scholarly journals Seasonal Variation and Characterization of the Micrometeorology in Linpan Settlements in the Chengdu Plain, China: Microclimatic Effects of Linpan Size and Tree Distribution

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hua Zong ◽  
De-hua Pu ◽  
Mei-lin Liu
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Air Temperature ◽  
Radiation Flux ◽  
Negative Relationship ◽  
Distribution Patterns ◽  
Tree Distribution ◽  
Chengdu Plain ◽  
Solar Radiation Flux

Linpan settlements (abbreviated as Linpan) are the most important traditional type of rural settlement in the Chengdu Plain, and they are an important part of the agroforestry ecological system in southwest China. In this study, we measured the micrometeorological parameters (air temperature, solar radiation, relative humidity, and wind speed) in 12 Linpans for two years to determine the seasonal micrometeorology variations; then, we explored the impacts of Linpan size and tree distribution on the Linpan micrometeorology. The results show that the Linpans undergo seasonal cooling (from 0.6 to 1.3°C), humidification (from 0.9% to 4.1%), reduction in solar radiation flux (from 92.1 to 496.0 W/m2), and changes in wind speed (by 0.4 to 0.5 m/s) compared to the surrounding environment. Both solar radiation flux and wind speed showed the following decreasing trend with respect to sampling positions in the Linpan: outside > edge > center. The Linpan size did not affect the solar radiation flux or wind speed over the four seasons. The main factor affecting solar radiation flux and wind speed was the horizontal tree distribution not the Linpan size. However, the Linpan size was significantly correlated with the air temperature in summer and winter. Large Linpans (>5 × 103 m2) showed better ability to control the temperature to within a comfortable range in extremely hot and cold seasons. The Linpan size also showed a negative relationship with the relative humidity, but only in winter. Among the tree distribution patterns, a scattered distribution was optimal to achieve a comfortable micrometeorology over the course of the year. In addition, we suggest some ways to adapt the Linpan micrometeorology, which could be used to protect traditional Linpans, as well as for ecological restoration.

scholarly journals Predicting the Cooling Potential of Different Shading Methods for Greenhouses in Arid Regions

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4716 ◽  
Author(s):  
Ahmed Abdel-Ghany ◽  
Ibrahim Al-Helal ◽  
Fahad Alkoaik ◽  
Abdullah Alsadon ◽  
Mohamed Shady ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Arid Regions ◽  
Radiation Flux ◽  
Cooling Effect ◽  
Plastic Film ◽  
Solar Radiation Flux ◽  
Slaked Lime ◽  
Radiation Transmission

Shading greenhouses in a hot and sunny climate is essential to reduce the inside greenhouse air temperature. However, the type and location of nets need to be addressed properly to determine the shading method that provides a better cooling effect on the greenhouse air. This study was conducted to evaluate the effects of five different shading methods on greenhouse microclimates, and to investigate the cooling potential of each method. Four greenhouse models covered with 200-µm thick plastic film were used for the study: one was kept as control (C), one was whitened with slaked lime (L), and two were shaded with white and black nets (50% shading factor) deployed simultaneously at two locations, in contact (WC, BC) and at 20-cm distance from the cladding film (WD, BD). The microclimatic parameters were measured inside and outside the greenhouse models, and the cooling potential (CP) was predicted for each shading method. The results showed that the black net at 20-cm distance (BD) is desirable as it provides high CP with a reasonable solar radiation transmission. The maximum CP was estimated as 8.5 °C, 8 °C, 6 °C, 3.2 °C, and 2.1 °C for L, BD, BC, WD, and WC, respectively. Shading with white nets is not recommended because their cooling potential is very low. Based on these results, we developed correlations for predicting the CP for each shading method as a function of the transmitted solar radiation flux (Si). These correlations depend on Si. Accordingly, they can be used for small greenhouses, whitewashed with a slaked lime of any concentration, or shaded with a black net having any shading factor.

scholarly journals Investigation on the Temperature Distribution of Asphalt Overlay on the Existing Cement Concrete Pavement in Hot-Humid Climate in Southern China

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zuzhong Li ◽  
Yayun Zhang ◽  
Chunguang Fa ◽  
Xiaoming Zou ◽  
Haiwei Xie ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Prediction Model ◽  
Air Temperature ◽  
Concrete Pavement ◽  
Humid Climate ◽  
Temperature Prediction ◽  
Asphalt Overlay ◽  
Hot Humid Climate

