The Effect of Increasing Surface Albedo on Urban Climate and Air Quality: A Detailed Study for Sacramento, Houston, and Chicago

Abstract

Increasing surface reflectivity in urban areas can decrease ambient temperature, resulting in reducing photochemical reaction rates, reducing cooling energy demands and thus improving air quality and human health. The weather research and forecasting model with chemistry (WRF-Chem) is coupled with the multi-layer of the urban canopy model (ML-UCM) to investigate the effects of surface modification on urban climate in a two-way nested approach over North America focusing on Sacramento, Houston, and Chicago during the 2011 heat wave period. This approach decreases the uncertainties associated with scale separation and grid resolution and equip us with an integrated simulation setup to capture the full impacts of meteorological and photochemical reactions. WRF-ChemV3.6.1 simulated the diurnal variation of air temperature reasonably well, overpredicted wind speed and dew point temperature, underpredicted relative humidity, overpredicted ozone and nitrogen dioxide concentrations, and underpredicted fine particular matters (PM 2.5 ). The performance of PM 2.5 is a combination of overprediction of particulate sulfate and underprediction of particulate nitrate and organic carbon. Increasing the surface albedo of roofs, walls, and pavements from 0.2 to 0.65, 0.60, and 0.45, respectively, resulted in a decrease in air temperature by 2.3 • C in urban areas and 0.7 • C in suburban areas; a slight increase in wind speed; an increase in relative humidity (3%) and dew point temperature (0.3 • C); a decrease of PM 2.5 and O 3 concentrations by 2.7 µg/m 3 and 6.3 ppb in urban areas and 1.4 µg/m 3 and 2.5 ppb in suburban areas, respectively; minimal changes in PM 2.5 subspecies; and a decrease of nitrogen dioxide (1 ppb) in urban areas.

Urban Cold and Heat Island in the City of Bragança (Portugal)

“…Sensible heat (SH) and latent heat (LH) also have a major influence on urban climate during the day in urban and rural areas, respectively [11,17,19,20]. Low albedo of surfaces also plays a relevant role in promoting the UHI effect [5,14,[17][18][19][20][21][22][23][24]. In addition, anthropogenic sources provide supplementary heat in cities [11,18,23].…”

Urban growth dynamics based on surface Albedo changes in Petrolina, Brazil

“…For rapid urbanization, as it can be observed in some Chinese cities, Hou, Hu, and He (2014) argue that dramatic urbanization always results in rapid changes to land surface properties, such as vegetation cover, albedo, and land surface temperature. Jandaghian and Akbari (2018) analyze the effect of increasing surface albedo on urban climate and air quality for three cities (Sacramento, Houston, and Chicago). The surface albedo is also very useful in Urban Heat Islands (UHI) studies (Hou et al, 2014;Fu & Weng, 2018;Jandaghian & Akbari, 2018).…”

“…Jandaghian and Akbari (2018) analyze the effect of increasing surface albedo on urban climate and air quality for three cities (Sacramento, Houston, and Chicago). The surface albedo is also very useful in Urban Heat Islands (UHI) studies (Hou et al, 2014;Fu & Weng, 2018;Jandaghian & Akbari, 2018).…”

Linking Heat Source–Sink Landscape Patterns with Analysis of Urban Heat Islands: Study on the Fast-Growing Zhengzhou City in Central China

“…The previous studies have widely investigated highly reflective cool surfaces and retro-reflective (RR) materials as new countermeasures to the UHI effect [75][76][77]. Several studies have also proved that increasing the surface albedo of building envelopes and urban paving in urban areas can readily decrease air temperature [78][79][80]. For Zhengzhou City, the establishment of green roofs, cool pavements, cool roofs, and urban gardens in regions should be encouraged [13,81,82].…”