COMPARISON ON COLORED COATING FOR ASPHALT AND CONCRETE PAVEMENT BASED ON THERMAL PERFORMANCE AND COOLING EFFECT

2016 ◽  
Vol 78 (5) ◽  
Author(s):  
Julia Md. Tukiran ◽  
Jamel Ariffin ◽  
Abdul Naser Abdul Ghani
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Thermal Performance ◽  
Ground Surface ◽  
Concrete Pavement ◽  
Concrete Sample ◽  
Pavement Surface ◽  
Solar Reflectance ◽  
Parking Lot ◽  
Colored Coating

In tropical climate, pavement surface temperature could reach up higher than the air temperature due to solar-energy absorption by pavement during the daytime. Colored ground surface such as in pedestrian walkway, parking lot, and bicycle track may be able to reduce the heat absorbed by the pavements. This paper reports the thermal performance of five different colors of coating applied at asphalt and concrete pavement surface. In order to investigate the thermal performance and solar reflectance of the colored coating pavement, infrared thermometer and solar power meter as well as thermal imager procedure were used. From the statistical analysis, it was found that all the colored coating on asphalt and concrete sample demonstrate lower surface temperature compared to conventional or uncoated asphalt and concrete. The highest surface temperature reduction and solar reflectance recorded was for the white coated asphalt sample was 17°C and 0.61, while for the white coated concrete sample was 10°C and 0.78. ENVI-met simulation is used for evaluating the thermal impact of applying the samples in site study. This study can assist in choosing more appropriate colored coatings for ground surface of the urban environment (pedestrian walkway, parking lot, plaza, etc.), and thus contribute to the reduction of the air temperature due to the heat-transfer phenomena as well as improve outdoor thermal comfort and cityscape appearance.

Modelling pavement temperature for winter maintenance operations

2004 ◽  
Vol 31 (2) ◽  
pp. 369-378 ◽  
Author(s):  
Aly Sherif ◽  
Yasser Hassan
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Negative Impact ◽  
Weather Conditions ◽  
Statistical Modelling ◽  
Dew Point ◽  
Road Maintenance ◽  
Winter Maintenance ◽  
Pavement Surface ◽  
Pavement Temperature

Road and highway maintenance is vital for the safety of citizens and for enabling emergency and security services to perform their essential functions. Accumulation of snow and (or) ice on the pavement surface during the wintertime substantially increases the risk of road crashes and can have negative impact on the economy of the region. Recently, road maintenance engineers have used pavement surface temperature as a guide to the application of deicers. Stations for road weather information systems (RWIS) have been installed across Europe and North America to collect data that can be used to predict weather conditions such as air temperature. Modelling pavement surface temperature as a function of such weather conditions (air temperature, dew point, relative humidity, and wind speed) can provide an additional component that is essential for winter maintenance operations. This paper uses data collected by RWIS stations at the City of Ottawa to device a procedure that maximizes the use of a data batch containing complete, partially complete, and unusable data and to study the relationship between the pavement surface temperature and weather variables. Statistical models were developed, where stepwise regression was first applied to eliminate those variables whose estimated coefficients are not statistically significant. The remaining variables were further examined according to their contribution to the criterion of best fit and their physical relationships to each other to eliminate multicollinearities. The models were further corrected for the autocorrelation in their error structures. The final version of the developed models may then be used as a part of the decision-making process for winter maintenance operations.Key words: winter maintenance, pavement temperature, statistical modelling, RWIS.

Surface air–soil temperature relationship and shallow soil thermal regime: a case study using a soil temperature observational dataset for Spain.

2021 ◽  
Author(s):  
Camilo Melo Aguilar ◽  
Fidel González Rouco ◽  
Norman Steinert ◽  
Elena García Bustamante ◽  
Felix García Pereira ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Soil Temperature ◽  
Air Temperature ◽  
Thermal Regime ◽  
Ground Surface ◽  
Surface Air Temperature ◽  
Environmental Variable ◽  
Chemical Processes ◽  
Strong Connection ◽  
Shallow Subsurface