Temperature is known to be one of the most important factors affecting the design and performance of asphalt concrete pavement. The distresses of asphalt overlay are closely related to its temperature, particularly in Guangxi, a hot-humid-climate region in China. This research is to analyze the impact of meteorological factors on temperature at 2 cm depth in asphalt overlay by ReliefF algorithm and also obtain the temperature prediction model using MATLAB. Two test sites were installed to monitor the temperatures at different pavement depths from 2014 to 2016; meanwhile, the meteorological data (including air temperature, solar radiation, wind speed, and relative humidity) were collected from the two meteorological stations. It has been found that the temperature at 2 cm depth experiences greater temperature variation, and the maximum and minimum temperatures of asphalt overlay, respectively, occur at 2 cm depth and on the surface. Besides, the results of ReliefF algorithm have also shown that the temperature at 2 cm depth is affected significantly by solar radiation, air temperature, wind speed, and the relative humidity. Based on these analyses, the prediction model of maximum temperature at 2 cm depth is developed using statistical regression. Moreover, the data collected in 2017 are used to validate the accuracy of the model. Compared with the existing models, the developed model was confirmed to be more effective for temperature prediction in hot-humid region. In addition, the analysis of rutting depth and overlay deformation for the two test sections with different materials is done, and the results have shown that reasonable structure and materials of asphalt overlay are vital to promote the high-temperature antideforming capability of pavement.

scholarly journals Efectos de las condiciones ambientales sobre el comportamiento ingestivo en bovinos de carne en un sistema intensivo en el Valle del Sinú

2013 ◽  
Vol 13 (2) ◽  
pp. 207 ◽  
Author(s):  
Emiro Suárez P. ◽  
Sony Reza G. ◽  
Eliecer Díaz A. ◽  
Fredy García C. ◽  
Iván Pastrana V. ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Beef Cattle ◽  
Air Temperature ◽  
Ingestive Behavior ◽  
Average Weight ◽  
Zebu Cattle ◽  
Panicum Maximum ◽  
Atmospheric Variables

<p>Incrementos en la temperatura ambiental y la humedad relativa, unidas al efecto de la radiación solar, ocasionan pérdidas en el bienestar animal, afectando la conducta ingestiva y la productividad animal. Por ello el objetivo de este estudio fue analizar las relaciones entre las variables atmosféricas, como temperatura del aire, humedad relativa, velocidad del viento y radiación solar, con los tiempos de pastoreo y de rumia de bovinos cebú comercial. La investigación se llevó a cabo durante 96 días, entre julio-octubre de 2010, en el C.I. Turipaná de Corpoica (Cereté, Colombia). Bovinos machos enteros (27), con peso promedio 314 ± 29 kg, pastorearon en un área de 18 hectáreas, establecidas en <em>Panicum maximum </em>cv. Mombasa, <em>Cynodonnlem fluensis </em>y <em>Brachiaria </em>híbrido cv. Mulato II, sin disponibilidad de sombra. Se realizaron ocho evaluaciones durante 8 días dentro del periodo experimental de las variables atmosféricas e ingestivas y las anotaciones se hicieron en un lapso de 12 horas continuas (6:00 AM a 6:00 PM). Los resultados resaltan que al aumentar la temperatura del aire, humedad relativa y la radiación solar, disminuyó el tiempo de pastoreo y aumentó el tiempo de rumia, mientras que al aumentar la velocidad del viento se incrementó el tiempo de pastoreo y disminuyó el tiempo de rumia. Los resultados obtenidos indicaron que la temperatura del aire, humedad relativa, radiación solar y velocidad del viento, presentaron una influencia directa sobre el comportamiento ingestivo de los bovinos de carne manejados en sistemas intensivos (sin sombra) en el Valle del Sinú. </p><p> </p><p><strong>Effects of environmental conditions on feeding behavior in beef cattle in an intensive system in the Sinú Valley </strong></p><p>Increases in temperature and relative humidity together with the solar radiation effect are detrimental to animal welfare, affecting their behavior when it comes to feeding and digestive behavior, which affects their productivity. Therefore, the goal of this research was to analyze the link between atmospheric variables, air temperature, relative humidity, wind speed and solar radiation to the time of grazing and rumination of commercial Zebu cattle. The research took place from July to October 2010, at the Turipaná Center, Corpoica (Cereté, Colombia). Male intact bovines (27), with an average weight of 314 ± 29 kg, grazed in an area of 18 hectares, established with <em>Panicum maximum </em>cv. Mombasa, <em>Cynodonnlem fluensis </em>and <em>Brachiaria </em>hybrid cv. Mulato II, without shade availability. Eight evaluations were conducted for 8 days in the experimental period for atmospheric variables and ingestion. Notes were taken in 12 hour time frames (6:00 AM a 6:00 PM). The outcome showed that as the air temperature, relative humidity and solar radiation increased, the grazing time decreased and rumination time lasted longer. However, when wind speed increased, grazing time increased as well and rumination took less time. The results showed that the air temperature, relative humidity, solar radiation and wind speed had a direct influence on the ingestive behavior of beef cattle managed in intensive systems (shadeless) in Valle del Sinú. </p>

