1. RH and UHI

2. Relative Humidity 7.76g 14.8g 27.69g

4. Urban Heat Islands  Effects first discovered in 19 th Century (why??)  First detailed by Chandler in 1965

6.  Mainly night time effect  City is on average 3-4 oC higher  Generally temperatures grow towards the inner city  Varies over different land uses –Parks etc –Density of buildings

7.  Purple = Richmond Park

8. Changes in UHI  Less Pronounced  (less pollution, clean air act 1956, catalytic converters in cars, electric trams, less coal used in homes)  Building materials (higher albedos)  City planning (density of buildings)  Less heavy polluting industry  CITY SIZE

9. Effects of UHI  Vegetation – flowering??  Heating and cooling systems  More time outside?? – pavement café’s

10. UHI – Los Angeles  1930 – area covered with orchards, ave summer temp 97 oF  1990’s av summer temp 105 oF