant gastropod, <em>Pugilina morio</em>, during 20min/area (catch per unit effort). Monthly measurements of air, sediment surface layer and water temperatures were obtained with a digital thermometer and salinity with an optical refractometer. Both crab populations were compared concerning their abundance, body size, sex ratio, size at onset of sexual maturity and fecundity (FI). Abiotic factors (air, water and mud temperature; and salinity) showed no significant differences between sampling localities. A total of 4 370 crabs were sampled, 2 829 from the Sergipe River and 1 541 from the Vaza-Barris River. The abundance and body size of crabs were compared between mangroves, and statistically significant differences were found. The sex ratio for both populations differed from the expected 1:1 ratio, and a significant deviation in favor of juvenile males was obtained, while adults showed a bias toward females. The estimated size at onset of sexual maturity for both sexes was similar in both populations. However, the populations differed significantly in the number and volume of eggs: a higher FI was obtained in females from the Sergipe River, while a higher egg volume was observed in females from the Vaza-Barris River mangrove. These results indicated a tendency to decrease the body size, the abundance of crabs and the reproductive potential of the species, with higher fishing intensities, reinforcing the need to develop a management plan as well as to establish conservation units for <em>G. cruentata</em> in the Northeastern Brazilian coast. Habitat loss in conjunction with long-term overfishing can have irreversible consequences, which can impact not only the populations of commercially exploited crabs, but the dynamics of virtually the entire mangrove ecosystem.</p>

The Urban Heat Island of Dublin City During the Summer Months Urban Heat Island of Dublin City

The summer temperature regime of Dublin city shows a marked diurnal variation due to numerous interlinked causes. At night, urban heat island intensities of up to 8°C can be anticipated in calm, clear conditions. With less than 4 okta cloud, and windspeeds below 5m/s. cold islands develop in the city's parks. Katabatic cold flows and large scale inversions develop when regional windspeeds are less than 3m/s. During the day, although the urban heat island phenomenon is generally absent, temperature contrasts of over 6°C can be expected for topographical reasons. Even with limited sunshine, sea-breezes will develop and affect coastal regions, and areas directly in the lee of hills will commonly experience compressional warming. Heating in sheltered valleys or in the city centre will cause high adiabatic lapse rates to develop. Due to the combination of coastal configuration, topography, and building density, the surface layer temperature profile of Dublin city can be said to be complex, unique, multifaceted. but eminently predictable.

Mean diel variability of surface energy fluxes over Manso Reservoir

Mean diel cycle of latent (E), sensible (H), net longwave (Lwnet), net shortwave (Sw), and net surface heat flux balance (S) were estimated from hourly meteorological and subsurface water temperature time series acquired for ~1 month during mid-austral autumn by a buoy system in a large tropical reservoir in Brazil. E and H were in phase and had their maximum (E = 163 Wm−2; H = 39 Wm−2) at early morning and minimum (E = 112 Wm−2; H = 6 Wm−2) midafter-noon, resulting in Bowen ratios of 0.24 and 0.06, respectively. Heat loss by evaporation therefore dominates over sensible heat used to warm surface atmosphere. Atmospheric instability was present almost all the time, increasing latent and sensible heat flux exchange coefficients by ~50% over their neutral values (from 1.4 × 10−3 to 2.2 × 10−3). Mean Lwnet varied from 76 at late afternoon to 89 Wm−2 at early morning, indicating its importance in the overall surface heat flux balance. All 3 fluxes (E, H, and Lwnet) were positive (reservoir losing energy) throughout the day. The integrated daily average net energy budget S (net short wave radiation minus E + H + Lwnet) was ~ −60 Wm−2; nighttime energy loss exceeded daytime gain, with consequent cooling of the reservoir. A mean temperature drop of about −0.1 °C d−1 was obtained by fitting a linear trend line to observed daily mean surface temperatures. In a qualitative way, diel time variations of surface water temperature were consistent to the time variability of S, indicating the dominant role of the surface heat budget in modulating surface layer temperatures of the reservoir.

Oxidation effect on steel corrosion and thermal loads during corium melt in-vessel retention

During a severe accident with core meltdown, the in-vessel molten core retention is challenged by the vessel steel ablation due to thermal and physicochemical interaction of melt with steel. In accidents with oxidizing atmosphere above the melt surface, a low melting point UO2+x–ZrO2–FeOy corium pool can form. In this case ablation of the RPV steel interacting with the molten corium is a corrosion process.Experiments carried out within the International Scientific and Technology Center's (ISTC) METCOR Project have shown that the corrosion rate can vary and depends on both surface temperature of the RPV steel and oxygen potential of the melt. If the oxygen potential is low, the corrosion rate is controlled by the solid phase diffusion of Fe ions in the corrosion layer. At high oxygen potential and steel surface layer temperature of 1050°C and higher, the corrosion rate intensifies because of corrosion layer liquefaction and liquid phase diffusion of Fe ions.The paper analyzes conditions under which corrosion intensification occurs and can impact on in-vessel melt retention (IVR).