scholarly journals Mobile Observation of Air Temperature and Humidity Distributions under Summer Sea Breezes in the Central Area of Osaka City

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1234
Author(s):  
Atsumasa Yoshida ◽  
Ryusuke Yasuda ◽  
Shinichi Kinoshita
Keyword(s):  
Air Temperature ◽  
Urban Areas ◽  
Thermal Environment ◽  
Central Area ◽  
Ground Surface ◽  
Sea Breeze ◽  
Observation Point ◽  
Sea Breezes ◽  
Temperature And Humidity ◽  
The Mean

Thermal environment of urban areas in the summertime has become harmful to human health due to global warming and the urban heat island (UHI) effect. Mobile observations enable us to obtain the distribution of air temperature at microscale, such as urban blocks, which cannot be captured by the coarse network of meteorological sites. A series of mobile measurements was executed in the central area of Osaka City in Japan, around the Nakanoshima district which lies between two rivers, to investigate the air temperature and humidity distributions in a built-up area under sea breeze conditions. Upper wind and surface temperature of the rivers were also observed using pilot balloons and infrared thermography camera, respectively. The mean air temperature in Nakanoshima was generally lower than that of the surrounding area. Urban geometries such as building density and building height seem to affect the mean air temperature by changing the ventilation efficiency. Humidity was inversely correlated with air temperature distribution but was higher at the confluence of rivers and green parks. The depth of the sea breeze layer was found to be about 1 km. Sea breezes close to the ground surface penetrated the city along the rivers, sandwiching the Nakanoshima district. During the daytime, the surface temperatures of the rivers were lower than the air temperature observed at the nearest stationary observation point, and the difference reached approximately 2 °C.

scholarly journals Heat and dry islands observed over Jakarta, Indonesia, in 2012

2014 ◽  
Vol 364 ◽  
pp. 140-144
Author(s):  
H. Widyasamratri ◽  
K. Souma ◽  
T. Suetsugi ◽  
H. Ishidaira ◽  
Y. Ichikawa ◽  
...  
Keyword(s):  
Urban Areas ◽  
Thermal Environment ◽  
Monsoon Season ◽  
Sea Breeze ◽  
Early Morning ◽  
Specific Humidity ◽  
Air Temperatures ◽  
Temperature And Humidity ◽  
Urbanized Areas ◽  
The Difference

Abstract. Recent population increases in urban areas of Asian countries have extended artificial land cover, increased energy consumption, and caused various problems. Higher air temperatures over urban areas (heat islands) degrade residential environments and affect human health. In Jakarta, the largest city in Indonesia and the second largest city in Asia, previous studies have relied on only a few observation points and physically-based models. To study the thermal environment in Jakarta in more detail, we performed seven fixed-point temperature and humidity observations from the dry to the pre-monsoon season (from 16 September to 18 October) in 2012. Over densely urbanized areas, higher temperatures and lower humidity were observed around noon compared with the sparsely urbanized areas. The maximum differences in temperature and specific humidity were found to be around 3 °C and 0.005 kg/kg, respectively. The differences in temperature and humidity became smaller in the afternoon because of the penetration of sea breezes. At night, the differences became larger again because the sea breeze weakened. Then, a difference of around 3°C was observed, except in the early morning. Although the difference in daytime temperature was smaller between densely urbanized areas and suburban areas, similar tendency was also confirmed in the daily time series averaged for sunny days in dry season.

Strretlight pole metal as the medium of Tetragonula sp nest in Indralaya, South Sumatra

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Hanifa Marisa
Keyword(s):  
Zea Mays ◽  
Air Temperature ◽  
Hevea Brasiliensis ◽  
Citrullus Lanatus ◽  
Ground Surface ◽  
Temperature And Humidity ◽  
Surface Diameter ◽  
Very High

An investigation had been done to Tetragonula (Tetragona) sp nest at Indralaya, South Sumatra to describe the Tetragonula sp nest that use streetlight pole as nest medium during April - May 2019. Purpossive sampling is used to select the target nest. Two streetlight pole found be used by Tetragonula sp as their home. The coordinate of location, heght from ground surface, diameter of streetlight pole, air temperature and humidity, and floral species around nest, were noted. Spot coordinate are S 30 14’ 19.2498’’ and E 1040 39’ 15,3288’’ ; 1,5 m above the ground surface, 12 cm diameter pole, highest air temperature was 35 o C at daylight (April and May 2019), 80 – 90 % humidity at April-May 2019; which Switenia macrophyla, Hevea brasiliensis, Zea mays, and Citrullus lanatus floral species are planted around. Air temperature in the pole is very high, around 40 0 C during daylight.