scholarly journals Seasonal variation of some atmospheric parameters in fresh water swamp and Sudan Savanna areas of Nigeria

2021 ◽  
Vol 40 (4) ◽  
pp. 740-750
Author(s):  
F.O. Aweda ◽  
J.O. Agbolade ◽  
J.A. Oyewole ◽  
M. Sanni
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Minimum Temperature ◽  
Negative Relationship ◽  
Maximum Temperature ◽  
Atmospheric Parameters ◽  
Freshwater Swamp ◽  
Significant Negative Relationship ◽  
Sudan Savanna

The year in year out variation in atmospheric parameters, solar radiation, and meteorological variables such as ambient temperature, relative humidity RH, wind speed etc, are posies that can be and are used to describe the atmospheric conditions. Ten years of data obtained from the Nigerian Meteorological Agency (NiMet) was analysed. Results showed that solar radiation rises from January to get to its peak in April which is maintained till August before it begins to fall again with the Sudan savanna area (Maiduguri) having a value of (15.70 MJm-2month-1) and freshwater swamp area (Ikeja) having the value of (10.16 MJm-2month-1). The extraterrestrial radiations calculated for the two stations are 333.53 (MJm-2month-1) and 195.53 (MJm-2month-1) respectively. However, the relative humidity of Ikeja (84.54%) is higher as compared to that of Maiduguri (42.23%). The minimum temperature ranges observed for the two stations varies from (22 - 24)0C and (12 - 26)°C, while the maximum temperature was as high as 33°C and 40°C obtained in April for Ikeja and Maiduguri, respectively. Similarly, the average wind speed is higher for Ikeja (4.97m/s) than for Maiduguri (4.62m/s). The result of the statistical correlation reveals that, in Maiduguri, solar radiation was found to have a significant negative relationship with relative humidity (r = -.256, p<0.01) and a significant positive relationship with minimum and maximum temperature (p<0.05). This means that minimum and maximum temperatures increase as solar radiation increases (p<0.05). Relative humidity decreases as solar radiation increases. In Ikeja, solar radiation was found to have a significant negative relationship with relative humidity (r =-.350, p<0.01) and wind speed (r = -146, p<0.05) and significant positive relationship with minimum temperature (r =.410, p<0.05) and maximum temperature (r =.575, p<0.01). In conclusion, the variables like relative humidity, minimum temperature and wind speed are higher in the freshwater swamp area of Nigeria as compared to the Sudan savanna area, while the solar radiation, extraterrestrial radiation and maximum temperature are generally higher in the Sudan savanna area of Nigeria.

scholarly journals Estimation of the Influence of Meteorological Factors on the Potential Evapotranspiration of Yanhe River Basin

2021 ◽  
Author(s):  
yu luo ◽  
Peng Gao ◽  
Xingmin Mu ◽  
dexun Qiu
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
River Basin ◽  
Air Temperature ◽  
Meteorological Factors ◽  
Sensitivity Coefficient ◽  
Downward Trend ◽  
Upward Trend ◽  
Temporal And Spatial

