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Hajj & 'Umrah Relations Department

Permits & Contractors Relations Section

Hajj & 'Umrah Relations Department

Permits & Contractors Relations Section

4

Storms & Lightning Their Causes,

Dangers,Precautions

Storms & Lightning Their Causes,

Dangers,Precautions

in a volatile manner (causing the sound of thunder).The Fourth TheorySpontaneous heating occurs in the air followed by the passage of lightning, causing thunder. Scientists have supported this theory, which is the most factual, since such vibrations in the air would be the actual source of thunder, i.e. after the hot air is generated by the passage of lightning and the temperature caused thereby reaches 60,000 degrees and the air pressure fluctuates between 10 and 100 atm. The area which is encompassed by lightning expands and diffuses as a result of the affected pressure and temperature. The resulting tension is expressed by both audible (sound) and thermal (heat) energy. The actual sound of thunder lasts less than a second, but remains longer for two reasons:o The length of the lightning's course, which is about 5,000 meters.o The sound originates from every part of the lightning, whether near or far.Thunderbolts and How to Protect Oneself from ThemTo avoid thunderbolts, one should adhere to the following safety standards during a thunderstorm:Inside a Buildingo Stay away from open windows and doors.o Do not use electrical devices.o Avoid taking a bath, using the phone, or touching an electric conductor.Outside a Buildingo Keep the car locked and do not touch any metal.o Do not stop beneath or near any tall tree or under a telephone or electrical pole.o Seek shelter in a low-lying place like a valley, cave, cavern, or base of a mountain.In a Foresto Seek shelter under small, thick trees or cultivated plants or a group of trees of equal height.In Watero Avoid swimming in large pools, lakes or in the sea.o Avoid fishing in the sea.In a Fieldo Avoid open metal wagons, motorbikes, and bicycles.o Lie down flat on the ground if you are in an open area.Lightning Rods

These are copper poles placed on top of buildings to act as the central point of attraction and absorption for charges emanating from clouds. The lower part is connected to an electrical wire that runs along the building’s extremity until it reaches a depth of more than three meters underground, where there is a metal net buried in a moist place. This way, the electric current of the bolt traverses the copper pole and the electrical wire into the earth, thus absorbing its threat and negating its dangers.Technical Specifications for a Lightning Rodo It must be firmly connected to the ground.o The pole must be a good conductor that does not rust.o The ground in which the metal net is buried must meet certain electrical specifications appropriate for this task.o Maintenance and discharge procedures must be carried out in case the lightning rod is exposed to repeated discharge processes. A meter can be placed on the lightning rod to count the number of times a strike has traveled from the rod to the ground.Conditions of Installing Lightning RodsA lightning rod cannot be installed in just any place; rather, you must study the area that needs to be protected from lightning, bearing the following in mind:o The type of area to be protected, e.g. a building, electrical devices, fuel tanks, telecommunication areas, and so on.o The size of the area in square meters.o Know the structural status of the area, to know whether or not it is possible to erect towers and tall pillars.o Know the direction of the wind in order to know the direction of the clouds.o How high the area is above sea level.o Know the amount of air pressure in the area.

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In cooperation with the Department of Civil Defense

Number of Civil Defense: Qatar (999) Saudi (998)

Hajj & 'Umrah Relations Department Permits & Contractors Relations Section

321

According to a rough estimate, there are different natural phenomena occurring each day in the clouds over our planet, resulting in about 8 million lightning bolts. This means that there are 93 lightning flashes every second around the globe on a daily basis.Statistics have shown that we are surrounded on all sides by storms, and these phenomena only occur in some places as a result of volatile climatic factors affected simultaneously by both hot and cold temperatures.Research conducted by some French scientists has established that this threatens the stability of their country on an average of 15 to 25 days in the year, unevenly distributed between the north and the south parts of the country.In order to understand these phenomena better, in this article, we will show the most important scientific explanations and analyses regarding their main characteristics, just as we present the most important preventive measures to avoid their dangers.Electrical StormsScientists have taken interest in storms for ages, in order to reach convincing explanations for their causes and courses. There are numerous studies and theories that revolve around the appearance of positive and negative electrical charges and the ways they are distributed and transported. The following are some of these theories:The First TheoryRain falls like pellets from a cloud due to gravity then they are centered on suspended drops of water and snow. There occurs an internal collision between these pellets and the suspended water droplets because of aerial movement and fluctuating currents, thus an electrical state originates in the cloud and gives rise to water droplets carrying positive charges upward while hailstones carrying negative charges travel to the bottom of the cloud. Consequently, the two charges, positive and negative, rush toward one another, whether within the same cloud or between two clouds, and this causes the storm to appear.The Second TheoryThis theory is somewhat complex as it considers that

