How to cause Typhoon Sandy 5

Formation of Typhoon Sandy.

In tropical or subtropical oceans with an ocean surface temperature of more than 26, due to the high near-ocean surface temperature, a large amount of air expands and rises, which reduces the near-ocean surface pressure, and the peripheral air continuously replenishes and rises inflow. Under the influence of the geostrophic deflection force, the incoming air rotates. When the rising air expands and cools, the water vapor in it cools and condenses to form water droplets, which releases heat and causes the low-level air to rise.

As a result, the near-ocean pressure drops lower, the air rotates more violently, and a typhoon is formed. Typhoons in the North Atlantic region are also called hurricanes.

The center of Hurricane Sandy in the North Atlantic at 14 o'clock on the 28th (Beijing time) is located about 450 kilometers east-southward of Cape Hatteras, North Carolina, USA, that is, north latitude and west longitude, with a maximum wind force of 12 (34 meters and seconds, equivalent to a typhoon in China) near the center, and a minimum pressure of 960 hPa at the center.

Typhoon Sandy was already a subtropical cyclone when it made landfall, and its energy was constantly consumed during the northward movement of Sandy, but due to its large size, it was slow to transform into an extratropical cyclone, and combined with cold air to cause a blizzard when it made landfall.

The cause of the typhoon is still uncertain, but it is known that it developed from disturbances in the tropical atmosphere. In the tropical ocean, the sea surface rises due to the direct sunlight and the temperature of the seawater, and the seawater is easy to evaporate into water vapor and disperse in the air, so the air temperature on the tropical ocean is high and the humidity is high, and the air expands due to the high temperature, resulting in a decrease in density and a decrease in mass, and the wind near the equator is weak, so it is easy to rise, and convection occurs, and at the same time, the surrounding colder air flows in and supplements, and then rises, so that the entire air column will eventually be the air with higher temperature, lighter weight and less density. This creates the so-called tropical depression. However, the flow of air is from high pressure to low pressure, just as water flows from high to low, and the air at the higher pressure around it must flow to the lower pressure, forming wind.

In summer, because the direct sunlight area shifts from the equator to the north, the southeast trade winds in the southern hemisphere cross the equator and turn into the southwest monsoon to invade the northern hemisphere, and meet the northeast trade winds in the original northern hemisphere, forcing the air to rise and increase the convection. The convergence caused by the meeting of the southwest monsoon and the northeast trade winds continues to interact with the original convection, so that the vortex that has formed into a depression continues to deepen, that is, the surrounding air accelerates the flow towards the center of the vortex, and the faster the inflow, the greater the wind speed. When the maximum wind speed near the surface reaches or exceeds 17.2 meters per second, we call it a typhoon.

How are typhoons formed?

A typhoon is a strong depression that rotates counterclockwise under the action of geostrophic deflection forces in the Northern Hemisphere, and the low pressure is accompanied by an upward motion. The typhoon initially formed a depression that was supposed to be Waka, and the cause of this was that there was too much local heating over the seawater, which produced hot air that moved upwards and formed a low-pressure system, and then continued to strengthen to form a powerful low-pressure system typhoon.

The typhoon structure sees that such a huge behemoth must have unique conditions for its generation. First, there must be a vast atmosphere of high temperature and high humidity. The temperature and humidity of the bottom atmosphere in the tropical ocean are mainly determined by the sea surface water temperature, and typhoons can only form on the warm ocean surface where the sea surface temperature is higher than 26 27, and the sea water temperature at a depth of 60 meters is higher than 26 27. Second, there should be an initial disturbance of the lower atmosphere converging to the center and the upper atmosphere spreading outward.

Moreover, the high-level divergence must exceed the low-level convergence in order to maintain sufficient updraft, and the low-level disturbance can continue to intensify. Third, the wind speed in the vertical direction should not be too different, and the relative movement of the upper and lower layers of air is very small, so that the latent heat energy released by water vapor condensation in the initial disturbance can be stored in the air column in the eye area of the typhoon, so as to form and strengthen the warm center structure of the typhoon. Fourth, there should be a sufficiently large geostrophic deflection force, and the earth's rotation is conducive to the formation of cyclonic vortices. The geostrophic deflection force is close to zero near the equator and increases towards the north and south poles, and typhoons occur over the ocean about 5 degrees above the equator.

There are certain conditions for the formation of typhoons. Therefore, its origin is also in a specific region. Typhoons are a "specialty" of the tropical ocean. It often occurs in the tropical ocean at latitudes of about 5 to 25 degrees north and south.

Northern Hemisphere typhoons mainly occur from July to October. Other seasons are significantly reduced. After the formation of a typhoon, it has a certain movement path.

Taking the Northwest Pacific typhoon as an example: in winter and spring (November to May of the following year), the typhoon mainly turns northward over the sea east of 130 degrees E, enters the central and southern parts of the South China Sea or makes landfall in southern Vietnam south of 16 degrees N, and a few turn northward in the offshore waters of 120 125 degrees E, and a few typhoons may also make landfall in Guangdong in May and November. In the midsummer of July and September, the typhoon's path shifts further north and west, and China's coastal provinces from Guangxi to Liaoning are likely to be hit by typhoons during this season. In the transitional season of June and October, typhoons mainly turn northward over the sea east of 125 degrees east of longitude, and the westward path is more northerly, between 15 and 20 degrees north latitude, and a few can make landfall in Guangdong, Taiwan, Fujian, and Zhejiang.