<p>The land-atmosphere interactions via the energy and water exchanges at the ground surface generally translate into a strong connection between the surface air temperature (SAT) and the ground surface temperature (GST). In turn, the surface temperature affects the amount of heat flowing into the soil, thus controlling the subsurface temperature profile. As soil temperature (ST) is a key environmental variable that controls various physical, biological and chemical processes, understanding the relationship between SAT and GST and STs is important.</p><p>In situ ST measurements represent the most adequate source of information to evaluate the distribution of temperature in soils and to address its influence on soil biological and chemical processes as well as on climate feedbacks. However, ST observations are scarce both in space and time. Therefore, the development of ST observational datasets is of great interest to promote analyses regarding the soil thermodynamics and the response to atmospheric warming.</p><p>We have developed a quality-controlled dataset of Soil Temperature Observations for Spain (SoTOS). The ST data are obtained from the Spanish meteorological agency (AEMET), including ST at different layers down to a depth of 1 m (i.e., 0.05, 0.1, 0.2, 0.5 and 1 m depth) for 39 observatories for the 1985–2018 period. Likewise, 2m air temperature has also been included for the same 39 sites.</p><p>SoTOS is employed to evaluate the shallow subsurface thermal regime and the SAT–GST relationship on interannual to multidecadal timescales. The results show that thermal conduction is the main heat transfer mechanism that controls the distribution of soil temperatures in the shallow subsurface. Regarding the SAT-GST relationship, there is a strong connection between SAT and GST. However, the SAT–GST coupling may be disrupted on seasonal to multidecadal timescales due to variations in the surface energy balance in response to decreasing soil moisture conditions over the last decade at some SoTOS sites. This results in larger GST warming relative to SAT. Such a response may have implications for climate studies that assume a strong connection between SAT and GST such as air temperature estimations from remote sensing products or even for palaeoclimatic analyses.</p>

scholarly journals Large area land surface simulations in heterogeneous terrain driven by global datasets: application to mountain permafrost

2013 ◽  
Vol 7 (6) ◽  
pp. 5853-5887 ◽  
Author(s):  
J. Fiddes ◽  
S. Endrizzi ◽  
S. Gruber
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Land Surface ◽  
Snow Depth ◽  
Ground Surface ◽  
Swiss Alps ◽  
Large Area ◽  
Heterogeneous Terrain ◽  
Ground Surface Temperature ◽  
Mountain Permafrost

Abstract. Numerical simulations of land-surface processes are important in order to perform landscape-scale assessments of earth-systems. This task is problematic in complex terrain due to: (i) high resolution grids required to capture strong lateral variability, (ii) lack of meteorological forcing data where it is required. In this study we test a topography and climate processor, which is designed for use with large area land surface simulation, in complex and remote terrain. The scheme is driven entirely by globally available datasets. We simulate air temperature, ground surface temperature, snow depth and test the model with a large network of measurements in the Swiss Alps. We obtain RMSE values of 0.64 °C for air temperature, 0.67–1.34 °C for non-bedrock ground surface temperature, and 44.5 mm for snow depth, which is likely affected by poor input precipitation field. Due to this we trial a simple winter precipitation correction method based on melt-dates of the snow-pack. We present a test application of the scheme in the context of simulating mountain permafrost. The scheme produces a permafrost estimate of 2000 km2 which compares well to published estimates. We suggest that this scheme represents a good first effort in application of numerical models over large areas in heterogeneous terrain.

scholarly journals Paleoclimatic reconstructions in western Canada from boreholetemperature logs: surface air temperature forcing and groundwater flow

2006 ◽  
Vol 2 (1) ◽  
pp. 1-10 ◽  
Author(s):  
J. Majorowicz ◽  
S. E. Grasby ◽  
G. Ferguson ◽  
J. Safanda ◽  
W. Skinner
Keyword(s):  
Surface Temperature ◽  
Groundwater Flow ◽  
Air Temperature ◽  
Ground Surface ◽  
Surface Air Temperature ◽  
Extreme Case ◽  
Western Canada ◽  
Surface Temperature Change ◽  
Minimal Impact ◽  
Western Canada Sedimentary Basin

Abstract. Modelling of surface temperature change effect on temperature vs.~depth and temperature-depth logs in Western Canada Sedimentary Basin show that SAT (surface air temperature) forcing is the main driving factor for the underground temperature changes diffusing with depth. It supports the validity of the basic hypothesis of borehole temperature paleoclimatology, namely that the ground surface temperature is systematically coupled with the air temperature in the longer term (decades, centuries). While the highest groundwater recharge rate used in the modelling suggests that for this extreme case some of the observed curvature in the profile, could be due to groundwater flow, it is more likely that the low recharge rates in this semi-arid region would have minimal impact. We conclude that surface temperature forcing is responsible for most of the observed anomalous temperature profile.

