How are land and sea breezes formed? How these affect the microclimate of the coastal areas? Explain.
The land breeze and sea breeze are result of heating differences between land and water bodies. These are mainly observed in the coastal areas. While land breeze is the movement of wind from land towards sea, sea breeze is the movement of wind from sea towards land.
Land and Sea Breeze formation
Land gets heated and cools faster than water. At night, land releases the heat quickly thereby lowering the surface temperature and developing a high pressure area over it. Contrary to land, water releases heat at comparatively lower speed, due to which a low pressure area develops over the sea. Because of this pressure difference developed over land and sea, winds move from land towards sea. This is called Land Breeze. On the other hand, during the day time, land gets heated up faster than water. Due to this the air above the land surface gets heated quickly and rises up thereby developing low pressure area over the surface. In comparison to land, water takes time to acquire the same temperature as there in land. Because of this the air over the sea surface is comparatively cooler and has high pressure than that over land. This pressure difference causes the movement of air from sea towards land called Sea Breeze.
Microclimate is defined as the climate of small area that generally differs from its surrounding area. The weather variables in a microclimate are temperature, rainfall, wind and humidity. Impact of land breeze and sea breeze on the microclimate of the coastal areas are:
- Land and sea breeze prevent extreme temperatures in the coastal areas
- These are also responsible for frequent precipitation in coastal and offshore areas.
- Coastal areas have higher relative humidity than inland areas due to sea breezes.
Land and sea breeze patterns greatly influence the fog distribution and prevent accumulation of atmospheric pollutants in coastal cities.