electrical charges that exist inside the cloud come from different external sources, including:o Cosmic Rays: Electrical charges of this external source propel the water droplets above the cloud.o Electrical Field: This field consists of sharp objects found in the earth. When the electrical field's density rises, there occurs a process of stimulation and depositing; the hot aerial currents transfer positive electrical charges from the earth to the peak of the cloud to attract the negative charges, which enter the cloud and get attached to the droplets of water and snow. These negative charges form a barrier, and the electrical currents encompassing the cloud act on forming a positive binary structure opposite the established barrier.The Third TheoryThis theory is called the tri-polar theory which is used by meteorologists currently, after many tests and observations, to explain how positive and negative charges are transferred and how storms are formed.The cloud comprises an axial zone containing negative charges found between upper and lower zones; the positive charges are centered over the axial zone by about 6 kilometers. It is a few meters thick with a temperature equaling 15 degrees Celsius, so it is around 2 to 4 kilometers above the positive lower zone. This is in addition to a fourth zone formed at the top of the cloud that is thin and contains negative charges, which is a result of the deposit of water particles via radiation.LightningIt is the light that flashes through the sky as a result of the electrical field produced by the cloud's charges; its quantifiable value exceeds that of the atmospheric conditions, reaching 1 million volts per meter, just as the energy output is 6 billion watts per second. Lightning is normally produced in the mid-region of negative charges reaching upwards about 6,000 meters with a temperature of 15 degrees, originating inside the cloud. These are not the same as thunderbolts.ThunderboltA thunderbolt, or lightning bolt, is a fiery object that appears in the sky during a storm. It is a strong electrical spark, the temperature of which may scorch the earth and cause trees and buildings to burn, resulting in the loss of

life and property. The electrical energy generated from it disperses in the air and may hit planes flying in the sky. Scientists have confirmed that a thunderbolt results from a process of electrical discharge occurring between two clouds or between a cloud and the earth and that it forms whenever there is a large group of clouds.Electrical charges gather in the mid-region of the cloud, with high tension, cause the presence of opposite charges on the earth's surface, attracting them and establishing the discharging process. The size of the cloud increases when the difference of electrical potential difference reaches a high value that the surrounding air cannot bear. The voltage needed for the start of the discharge process is from 5 to 10 kilovolts per centimeter.The discharge process is completed with one or more impulses. Each impulse is called a "hop", so the first part of the discharge process is weak in intensity, in order to plot a course, which consists of descending aerial pathways which fork and diverge; whichever path is the nearest for these hops to reach the earth has the strongest electrical field, so sparks are emitted from high points on earth like tall buildings, trees, and antennae. Along this pathway, the electrical potential difference reaches some hundreds of millions of volts until an intense reverse current appears that exceeds 100,000 amperes, rising from the earth to the cloud, via the spark of discharge, to modify the charge inside the cloud.ThunderThere are four theories regarding the phenomenon of thunder. Their explanation is as follows:The First TheoryLightning causes a vacuum, which the thunder attempts to fill with the surrounding air (causing a sound).The Second TheoryA large quantity of water that blocks the path of lightning vaporizes. This results in a loud boom, which is the product of the quick expansion of water vapor produced.The Third TheoryThis theory explains that the electrical discharge resulting from lightning separates water particles, in accordance with the phenomenon called "electrolysis", into hydrogen and oxygen. These particles are returned