scholarly journals Urban Nocturnal Cooling Mediated by Bluespace

2021 ◽  
Author(s):  
Yuanfeng Cui ◽  
Leiqiu Hu ◽  
Zhihua Wang ◽  
Qi Li
Keyword(s):  
Air Temperature ◽  
Urban Areas ◽  
Rate Of Change ◽  
Analytical Models ◽  
Apparent Temperature ◽  
Urban Lakes ◽  
Temperature And Humidity ◽  
Alternative Means ◽  
Near Shore ◽  
Cooling Effects

Abstract The spatiotemporal characteristics of air temperature and humidity mediated by urban bluespace are investigated using a combination of dense network of climatological observations in a medium-sized US city, computational fluid dynamics and analytical modeling approaches. Both numerical simulation and observational results show that the rate of change of hourly averaged air temperature and humidity at 3.5 m over urban areas peaks two hours after sunset, while it decreases with time monotonically over greenspace, indicating different impacts due to presence of urban lakes. The apparent temperature decreases with distance to lakes in urban area due to higher near-shore humidity. This highlights that urban lakes located near city center can deteriorate the nighttime cooling effects due to elevated humidity. Finally, two analytical models are presented to explain the connection between the surface and air temperature as well as the spatial variation of air temperature and humidity adjacent to the urban lakes. These simplified models with parameters being inferred from the network of measurements have reasonably good performance compared to the observations. Compared to other sophisticated numerical simulations, these analytical models offer an alternative means that is easily accessible for evaluating the efficacy of bluespace on urban nocturnal cooling.

Performance Evaluation of a Smart Mobile Air Temperature and Humidity Sensor for Characterizing Intracity Thermal Environment

2020 ◽  
Vol 37 (10) ◽  
pp. 1891-1905
Author(s):  
Chang Cao ◽  
Yichen Yang ◽  
Yang Lu ◽  
Natalie Schultze ◽  
Pingyue Gu ◽  
...  
Keyword(s):  
Air Temperature ◽  
Humidity Sensor ◽  
Thermal Environment ◽  
Spatial Scales ◽  
Low Cost ◽  
Thermal Conditions ◽  
Absolute Humidity ◽  
Health Concern ◽  
Vegetation Fraction ◽  
Temperature And Humidity

AbstractHeat stress caused by high air temperature and high humidity is a serious health concern for urban residents. Mobile measurement of these two parameters can complement weather station observations because of its ability to capture data at fine spatial scales and in places where people live and work. In this paper, we describe a smart temperature and humidity sensor (Smart-T) for use on bicycles to characterize intracity variations in human thermal conditions. The sensor has several key characteristics of internet of things (IoT) technology, including lightweight, low cost, low power consumption, ability to communicate and geolocate the data (via the cyclist’s smartphone), and the potential to be deployed in large quantities. The sensor has a reproducibility of 0.03°–0.05°C for temperature and of 0.18%–0.33% for relative humidity (one standard deviation of variation among multiple units). The time constant with a complete radiation shelter and moving at a normal cycling speed is 9.7 and 18.5 s for temperature and humidity, respectively, corresponding to a spatial resolution of 40 and 70 m. Measurements were made with the sensor on street transects in Nanjing, China. Results show that increasing vegetation fraction causes reduction in both air temperature and absolute humidity and that increasing impervious surface fraction has the opposite effect.

scholarly journals Thermal and Geometric Controls on the Rate of Surface Air Temperature Changes in a Medium-Sized, Midlatitude City

2007 ◽  
Vol 46 (2) ◽  
pp. 241-247 ◽  
Author(s):  
Tomohiko Tomita ◽  
Hiroyuki Kusaka ◽  
Ryo Akiyoshi ◽  
Yoshiyuki Imasato
Keyword(s):  
Time Dependence ◽  
Air Temperature ◽  
Urban Areas ◽  
Mesoscale Model ◽  
Thermal Environment ◽  
Surface Air Temperature ◽  
Anthropogenic Heat ◽  
View Factor ◽  
Temperature Changes ◽  
The Impact

