St. Andrews UHI experiment, May 6, 2008

St. Andrews seen from southeast May 6, 2008 hr.12:59.

The general weather situation, measurement equipment and measurement route

The weather was dry and partly overcast, with a high pressure spreading from NE across the North Sea. The wind was moderate from E, about 4-6 m/s. The ambient air temperature was about 15^oC. 

A thermistor mounted inside a radiation shield was attached to the roof of a car (c. 1.5 m above terrain), and temperatures were logged at 2 sec. intervals. The time given in the diagrams below and in the figure caption above is according to solar time (not corrected for summer time). The measurements were carried out for a route passing through the city from west to southeast, as shown by the map below.

St. Andrews is located at 56^o20'N 2^o50'W, on the east coast of Scotland. The present number of inhabitants is about 14,000 (2007). There is no official meteorological station located in St. Andrews; neither are there any major factories or heat generating industries located in St. Andrews. St. Andrews is on the other hand famous for the invention of golf and for having the famous University of St. Andrews, the oldest university in Scotland, third oldest in UK.

Map showing location of the measurement route (yellow). The map measures 12 km from west to east. The altitude ranges from 5 to 60 m asl., highest at the endpoints of the traverse.

Results

Result of temperature traverse May 6, 2008: Starting in rural landscape west of St. Andrews, passing through St. Andrews, and ending in rural landscape southeast of the town (see map above). The weather was partly overcast. Winds were moderate from E, and the relatively cold sea water influences the air temperature, especially in the eastern part of St. Andrews (see map above). The potential urban heat island is almost totally overridden by the cooling effect of the nearby sea. This is an analogue to the open water effect described from Longyearbyen, Svalbard, although here with opposite (cooling) effect. 

Interpretation

In western St. Andrews the onset of a urban heat island is suggested by the temperature reading, but a short distance further east this effect disappears, and relatively cold air masses moving onshore from the nearby North Sea dominates the temperature. In easternmost St. Andrews, near the coast, the recorded air temperature is about 12.8^oC, while further inland the temperature is 15.5-16.0^oC. The ocean cooling effect at the time of measurement was about 3^oC.