MOCCA - home

The local climate in a city can be quite different compared with the surrounding countryside. The so-called urban heat island effect forms a well-known illustration. To study the urban differences over the city Ghent University initiated the MOCCA (MOnitoring the City's Climate and Atmosphere) project and installed a network of weather stations in the city.

Ghent's Urban Heat Island

Cities turn out to have an associated urban heat island, especially during clear and calm nights urban regions stay considerably warmer than the surrounding countryside. This is explained by the fact that:

built-up areas (e.g. parking lots) take up more heat than natural areas (e.g. meadow)
3D geometry of buildings trap the outgoing long wave radiation during night within the street canyon
there is less moisture in the city. This means there will be less evaporation, an energy consuming process, and thereby more energy is left for heating the air over the city
the wind speed is significantly lower over the city
human activities (e.g. transportation) result in extra anthropogenic heat release

Higher temperatures in the city may sound tempting, but there are some drawbacks. Persisting warm periods lead to heat stress and may cause health problems, especially for vulnerable groups (e.g. elderly people). Heat waves are known to be responsible for more deaths than any other meteorological phenomenon. Due to the heat island effect extra attention is needed in urban regions for heat stress.

UHI Gent Map — Average night-time temperature difference between Ghent and the surrounding countryside (based on the ALARO model - RMI). The measurement locations are shown.

MOCCA network of weather stations

Locations Gent Map — Different locations of the 6 weather stations: realtime 2m temperature measurements in Gent. More realtime measurements can be found via observations

To study the geographical variability of the local climate in Ghent 6 automatic weather stations are installed in the city. All stations are identical and this is important to obtain reliable data. The locations are chosen such that different urban environments (e.g. port, park,...) can be compared with the surrounding countryside. The stations will stay for 3 years at their location.

Why is Ghent University undertaking the MOCCA project?

There are different motivations for setting-up this measurement network:

the collected data will be used for scientific research
students (both at university and secondary school level) will use these data for projects, thesis research, STEM courses,...
the network will make citizens aware of the urban climate in their city