Examine the causes and effects of land and sea breezes in East 

Candidates are expected to:

• Define land and sea
• Identify the areas where they occur in East Africa.
• Factors of land and sea breezes.
• Causes and their effects ·
• Illustrate their answer

Land and sea breezes are local winds which occur in areas where land is lying in close proximity to a water body e.g. around the shores of Lake Victoria and the coastal areas of East Africa.

Land breeze blows from land to sea/lake and occurs during the night while sea breeze blows from the sea to the land and occurs during the day.

Factors of land and sea breezes

• Differences in specific heat capacity of land and sea.
• Mobility of water compared to solid land.
• Heat transmission through transparent water as opposed to opaque land.
• Differences in reflecting capacity of land and water.

Causes of land breeze (occurs during the night)

• Loss of terrestrial radiation at coastlands at night. Land cools faster than the seal water which retain much of its heat
• Water loses heat more slowly such that the air above it warms up.
• Low pressure is created over the warm sea and high pressure over the cold land.
• Cool air from the land under high pressure blows towards the sea to replace the rising air hence land breeze.

Causes of the sea breeze (occurs during du day).

• There is intense heating of land areas during the day.
• Land warms faster than the sea hence temperatures are high over the land and colder over the sea.
• Convective currents of warm air rise over the land and create low pressure at the surface.
• Cool and moist winds i.e. from sea replace the rising air i.e. from high pressure to low pressure on land.

Effects of land breeze

• Lowering the temperature over the
• This may lead to formation of foggy or misty conditions over the lake/sea which results in poor
• Dry condition on land because little or no rainfall is received
• It results into violent thunderstorm. Offshore/rainfall.
• It also results into high humidity in the sea/lake.
• There is also formation of cloud cover over the sea.

Effects of sea breeze.

• Lowering of temperature on land especially in the afternoons which results in poor visibility.
• On shore convectional rainfall is formed which is usually received in afternoons.
• It results into violent thunderstorm.
• It also results into high humidity on land.
• There is also formation of cloud cover over land.