Abstract Gradual cooling in the evening forms a wintertime nocturnal urban heat island. This work, with a mesoscale model involving urban canopy physics, is an examination of how four thermal and geometric controls—anthropogenic heat QF, heat capacity C, thermal conductivity k, and sky-view factor ψs—modify the rate of surface air temperature changes ΔT/Δt. In particular, the time dependence is diagnosed through numerical experiments. The controls QF and k are major agents in the evening, when QF changes the evening ΔT/Δt linearly and k is logarithmic. The effects of C and ψs are large in the morning and in the afternoon with those of k. The impact of QF is, however, substantial only in the evening. Because the time dependence of C and k is different, the thermal inertia used as a parameter in the urban climate studies should be divided into two parameters: C and k. To improve the thermal environment in urban areas, the modification of QF and k could be effective.

scholarly journals Previsión del ambiente térmico para el ganado lechero mediante redes neuronales artificiales

2021 ◽  
Vol 1 (4) ◽  
pp. 104-119
Author(s):  
Pedro Hurtado de Mendoza Borges ◽  
Zaíra Morais dos Santos Hurtado De Mendoza ◽  
Pedro Hurtado de Mendoza Morais
Keyword(s):  
Neural Networks ◽  
Dairy Cattle ◽  
Thermal Environment ◽  
Absolute Error ◽  
Mato Grosso ◽  
Historical Series ◽  
Temperature And Humidity ◽  
Humidity Index ◽  
The Mean ◽  
Artificial Neural

El presente estudio tuvo como objetivo la previsión del ambiente térmico para el ganado lechero mediante redes neuronales artificiales, de acordó con la temperatura y humedad diaria. En la investigación se utilizaron los valores diarios de esas variables, disponibles en el Instituto Nacional de Meteorología de Brasil. Los datos correspondieron a las series históricas registradas en estaciones convencionales con tiempo de operación superior a 30 años hasta 2020. A continuación, se seleccionaron los municipios Canarana, Matupá, Nova Xavantina y Santo Antônio de Leverger, localizados en Mato Grosso, Brasil. Con base en los dados climatológicos, se estimó el Índice de Temperatura y Humedad diario en el calendario Juliano. Posteriormente, se probaron 35 arquitecturas de redes neuronales artificiales con tipología perceptrón de múltiples camadas, siendo la variable de entrada el día Juliano y la de salida el Índice de Temperatura y Humedad. La idoneidad de las redes fue verificada por el coeficiente de determinación, el error absoluto medio, el error cuadrático medio, el porciento medio del error absoluto y la normalidad de los residuos. No hubo diferencias entre los valores estimados por las redes y los obtenidos a partir de las series históricas. La rede de mejor desempeño y eficiencia para cada municipio, también fue comprobada por el análisis gráfico de los residuos. Se concluyó que las redes neuronales con tipología perceptron de dos camadas ocultas fueron apropiadas en el pronóstico del ambiente térmico natural para el ganado lechero.   The present study aimed to forecast the thermal environment for dairy cattle through artificial neural networks, according to the daily temperature and humidity. The research used the daily values of these variables, available in the National Institute of Meteorology of  Brazil. The data corresponded to the historical series registered in conventional stations with an operating time of more than 30 years until 2020. Next, the municipalities Canarana, Matupá, Nova Xavantina and Santo Antônio de Leverger, located in Mato Grosso, Brazil, were selected. Based on the climatological data, the Temperature and Humidity Index was determined for each day of the year in the Julian calendar. Subsequently, 35 artificial neural network architectures with multiple layer perceptron typology were tested, the input variable being the Julian day and the output variable being the Temperature and Humidity Index. The suitability of the networks was verified by the coefficient of determination, the mean absolute error, the mean square error, the mean percentage of the absolute error and the normality of the residuals. There were no differences between the values estimated by the networks and those obtained from the historical series. The network with the best performance and efficiency for each municipality was also verified by the graphic analysis of the residuals. It was concluded that the neural networks with perceptron typology of two hidden layers were appropriate in the forecast of the natural thermal environment for dairy cattle.

