Terror as train carriage submerged in China floods. Image source, EPA. There has been some flooding, but people were out on the streets of Shanghai on Sunday. This video can not be played To play this video you need to enable JavaScript in your browser. Related Topics. China Severe weather. Develop a safety mind-set. During the storm If you are unable to evacuate your home and you are in a place that is vulnerable to flooding, make sure to stay on the second floor. Check tropical storm advisories from the Japan Meteorological Agency.
Stay away from downed power lines. When exposed to water, electric facilities such as power switchboards and power lines could cause not only a power outage but also the hazard of electric shock. Poland-Belarus border: What you need to know about the crisis.
Most Read. Belarusian airline stops flying Middle East citizens from Turkey. Should nations go nuclear to save the planet? Is Iran losing some of its grip on Shia militias in Iraq? The latent heat released increases the buoyancy of the cloud and provides the energy for the sustenance of the tropical cyclone circulation. In view of the vigorous ascent of air, the clouds formed around the "eye" have large vertical extent with tops reaching beyond 12 kilometers above the surface.
Such massive cloud formation produces heavy rains with large-sized raindrops. At the top of the storm system, the rising warm air is transported outward and form an anvil-shaped cloud called "cumulonimbus". Further away from the center, at the tip the air becomes colder and dry and starts "sinking" downward. In this area, which is outside the storm system, the weather is abnormally good. This is the basis for the saying "lull before the storm" which many perceptive people notice before the arrival of the storm.
Tropical cyclone constitutes one of the most destructive natural disasters that affects many countries around the globe and exacts tremendous annual losses in lives and property.
Its impact is greatest over the coastal areas, which bear the brunt of the strong surface winds, squalls, induced tornadoes, and flooding from heavy rains, rather than strong winds, that cause the greatest loss in lives and destruction to property in coastal areas. A squall is defined as an event in which the surface wind increases in magnitude above the mean by factors of 1.
The spatial scales would be roughly 2 to 10 km. The increase in wind may occur suddenly or gradually. These development near landfall lead to unexpectedly large damage. Tornadoes are tropical cyclone spawned which are to expected for about half of the storms of tropical storm intensity.
These are heavily concentrated in the right front quadrant of the storm relative to the track in regions where the air has had a relatively short trajectory over land. These form in conjunction with strong convection. Rainfall associated with tropical cyclones is both beneficial and harmful. Although the rains contribute to the water needs of the areas traversed by the cyclones, the rains are harmful when the amount is so large as to cause flooding.
The storm surge is an abnormal rise of water due to a tropical cyclone and it is an oceanic event responding to meteorological driving forces.
Potentially disastrous surges occur along coasts with low-lying terrain that allows inland inundation, or across inland water bodies such as bays, estuaries, lakes and rivers. For riverine situations, the surge is sea water moving up the river. A fresh water flooding moving down a river due to rain generally occurs days after a storm event and is not considered a storm surge. For a typical storm, the surge affects about km of coastline for a period of several hours.
Tropical cyclones owe their existence to the release of latent heat in intense convection. This convection depends on eddy transfers of heat, moisture and momentum at the sea surface and radiative effects, as well as on the tropical-cyclone-scale circulation itself. The relationship between the ocean and the atmosphere during tropical cyclone conditions is not a one-way interaction.
The stress exerted by strong winds on the surface water and the negative pressure anomaly leads to a rise of mean sea level under the storm of about 1 cm per mb of pressure drop. This mound of water follows the storm and contributes to the storm surge when the hurricane makes landfall.
The strong winds generate surface waves with amplitudes of 20 m or more. The curl of the stress generates divergence in the upper layer of the ocean, producing regions of upwelling and downwelling. Turbulence is also generated in the ocean by the wind stress and this turbulence mixes warm surface waters with deeper cooler water.
As we know, the ocean is divided into an upper layer of constant in the vertical temperature and a lower layer in which the temperature decreases with depth. The upper layer is termed the mixed layer because the constant temperature in the vertical is maintained by vertical mixing.
Temperature across the interface thermocline between the mixed layer and the lower layer is depicted as discontinuous. The response of the ocean to the approaching storm. As the storm approaches, the increasing winds produce stronger turbulence and a deepening and slight cooling of the mixed layer. Outside the radius of maximum wind, the anticyclonic relative vorticity is associated with a stress field with negative curl.
Convergence is induced in the mixed layer and downwelling occurs, which also acts to deepen the mixed layer. As the radius of maximum winds passes, the vorticity becomes strongly positive, and a positive stress curl induces horizontal divergence of mixed-layer water and a strong upwelling.
Behind the storm, the reverse sequence of events occurs. In addition, imbalances between the current velocities and pressure field in the ocean lead to eddies which between the current velocities and pressure field in the ocean lead to eddies which persists far behind the storm. Since the eddy circulations in the ocean which are induced by tropical cyclones and the sea-surface temperature decreases may persist for many days after a storm's passage, the behavior of subsequent storms which cross the modified ocean surface may be affected, although the small area of significant sea surface temperature decreases makes a large influence unlikely.
0コメント