urban thunderstorms

Question 1

urban heat island

Answer 1

urban areas being warmer than rural areas

Question 2

where are highest temperatures found?

Answer 2

industrial areas and in the most densely built up areas

e.g CBD

Question 3

absorption of heat by urban surfaces

Answer 3

concrete brick and tarmac surfaces absorb and store heat from the sun during the day
slowly release the heat as long wave radiation

Question 4

air poolution

Answer 4

increase cloud cover over the city
creates a pollution dome
trap outgoing heat radiation and reflect it back to the surface

Question 5

heat from human activities

Answer 5

cars factories offices central heating air conditioning units and people all release heat

Question 6

less evapotranspiration

Answer 6

when rains rater quickly removed by drainage systems so theirs little surface water to evaporate
not much vegetation so little transpiration
evapotranspiration uses heat energy so less evapotranspiration means higher temperatures

Question 7

what is evapotranspiration

Answer 7

transfer of water from earths surface to the air via evaporation and transpiration

Question 8

what happens to the rain in urban areas?

Answer 8

more rain and also more intense

more thunderstorms

Question 9

convectional uplift

Answer 9

air in urban areas is warm (UHI)
warm air can hold more water
warm moist air rises

Question 10

what happens as the air rises?

Answer 10

cools
water vapour condenses
rains
(convectional rainfall)

Question 11

dust and pollution

Answer 11

urban areas generate huge amount of dust and pollution
act as condensation nuclei (trigger water to condense around them)
encourages clouds to form rather than allowing warm moist air to disperse