scholarly journals Large-area land surface simulations in heterogeneous terrain driven by global data sets: application to mountain permafrost

2015 ◽  
Vol 9 (1) ◽  
pp. 411-426 ◽  
Author(s):  
J. Fiddes ◽  
S. Endrizzi ◽  
S. Gruber
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Land Surface ◽  
Snow Depth ◽  
Ground Surface ◽  
Data Sets ◽  
Large Area ◽  
Heterogeneous Terrain ◽  
Ground Surface Temperature ◽  
Mountain Permafrost

Abstract. Numerical simulations of land surface processes are important in order to perform landscape-scale assessments of earth systems. This task is problematic in complex terrain due to (i) high-resolution grids required to capture strong lateral variability, and (ii) lack of meteorological forcing data where they are required. In this study we test a topography and climate processor, which is designed for use with large-area land surface simulation, in complex and remote terrain. The scheme is driven entirely by globally available data sets. We simulate air temperature, ground surface temperature and snow depth and test the model with a large network of measurements in the Swiss Alps. We obtain root-mean-squared error (RMSE) values of 0.64 °C for air temperature, 0.67–1.34 °C for non-bedrock ground surface temperature, and 44.5 mm for snow depth, which is likely affected by poor input precipitation field. Due to this we trial a simple winter precipitation correction method based on melt dates of the snowpack. We present a test application of the scheme in the context of simulating mountain permafrost. The scheme produces a permafrost estimate of 2000 km2, which compares well to published estimates. We suggest that this scheme represents a useful step in application of numerical models over large areas in heterogeneous terrain.

scholarly journals Engineering Meteorology: The Effects of Weather and Climate on Concrete Pavement1

1959 ◽  
Vol 40 (10) ◽  
pp. 512-518 ◽  
Author(s):  
Fred V. Brock
Keyword(s):  
Surface Temperature ◽  
Concrete Pavement ◽  
Frost Heave ◽  
Freezing Process ◽  
Bearing Strength ◽  
Pavement Surface ◽  
Weather And Climate ◽  
The Common ◽  
Differential Frost Heave ◽  
Loss Of Strength

Concrete pavement may be adversely affected by weather and climate through the freezing process either within or under the pavement. The common results of freezing action that are detrimental to the durability and usefulness of the pavement are differential frost heave, loss of subsoil bearing strength, migration of subsoil, loss of strength of the concrete itself, and scaling of the pavement surface. Temperature and moisture are the dominant factors in each of these effects.

scholarly journals Spatio-Temporal Variations of Soil Active Layer Thickness in Chinese Boreal Forests from 2000 to 2015

2018 ◽  
Vol 10 (8) ◽  
pp. 1225 ◽  
Author(s):  
Xiongxiong Bai ◽  
Jian Yang ◽  
Bo Tao ◽  
Wei Ren
Keyword(s):  
Surface Temperature ◽  
Layer Thickness ◽  
Active Layer ◽  
Air Temperature ◽  
Climate Warming ◽  
Boreal Forests ◽  
Ground Surface ◽  
Active Layer Thickness ◽  
Ground Surface Temperature ◽  
Spatio Temporal

The soil active layer in boreal forests is sensitive to climate warming. Climate-induced changes in the active layer may greatly affect the global carbon budget and planetary climatic system by releasing large quantities of greenhouse gases that currently are stored in permafrost. Ground surface temperature is an immediate driver of active layer thickness (ALT) dynamics. In this study, we mapped ALT distribution in Chinese boreal larch forests from 2000 to 2015 by integrating remote sensing data with the Stefan equation. We then examined the changes of the ALT in response to changes in ground surface temperature and identified drivers of the spatio-temporal patterns of ALT. Active layer thickness varied from 1.18 to 1.3 m in the study area. Areas of nonforested land and low elevation or with increased air temperature had a relatively high ALT, whereas ALT was lower at relatively high elevation and with decreased air temperatures. Interannual variations of ALT had no obvious trend, however, and the ALT changed at a rate of only −0.01 and 0.01 m year−1. In a mega-fire patch of 79,000 ha burned in 2003, ΔALT (ALTi − ALT2002, where 2003 ≤ i ≤ 2015) was significantly higher than in the unburned area, with the influence of the wildfire persisting 10 years. Under the high emission scenario (RCP8.5), an increase of 2.6–4.8 °C in mean air temperature would increase ALT into 1.46–1.55 m by 2100, which in turn would produce a significant positive feedback to climate warming.

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