Opposite trends of sea-breeze speeds and gusts in Eastern Iberian Peninsula, 1961-2019

2021 ◽  
Author(s):  
Shalenys Bedoya-Valestt ◽  
Cesar Azorin-Molina ◽  
José A. Guijarro ◽  
Victor J. Sanchez-Morcillo
Keyword(s):  
Wind Speed ◽  
Iberian Peninsula ◽  
Atmospheric Circulation ◽  
Air Temperature ◽  
Large Scale ◽  
Sea Breeze ◽  
Sea Breezes ◽  
Long Term Trends ◽  
Large Scale Atmospheric Circulation

<p>Long-term trends of local winds such as sea breezes have been less addressed in climate research, despite their impacts on broad environmental and socioeconomic spheres, such as weather and climate, agriculture and hydrology, wind-power industry, air quality or even human health, among many others. In a warming climate, sea breezes could be affected by changes on air temperature, as these onshore winds are thermally-driven by gradients between the sea-land air, but also by ocean-atmosphere oscillations or changes in large-scale atmospheric circulation. In the last few decades, advances in wind trends studies evidenced a recovery in global wind stilling during the last 10 years, and differences in the sign-magnitude of wind speed trends were found at seasonal-scale, suggesting the hypothetic effect of the reinforcement of local wind circulations in the warm seasons.</p><p>In this study, we analyze for the first time the long-term trends, multidecadal variability and possible drivers of the sea-breeze speeds and gusts in Eastern Iberian Peninsula during the last 58 years (1961-2019), using homogenized wind speed and gusts data from 16 meteorological stations. To identify potential sea breeze episodes, we developed a robust automated method based on alternative criteria. Our results suggest a decoupling between the declining sea-breeze speeds and the strengthening of the maximum gusts for much of the 1961-2019 period at annual, seasonal and monthly scales, but differences based on locations were also found. Because sea breeze changes can be driven by multiple complex factors (i.e. land use changes, land-sea air temperature gradient, complex orography, etc.), the attribution of causes is challenging. To better understand the causes behind the opposite trends between sea-breeze speeds and gusts, we investigate the effect of e.g. the changes in large-scale atmospheric circulation or physical-local factors.</p>

scholarly journals Study on the Effect of Streets’ Space Forms on Campus Microclimate in the Severe Cold Region of China—Case Study of a University Campus in Daqing City

2020 ◽  
Vol 17 (22) ◽  
pp. 8389
Author(s):  
Hong Jin ◽  
Liang Qiao ◽  
Peng Cui
Keyword(s):  
Wind Speed ◽  
Air Temperature ◽  
Urban Areas ◽  
Thermal Environment ◽  
Heat Convection ◽  
Heat Radiation ◽  
View Factor ◽  
University Campus ◽  
Human Comfort ◽  
Open Type

In urban areas, local microclimate is influenced by architectural forms, which will in turn affect human comfort. Taking Daqing as an example, this article studies the microclimate of a university campus in the severe cold area in China. Based on the space features of the streets, we categorize the streets into three types: open type, semi-open type, and street-entry type. Through analysis, this article researches microclimates of the three kinds of streets, the influence of building heating on the surrounding thermal environment, the relationship between streets’ morphology features and microclimate and human comfort (physiological equivalent temperature, PET). By study and analysis, we have the following findings: for open-type streets, the average globe temperatures of streets with different orientations can reach 1.3 °C in winter because of the influence of sidewalk trees. For semi-open-type streets, streets temperature is under the influence of the locating directions of buildings. The maximum air temperature difference among streets with different building arrangements reaches 2.1 °C in winter. For street-entry-type streets, the height–width ratios and orientations of streets are related to the continuity degree of the street interfaces. The building interface acts as a heating element and affect the surrounding thermal environment by heat convection and heat radiation. Analysis demonstrates that heat convection has a more obvious effect on rising surrounding temperature than heat radiation. Buildings with higher heat radiation witness higher globe temperature. For street-entry-type streets and semi-open-type streets, the SVF (sky view factor) and L/C (plane opening rate) of streets are negatively correlated with temperature and PET, but positively correlated with wind speed. If the SVF increases 0.1, the air temperature will reduce 0.1 °C, the wind speed will increase 0.19 m/s, and the PET will reduce 0.7 °C.

Summer air temperature distribution and thermal environment in urban areas of Japan

2008 ◽  
Vol 9 (4) ◽  
pp. 209-213 ◽  
Author(s):  
Masahide Aikawa ◽  
Takatoshi Hiraki ◽  
Jiro Eiho
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Urban Areas ◽  
Thermal Environment
Sign in / Sign up

Export Citation Format

Share Document