In addition to its rapid counterclockwise (northern hemisphere) rotation, typhoon movements are mainly guided by large-scale weather systems such as subtropical high and longwave troughs. Under normal circumstances, the typhoon's path is smooth and stable. However, the path of a few typhoons is tortuous and changeable, with various forms such as stagnation, rotation, sudden turn, sudden change in moving speed, and uncertain path drift.

The cause of typhoons is that the ground temperature is high and the air flow rises, and the sea surface wind and water vapor are heavy enough to replenish the ground air along the ground, and the sea surface temperature is low to absorb the air and water vapor rising from the ground to supplement the space. Due to the large sea surface and small temperature difference, there is a lot of water vapor that accumulates above the sea surface, and the rainfall is wide, and the volume of water vapor decreases when it condenses, and the surrounding water vapor replenishes to form a rising rotating air flow. The velocity of the air flow increases and increases, and finally a strong wind is formed.

When a typhoon comes, it is best to stay at home, when the wind is strong, close the doors and windows, and never open the windows and doors on the windward side to avoid strong air currents from blowing down the house. If you're out and about, be sure to watch out for tip-down objects on both sides of the road, such as fences, street trees, and billboards, which can pose a threat.

At the same time, pay attention to the following:

1. To prevent lightning strikes, it is necessary to quickly cut off the power supply of various electrical appliances. Close doors and windows tightly to avoid strong winds, and check and tie up objects that are easily blown by the wind, such as windows. If the glass is loose or cracked, please attach adhesive strips to the glass to prevent the debris from scattering after blowing.

Do not linger near glass doors and windows.

2. In the event of a typhoon, take shelter in a hut or cave, and if there is no such place, choose a safe place where there is no danger of landslides or floods, such as high ground, under rocks or in the forest. When you have to move forward, you should also bend down and do not rush into the rain, as damp clothes will take away your body temperature and cause an imbalance in your physical strength. In case of strong winds, try to lie on the ground and escape to the bushes, and do not hide under dead trees.

3. Do all the anchoring work. When the typhoon approached, the wind was fierce and the rain was pouring down. Families should take precautions in advance, such as moving flower pots on window sills or balconies to prevent them from falling.

At the same time, when a typhoon comes, it is easy for some large billboards to fall, trees to be blown down, and power poles to the ground......Therefore, it is best for the public not to go out when the typhoon comes, in case of smashing, crushing, electric shock and other accidents.

4. Listen to and watch the latest developments about typhoons published on radio, television, newspapers, meteorology, etc.

5. Citizens should prepare flashlights, candles, radios, food, drinking water and common medicines in advance, check whether the doors and windows are strong, remove hanging objects, check electrical circuits, stoves, gas, etc.

6. Residents should not go out at will, and ensure that the elderly and children stay in the safest place at home.

7. Power line safety, etc.: the unstoppable wind and rain make it difficult to survive the transmission line and broadcast line, and the inspection should be strengthened to prevent accidents such as electric shock.

1。Before a typhoon, prepare flashlights, radios, food, drinking water and medicines in case of emergency.

2。When a typhoon comes, please stay indoors in a safe place. If you are outdoors, please return to a safe and secure house as soon as possible, and watch out for falling objects such as fallen trees, flower pots, advertising signs, etc., on the road, and stay away from high-rise buildings with curtain walls.

3.Close the doors and windows and check whether they are sturdy; Remove the hanging thing; Check whether the electrical circuit, furnace, gas and other facilities are safe.

4。Move outdoor plants, animals and other items indoors, especially sundries on the roof; Outdoor things that are easy to blow should be reinforced.

5。Do not travel to areas where the typhoon passes, and do not swim on the beach or sail out on a boat during the typhoon.

6。People living in low-lying areas and dilapidated houses should be moved to safe accommodation in a timely manner.

7。Clean the drainage pipes in time to keep the drainage smooth.

The cause of the typhoon is that the ground temperature is high, the air flow rises, the sea surface wind and water vapor due to the large proportion, along the ground to supplement the ground air, the sea surface temperature is low to absorb the ground rising air, water vapor supplement space, due to the large sea surface, the temperature difference is small, the water vapor above the sea surface gathers more, the rainfall range is wide, the volume of water vapor shrinks when the water vapor is formed, and the surrounding water vapor is replenished to form rotating air.

There are several levels of typhoons: tropical depression, tropical storm, severe tropical storm, typhoon, severe typhoon, super typhoon.

A super typhoon is the highest level of typhoon, which means that the wind speed at the center of the typhoon has exceeded more than meters per second, and the typhoon scale is 16-18. The impact of super typhoons is extremely large, and the radius of the typhoon center is less than 500 kilometers. Typhoons are far more destructive than any natural disaster, causing dams to burst, roads to ruin, and buildings to be destroyed.

Serious can cause tsunami, flash floods and mudslides and other secondary disasters, direct economic losses of more than 100 million yuan.

Example: On November 4, 2013, Super Typhoon Haiyan No. 30 made landfall in the Philippines with a maximum wind of 315 km/h over the Philippines, Vietnam, Taiwan, coastal areas of China, and Indonesia. The typhoon killed about 7,000 people and caused direct economic losses of more than $700 million.