What Is A Storm Surge?
วันอังคารที่ 4 สิงหาคม พ.ศ. 2552
by Henry
| Posted in
Storm Surge,
Thunderstorm
A storm surge is a tide level change primarily brought about by a storm, particularly of the tropical cyclone ilk. In a storm surge, the sea level increases above and beyond the normal sea height, creating huge walls of water that can exacerbate the risks of the storm.
How a Storm Can Cause a Storm Surge
Storm surges can occur in the case of a storm, big or small. They are more likely, however, in a tropical cyclone type of storm. The storm has different results, each of which becomes a factor that influences the characteristics of a storm surge. All the following factors interact with each other to determine how high and how powerful a storm surge is going to be
Wind
The wind is the principal cause of a storm surge. The wind blows over the water and causes a surge of gigantic waves. The fact that the wind is moving in a spiral rotational direction reduces the sea water height downwind and increases the water height upwind. This causes the formation of the storm surge.
The force of the wind affects how powerful the storm surge waves are going to be. Its direction also determines where the storm surge is going to be directed to.
Pressure
Where there is low pressure, the water level is going to be higher because there's not much pressure to counteract the heightening tide level. Where there is more pressure, the water level is going to be more controlled. This means that at the center of the storm where the pressure is lowest, there is less to stop the effect of the wind and control the heightened sea level.
Rainfall
Rainfall usually accompanies tropical cyclones and other types of storms. The increased rainfall aggravates the situation because it increases the overall volume of water.
Other Factors that Affect a Storm Surge
Other factors can influence the storm surge formation by affecting how high and how powerful a surge storm is going to be.
High Tide
If a storm occurs during the high tide, the storm surge becomes even more of an issue. The moon's gravitational force heightens the sea water level and therefore encourages the occurrence of a storm surge. A high tide also makes it more difficult to assess if a storm surge is going to occur; scientists have no foolproof method of determining whether the heightened sea level can be attributed to the possibility of a storm surge or to the high tide alone.
Bathymetry
Bathymetry or the measure of the depth of the ocean at a period of time and the terrain of the ocean floor (whether the ocean floor drops off from the shore steeply or not) also affects the formation of a storm surge.
In simpler terms, the deeper the water, the lower the water height is going to be. However, a steep drop near the shore also encourages more powerful storm surges, probably because of the lesser distance the storm surge has to travel. On the other hand a long, sloping and shallow floor leading to the shore encourages high water levels but generally weaker storm surge waves.
How a Storm Can Cause a Storm Surge
Storm surges can occur in the case of a storm, big or small. They are more likely, however, in a tropical cyclone type of storm. The storm has different results, each of which becomes a factor that influences the characteristics of a storm surge. All the following factors interact with each other to determine how high and how powerful a storm surge is going to be
Wind
The wind is the principal cause of a storm surge. The wind blows over the water and causes a surge of gigantic waves. The fact that the wind is moving in a spiral rotational direction reduces the sea water height downwind and increases the water height upwind. This causes the formation of the storm surge.
The force of the wind affects how powerful the storm surge waves are going to be. Its direction also determines where the storm surge is going to be directed to.
Pressure
Where there is low pressure, the water level is going to be higher because there's not much pressure to counteract the heightening tide level. Where there is more pressure, the water level is going to be more controlled. This means that at the center of the storm where the pressure is lowest, there is less to stop the effect of the wind and control the heightened sea level.
Rainfall
Rainfall usually accompanies tropical cyclones and other types of storms. The increased rainfall aggravates the situation because it increases the overall volume of water.
Other Factors that Affect a Storm Surge
Other factors can influence the storm surge formation by affecting how high and how powerful a surge storm is going to be.
High Tide
If a storm occurs during the high tide, the storm surge becomes even more of an issue. The moon's gravitational force heightens the sea water level and therefore encourages the occurrence of a storm surge. A high tide also makes it more difficult to assess if a storm surge is going to occur; scientists have no foolproof method of determining whether the heightened sea level can be attributed to the possibility of a storm surge or to the high tide alone.
Bathymetry
Bathymetry or the measure of the depth of the ocean at a period of time and the terrain of the ocean floor (whether the ocean floor drops off from the shore steeply or not) also affects the formation of a storm surge.
In simpler terms, the deeper the water, the lower the water height is going to be. However, a steep drop near the shore also encourages more powerful storm surges, probably because of the lesser distance the storm surge has to travel. On the other hand a long, sloping and shallow floor leading to the shore encourages high water levels but generally weaker storm surge waves.
