Land And Sea Breeze Facts
- Land breeze takes place at land in the night when the land has become cooler
- Sea breeze normally starts in the morning, a few hours after sunrise, when the solar radiation heats the boundary layer over land.
- Land and Sea breezes take place due to the contrast between land and sea surface Temperature
- The land breeze is usually strengthened by the southerly flow which flows ahead of a surface low-pressure cell to the west. However, a sea breeze is weaker and start later, or may not take place at all.
- The sea breeze is strengthened by a northerly flow such as when there is a surface low-pressure cell to the east, or an anticyclone approaching from the west and it starts earlier. However, under these conditions, the land breeze will be weaker, start later and may not occur at all.
- Night minimum temperature is higher when the north-westerly wind persists throughout the night.
What Are Land And Sea Breezes?
Land and sea breezes are types of local winds that occur daily on the sea coasts due to differences in the surface temperature of the sea and adjacent land. There is a complete reversal of wind direction of these coastal winds. The land and sea breezes systems are very shallow with an average depth of 1-2 km. Over the lakes, the height of circulation is less but can extend inland up to 100 mi (161 km) or manifest as local phenomena that quickly weaken with a few hundred yards of the shoreline.
In warm tropical areas, where there is a continuous intense solar heating (insulation)throughout the year, people leaving there experience stronger and regular breezes compared to higher latitudes. After the sunset, the temperature over the landmass cools quickly in comparison to the ocean. During that time, the high pressure prevails over the landmass. So, the air moves from the high-pressure area formed over the landmass towards the ocean.
No matter the temperature scale, during the daytime, the land temperature may increase by tens of degrees, while water temperature increases slightly or let say just less than half a degree. In General, water has a high heat capacity, this high heat capacity hinders the sudden changes in water temperature during the night and the land temperatures may increase by tens of degrees, and the water temperature remains relatively stable. Where the differences in the temperature between land and sea are greater, land breezes and sea breezes become stronger. Land and sea breeze patterns have a great influence on fog distribution and pollution accumulation or dispersion in the areas where they occur. However, they often result in a high level of humidity, high precipitation and may also lead to temperature moderation in coastal areas. Land and sea breezes are very common occurrences in summer in higher latitudes, but in the tropics, they occur throughout the year. Land and sea breezes are often very strong in some areas and most times strong enough to raise sand and dust and have the ability to reduce visibility.
A land breeze is defined as a cool gentle wind that blows towards the sea from the land during the night. However, the reverse of the sea breeze takes place at night. This is rapidly heated up in the day time and at night cools more rapidly than the sea so that cold and heavy air is formed thus giving rise to a high-pressure condition over the land and a low-pressure region is created on the sea. See more explanation on pressure belts
The air above both the land and water surfaces is generally warmed or cooled as a result of conduction taking place on both surfaces. During the day, however, the warmer land temperature results in a warmer, less dense and lighter air movement over the coastal region when compared with the adjacent air mass over the water surface. As the warmer air rises by convection, cooler air flows in from the ocean to take over the empty space. When there is the availability of sufficient moisture and instability on the land breeze,there is a likely chance for showers, or even thunderstorms to form over the water
A sea breeze similar to the land breeze, it is a very cool moisture-laden that blows from the sea during the day towards the land where it is low-pressure area. A sea breeze is a very gentle breeze, its velocity may reach maximum in the daytime; this ranges between 6-50 km per hour in the afternoon temperature differences and amount of uplifted air. It is important here to take note of the low-pressure condition of the land which is caused by the heating effect of the sun. During the day time, the land gets heated up more quickly than the sea. The heated air expands and becomes lighter and rises thereby creating a region of low-pressure. At this time, the sea remains comparatively cooler with higher pressure, therefore, the sea breeze automatically blows from the sea to replace the warm rising air on the land. The stronger the sea breezes, the greatest the thermal difference between the land and sea. Sea breeze mostly occurs in the early summer period when inland temperatures have started to increase and sea temperatures which typically lag behind the air temperature, are still relatively low
Differences between land and sea breeze
|Land Breeze||Sea Breeze|
|Land breeze occurs in the cool nights||Sea breeze occurs during warm sunny days|
|The wind blows from the land to the sea as the land breeze||The wind blows from the sea to the land as the sea breeze|
|The air over the land cools faster||Warmer air rises|
|When the land cools up faster than the surrounding sea, it creates relatively high- pressure on land.||When the land heats up faster and becomes warmer than the sea, the heated air rises resulting in a low-pressure area, whereas the sea is relatively cool and the pressure over the sea is relatively high.|
|A pressure gradient is created from land to sea||A pressure gradient is created from sea to land|
|The wind reaches its peak shortly before the sunrise||The wind reaches its maximum intensity in the afternoon|
|Land breeze helps fishermen to enter into the sea in the morning and stay there till mid-afternoon||Sea breeze helps fishermen to return from the sea after a good catch|
|Cooler air flows from the land out under the warmer ocean air||Cool air flows in under it to fill the area over the land|