Potential evapotranspiration (ET) is an important expenditure item in the hydrological cycle. Quantitative estimation of the influence of meteorological factors on ET can provide a scientific basis for the study of the impact mechanism of climate change on the hydrological cycle. In this paper, the Penman-Monteith method was used to calculate ET. The Mann-Kendall statistical test and the Inverse Distance Weighting method were used to analyze the temporal and spatial characteristics of the sensitivity coefficient of ET to meteorological factors and contribution rate of meteorological factors to ET. And the reasons for the change of ET were quantitatively explored in combination with the change trend of meteorological factors. The results showed that the average ET in the Yanhe River Basin from 1978 to 2017 was 935.92mm. Except for Ganquan Station, ET showed an upward trend. Generally, the sensitivity coefficient of air temperature (0.08), wind speed (0.19) and solar radiation (0.42) was positive and the sensitivity coefficient of relative humidity (-0.41) was negative. But there were significant temporal and spatial differences. The upward trend of air temperature and solar radiation contributed 1.09% and 0.55% to ET. Respectively, the downward trend of wind speed contributed -0.63% And the downward trend of relative humidity contributed to -0.85% of ET. Therefore, the decrease of relative humidity did not cause the increase of ET in Yanhe River basin. The dominant factor of the upward trend of ET was air temperature. But the dominant factors of ET had significant temporal and spatial differences. The downward trend of wind speed at Ganquan Station contributed -9.16% to ET, which indicated the dominant factor of “evaporation paradox” in Ganquan area was wind speed. Generally, the increase of ET was related to air temperature, wind speed and solar radiation. And the decrease of ET was related to relative humidity.

scholarly journals Influence of Meteorological Factors on the Potential Evapotranspiration in Yanhe River Basin, China

2021 ◽  
Author(s):  
yu luo ◽  
Peng Gao ◽  
Xingmin Mu
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
River Basin ◽  
Air Temperature ◽  
Hydrological Cycle ◽  
Meteorological Factors ◽  
Potential Evapotranspiration ◽  
Sensitivity Coefficients ◽  
The Impact

Potential evapotranspiration (ET) is an essential component of the hydrological cycle, and quantitative estimation of the influence of meteorological factors on ET can provide a scientific basis for studying the impact mechanisms of climate change. In the present research, the Penman-Monteith method was used to calculate ET. The Mann-Kendall statistical test with the inverse distance weighting were used to analyze the spatiotemporal characteristics of the sensitivity coefficients and contribution rates of meteorological factors to ET to identify the mechanisms underlying changing ET rates. The results showed that the average ET for the Yanhe River Basin, China from 1978–2017 was 935.92 mm. Save for a single location (Ganquan), ET increased over the study period. Generally, the sensitivity coefficients of air temperature (0.08), wind speed at 2 m (0.19), and solar radiation (0.42) were positive, while that of relative humidity was negative (-0.41), although significant spatiotemporal differences were observed. Increasing air temperature and solar radiation contributed 1.09% and 0.55% of the observed rising ET rates, respectively; whereas decreasing wind speed contributed -0.63%, and relative humidity accounted for -0.85%. Therefore, it was concluded that the decrease of relative humidity did not cause the observed ET increase in the basin. The predominant factor driving increasing ET was rising air temperatures, but this too varied significantly by location and time (intra- and interannually). Decreasing wind speed at Ganquan Station decreased ET by -9.16%, and was the primary factor underlying the observed, local “evaporation paradox.” Generally, increases in ET were driven by air temperature, wind speed and solar radiation, whereas decreases were derived from relative humidity.

scholarly journals Influence of Meteorological Factors on the Potential Evapotranspiration in Yanhe River Basin, China

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1222
Author(s):  
Yu Luo ◽  
Peng Gao ◽  
Xingmin Mu
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
River Basin ◽  
Air Temperature ◽  
Hydrological Cycle ◽  
Meteorological Factors ◽  
Potential Evapotranspiration ◽  
Sensitivity Coefficients ◽  
The Impact

Potential evapotranspiration (ET0) is an essential component of the hydrological cycle, and quantitative estimation of the influence of meteorological factors on ET0 can provide a scientific basis for studying the impact mechanisms of climate change. In the present research, the Penman–Monteith method was used to calculate ET0. The Mann–Kendall statistical test with the inverse distance weighting were used to analyze the spatiotemporal characteristics of the sensitivity coefficients and contribution rates of meteorological factors to ET0 to identify the mechanisms underlying changing ET0 rates. The results showed that the average ET0 for the Yanhe River Basin, China from 1978–2017 was 935.92 mm. Save for a single location (Ganquan), ET0 increased over the study period. Generally, the sensitivity coefficients of air temperature (0.08), wind speed at 2 m (0.19), and solar radiation (0.42) were positive, while that of relative humidity was negative (−0.41), although significant spatiotemporal differences were observed. Increasing air temperature and solar radiation contributed 1.09% and 0.55% of the observed rising ET0 rates, respectively; whereas decreasing wind speed contributed −0.63%, and relative humidity accounted for −0.85%. Therefore, it was concluded that the decrease of relative humidity did not cause the observed ET0 increase in the basin. The predominant factor driving increasing ET0 was rising air temperatures, but this too varied significantly by location and time (intra- and interannually). Decreasing wind speed at Ganquan Station decreased ET0 by −9.16%, and was the primary factor underlying the observed, local “evaporation paradox”. Generally, increase in ET0 was driven by air temperature, wind speed and solar radiation, whereas decrease was derived from relative humidity.

