Indonesia Jet missing

• A jet carrying 62 people lost contact with air traffic controllers minutes after taking off from Indonesia’s capital Jakarta on a domestic flight on Saturday.

• Officials were examining debris found by fishermen to see if it was from the missing plane.
• The plane was carrying 50 passengers and 12 crew members, all Indonesian nationals.

Reason for the missing Indonesia jet: Thunderstorms

What are Thunderstorms?

• A lightning or electrical storm is known as a thunderstorm. It is characterized by lightning and thunder.
• Thunderstorms produce strong winds, heavy rainfalls, and even produce snowfall and hail. Some of thunderstorms don’t produce any precipitation and in some cases, thunderstorms produce very little precipitation.

How are Thunderstorms Formed?

• Cumulonimbus Clouds produce Thunderstorms and it forms when there is a rapid rise or movement of warm and moist air.
• Cumulonimbus clouds sometimes form at even heights of over 20 kilometres and it is formed when there is the upward movement of warm, moist air. This warm air and moist air cools and condenses when it moves upwards resulting in the formation of cumulonimbus clouds.
• Condensation of Water vapour into water droplets or ice happens when the rising air reaches its dew point temperature.
• This results in a reduction of pressure locally within the thunderstorm cell.
• Any precipitation falls a long distance through the clouds on the way to the surface of the Earth. Larger droplets are formed when the smaller droplets that are falling down collide with other droplets.
• Downdraft is created by the falling droplets as it pulls cold air with it, and this cold air spreads out at the surface of the Earth. This results in strong winds that are commonly produced during thunderstorms.

What are the 3 Stages of Thunderstorms?

Most Thunderstorms have three stages:

1) Cumulus Stage

• During day time the Earth’s surface gets heated up by the Sun.
• This results in Updraft, a phenomenon where warm air rises upwards. This happens due to the surface of the Earth getting heated up due to the Sun and the warm air is lighter than cool air, which results in its upward movement.
• The warm air condenses into a cumulus cloud in the presence of moist air.
• As long as warm air below the clouds continues to rise, it will help in the continuous growth of clouds.

2) Mature Stage

• The water in Cumulus Clouds becomes large and heavy as the cumulus cloud grows in size.
• Raindrops start to fall through the cloud when the rising air can no longer hold them up.
• Cool dry air starts to enter the cloud as the raindrops start falling through the clouds.
• The phenomenon of downdraft takes place. It is a phenomenon that happens when warm air is lighter than cool air, which makes the cool air to descend into the cloud.
• Heavy water is pulled downward by the downdraft resulting in rains.
• Due to updraft, downdraft, and rain; this cloud has become a cumulonimbus cloud.
• The cumulonimbus is now a thunderstorm cell.

3) Dissipating Stage

• Dissipation of thunderstorms happens after a time duration of 30 minutes.
• This dissipation occurs when the updraft gets dominated by downdrafts in the cloud. Due to this domination of downdraft cloud droplets will cease to form since the warm moist air can no longer rise. As the cloud disappears from top to bottom, the storm will dissipate.
• For ordinary thunderstorms, the above-mentioned complete process will take approximately 1 hour, whereas for much larger and powerful Supercell thunderstorms the above-mentioned dissipation process may take several hours.

About cyclones:

• A cyclone refers to any spinning storm that rotates around a low-pressure centre. The low-pressure centre is also referred to as the 'eye' of the storm, which is well known for being eerily calm compared with the areas under the spinning 'arms' of the storm.
• You could say that the eye is watching what's going on down below, so it needs a clear path, but the arms are where all the action happens because this is where the storm is throwing out all of its rain and wind.

How are cyclones formed?

• To form a cyclone, warm, moist air over the ocean rises upward from near the surface. As this air moves up and away from the ocean surface, it leaves is less air near the surface. So basically as the warm air rises, it causes an area of lower air pressure below.
• Air from surrounding areas with higher air pressure pushes in to the low pressure area. Then this new “cool” air becomes warm and moist and rises, too. And the cycle continues.
• As the warmed, moist air rises and cools the water in the air forms clouds. The whole system of clouds and wind spins and grows, fed by the ocean’s heat and water evaporating from the ocean surface.
• As the storm system rotates faster and faster, an eye forms in the centre. It is very calm and clear in the eye, with very low air pressure. Higher pressure air from above flows down into the eye.
• Tropical cyclones usually weaken when they hit land because they are no longer being “fed” by the energy from the warm ocean waters. However, they often move far inland, dumping many centimetres of rain and causing lots of wind damage before they die out completely.

Types of Cyclones:

• Tropical cyclones are what most people are familiar with because these are cyclones that occur over tropical ocean regions.
• Hurricanes and typhoons are actually types of tropical cyclones, but they have different names so that it's clear where that storm is occurring.
• Hurricanes are found in the Atlantic and Northeast Pacific, typhoons are found in the Northwest Pacific.
• If you hear 'tropical cyclone,' you should assume that it's occurring in the South Pacific or Indian Ocean, but for this lesson, we'll use it refer to all types of tropical ocean cyclones.
• We can also further describe tropical cyclones based on their wind speeds. They are called categories 1, 2, 3, 4 or 5, increasing with intensity and wind speed as the number increases. A category 1 cyclone is the weakest, with wind speeds of 74-95 mph. A category 5 cyclone, on the other hand, is extremely dangerous and has the potential for major damage. Category 5 cyclones have wind speeds of 155 mph and above!

• Polar cyclones are cyclones that occur in polar regions like Greenland, Siberia and Antarctica. Unlike tropical cyclones, polar cyclones are usually stronger in winter months. As you can see, these storms really do prefer the colder weather! They also occur in areas that aren't very populated, so any damage they do is usually pretty minimal.
• A mesocyclone is when part of a thunderstorm cloud starts to spin, which may eventually lead to a tornado. 'Meso' means 'middle', so you can think of this as the mid-point between one type of storm and the other. Tornadoes all come from thunderstorm clouds, but not all thunderstorm clouds make tornadoes. In order for a tornado to occur, part of that cloud has to spin, and though you can't really see this happening, this is the intermediate, or 'meso' step from regular cloud to dangerous spinning cloud running along the ground.

Depending upon its location and strength, a tropical cyclone is referred by different names:

• Typhoons in Western North Pacific
• Willy-willies in Australia
• Baguio in Philippine Islands
• Hurricanes around North America
• Taifu in Japan
• Cyclone in the Indian Ocean