St. Andrews UHI experiment, June 11, 2008

St. Andrews seen from southeast June 11, 2008 hr.10:40.

The general weather situation, measurement equipment and measurement route

The weather was dry and partly overcast, with somewhat moister air moving in from NW (see photo above). The wind was moderate from NW, about 4-6 m/s. The ambient air temperature was about 17^oC. Because of the moving clouds, areas with cloud-induced shaddow were moving across the landscape in a south-easterly direction. 

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 June 11, 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 (see photo above), and winds were moderate from NW (4-6 m/s). The potential St. Andrews urban heat island is almost totally overridden by the effect of changing local conditions along the measurement route, between sunlit and shaddow, as indicated by the horisontal bar.

Interpretation

The temperature pattern recorded is dominated by local heating effects, controlled by changing conditions from sunlit to being in cloud shaddow. In western St. Andrews the onset of a urban heat island may weakly be suggested, but it is not possible to discriminate from sunlit-shaddow effects. The airflow was from NW, and there is therefore no local effect of the ocean, as was registered on May 6, 2008. The thermistor was positioned about 1.5 m above terrain, and the results suggests that shifting conditions between sunlit and shadow rapidly are felt several metres about the ground. Standard meteorological measurement height is 2 m.