Urban Climate

What is the urban heat island?

The ‘urban heat island effect’ describes the phenomenon that surface air temperature is usually higher in cities and towns than in the surrounding countryside. The temperature difference is particularly clear during night-time hours. Read more…

What is the boundary layer?

The atmospheric boundary layer is the part of the atmosphere that is directly influenced by the land surface. It stretches from the ground to typically between 50m and 2km. It plays an important role in driving weather variation and the dispersion of atmospheric pollution. Read more…

What does a lidar do?

Lidar technology works in a similar way to radar technology, the major difference being that instead of using radio waves to detect objects, the lidar uses light. In the atmospheric science application, the lidar is commonly used to provide measurements of wind speed and direction. Analysis of lidar measurements can also provide information on the depth of the atmospheric boundary layer. Read more…

Our Publications

Summaries of our research papers will be added soon. Meanwhile, a list of our publications is available here.

Glossary of Terms

Atmospheric Boundary Layer (ABL): The portion of the atmosphere directly influenced by the land surface. The ABL varies in height from around 50m up to 4km above the Earth’s surface. It is typically 200m to 2km in depth and has a daily cycle of lower depth overnight and higher depth during the day.

LiDar: A remote sensing technique that takes measurements by sending out a laser beam of light and then measuring the frequency of the backscattered light. It can be used to measure complex wind turbulence profiles within the atmospheric boundary layer.

Remote sensing: Measurements taken from a distance for example; satellite observations or observations of the atmosphere taken from the ground.

SoDar: A remote sensing technique that takes measurements by sending out a pulse of sound and then measuring the frequency of the backscattered sound. It can be used to measure complex wind turbulence profiles within the atmospheric boundary layer.

Surface roughness: A measure of how ‘rough’ a surface is. The higher the surface roughness, the greater a barrier that surface represents to oncoming winds and therefore the larger the chance of increased turbulence.

Urban Heat Island (UHI) effect: Describes the observation that urban areas are typically hotter than their rural counterpart. This temperature difference is strongest overnight.

Urban Meteorology: The science of the atmosphere above urban land surfaces.

Urban Microclimate: The distinct atmospheric characteristics of an urban area. The atmosphere above an urban surface has very different wind and heat profiles than over other surfaces due to the increased roughness due to buildings and the influence of human activities such as pollution and heat emissions.