scholarly journals Impact of Micro-climatic variations on Forest Ecosystem in Mid Hills of Himachal Pradesh

2017 ◽  
Vol 12 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Purnima Mehta ◽  
P. K Baweja ◽  
R. K. Aggarwal
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Soil Temperature ◽  
Air Temperature ◽  
Forest Ecosystem ◽  
Forest Canopy ◽  
Oak Forest ◽  
Bare Area ◽  
Climatic Variations

A study was carried out on “Impact of micro-climatic variations on forest ecosystem in mid hills of Himachal Pradesh” during winter and summer seasons of 2015-16. Comparisons of below forest canopy and open sites were carried out for abiotic and biotic factors under five forest ecosystems (chir pine forest, mixed forest, ban oak forest, agriculture field and bare area) and analysed the forest influence on local winter and summer climate according to forest type, soil type, slope orientation, tree height and diameter at breast height by using RBD design. Seasonal and diurnal variations in microclimatic variables viz., air temperature, soil temperature, relative humidity, wind speed and wind direction were measured with Portable weather station (Delta T) at afternoon 2:00-4:00 PM fortnightly in each forest ecosystem and bare area during winter and summer season. Solar radiation and albedo were measured with Pyranometer (Kipp and Zonen) at 1.35 m height. A significant decrease was attained in below forest canopy and bare area data for ambient temperature (2.5-5.0 oC), soil temperature (1.5-3.6 oC) solar radiation (13.2-47.4 Wm-2), albedo (0.15-0.21) and increased relative humidity (7-18%), soil moisture (8.0-15.2%). Among different forest ecosystem, the diurnal trends in microclimatic parameters showed large variations. The ambient air temperature ranged from 02.2-16.3 oC and 14.2- 30.7 oC where as soil temperature ranged from 07.4- 16.5 oC and 15.4-32.7 oC, however relative humidity ranged from 37- 88 per cent and 14-60 per cent among different forest ecosystem during winter and summer seasons, respectively. Mico-climatic variables under Ban-Oak forest revealed significant lowest air temperature, highest relative humidity and less wind speed.

scholarly journals Detrended Multiple Cross-Correlation Coefficient applied to solar radiation, air temperature and relative humidity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea de Almeida Brito ◽  
Heráclio Alves de Araújo ◽  
Gilney Figueira Zebende
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Solar Energy ◽  
Correlation Coefficient ◽  
Air Temperature ◽  
Cross Correlation ◽  
Global Solar Radiation ◽  
Meteorological Variables ◽  
Hourly Data ◽  
Cross Correlations

AbstractDue to the importance of generating energy sustainably, with the Sun being a large solar power plant for the Earth, we study the cross-correlations between the main meteorological variables (global solar radiation, air temperature, and relative air humidity) from a global cross-correlation perspective to efficiently capture solar energy. This is done initially between pairs of these variables, with the Detrended Cross-Correlation Coefficient, ρDCCA, and subsequently with the recently developed Multiple Detrended Cross-Correlation Coefficient, $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2. We use the hourly data from three meteorological stations of the Brazilian Institute of Meteorology located in the state of Bahia (Brazil). Initially, with the original data, we set up a color map for each variable to show the time dynamics. After, ρDCCA was calculated, thus obtaining a positive value between the global solar radiation and air temperature, and a negative value between the global solar radiation and air relative humidity, for all time scales. Finally, for the first time, was applied $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2 to analyze cross-correlations between three meteorological variables at the same time. On taking the global radiation as the dependent variable, and assuming that $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}={\bf{1}}$$DMCx2=1 (which varies from 0 to 1) is the ideal value for the capture of solar energy, our analysis finds some patterns (differences) involving these meteorological stations with a high intensity of annual solar radiation.

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