Review and Critical Analysis of International UHI Studies

The following papers use a number of models to estimate the UHI impact on temperatures; air
quality & CO2 emissions; and energy use and peak power demand. The types of models used
have been described in more detail in the following paragraphs.
3.1.1 Temperatures
As temperatures are used to quantify the existence of an urban heat island they regularly appear
as a dataset for models and many simulations have temperatures as their outputs. Few look at
temperature specifically, rather the affects of albedo, buildings, reforestation on temperature.
Temperatures are modeled using meteorological models such as MM and CM.
A modeling study in Japan used a CM and a MM to calculate temperature variations in a city as a
result of the presence of buildings in the area. The data input for the MM in this study was from
a Grid Point Value Meso Scale Model, a weather prediction model used by Japan’s
Meteorological Agency. The CM’s components were wind velocity, potential temperature,
humidity, anthropogenic sensible and latent heat, surface heat budget for the walls of the
building and radiation/reflection from surfaces which is modeled only once because the
modeling is so complex [065].
3.1.2 Air quality & CO2 emissions
Seven studies focus on air quality specifically, of these seven studies two studies are from Asia,
four from North America and one from Europe. Some studies look at the urban heat island’s
effect on air quality [014, 139, 141] and some on mitigation strategies affect on air quality [013,
051, 050, 049]. The air pollutants focused on were Nitrogen Dioxide (NO2) Carbon Dioxide (CO2)
Carbon Monoxide (CO) Nitrogen Oxide (NOx) and Ozone (O3).
The meteorology models commonly used were MM, photochemical models were typically Urban
Air Shed Models for ozone, the Air Pollution Model (TAPM) for air pollution generally, and
Biogenic Emissions Inventory Systems (BEIS‐2) for biogenic emissions.
Haider Taha, originally at Lawrence Berkeley National Laboratory (LBNL) and now at
Altostratus, is a leader in the field of meteorological and air quality‐modeling and has written
many papers on the modeling of urban heat islands. In Taha’s 2008 paper he discusses the heat
island’s impact on air quality using uMM5 and CAMx models with particular reference to ozone.
The study also models albedo increase and its impact on air temperature. In this study Taha
considers the meso‐urban modeling of heat island mitigation superior to the mesoscale as it
produces impacts on air quality etc on a larger scale, and captures phenomena that a mesoscale
model would not have identified for example cool islands [049].
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