EI Nino, Structure of Atmosphere, Extreme Weather Events, Thunderstorm

EI Nino

Under the condition, the water of the eastern pacific of equators, Peru, and the northern chill are surprisingly as cold as 10-degree centigrade, than the normal value of the water. This part of the eastern pacific is teeming with the fish, since the cold water which is rich in the nutrients. But once every 5 to 10 years from December to the March, the water of the eastern pacific warms up a little i.e 4 degrees higher than the normal values. When this disrupts the up willing of the cold water. This, in turn, disrupts the anchovy fishery key to the Peruvian economy. This phenomenon is called the EI Nino.

EI Nino is not a regular event as it takes place once every five years on an average. But when this phenomenon occurs, the local environment suffers from the enormous disruption. The anchovy fish die for the shortage of the food. This has the very critical effect on the Peruvian economy. Normally, the trade wind blowing the equator from the most south pacific toward the west pushes the warm water out of the sea. When EI Nino comes along the trades wind become weak and change the direction from west to east i.e the warm pacific ocean currents starts to flow east. When this reaches to the south America coast it kills the cold water fishes. The warm water also warms the air, which lowers the atmospheric pressure and sparks torrential storms along the Chilli coast reaching as far as southern California thus change the rainfall pattern due to the weak low pressure and leads to extensive drought and heavy floods in the other parts of the world.

Structure of the atmosphere

Atmosphere mainly consists four layers. They are troposphere, the stratosphere, mesosphere, and ionosphere. The short description of the four types of layer as follows:

1: Troposphere:

This layer is the basal part of the atmosphere which is about up to the 20km, above the earth surface is known as the troposphere. For the living organism, this layer is the most important layer of the atmosphere. The various kinds of the important events such as cloud formation, lightening, thundering, thunderstorm formation et.c all take place in the troposphere.

2: Stratosphere:

Just next to the troposphere, the second layer of about 30km height is called the stratosphere, where the temperature values show an increase up to the 90-degree centigrade. This increase in the temperature values is due to the ozone formation under the influence of the ultraviolet component of the sunlight. The upper layer of stratosphere forms the stratopause.

3: Mesosphere:

About 40 km in the height the layer next to the stratosphere is the mesosphere. In this zone, temperature shows again a decrease up to 80-degree centigrade. The upper layer of this zone is mesosphere.

4: Ionosphere:

The rest of the above the atmosphere up to the height of above 300km above the earth surface is called the ionosphere layer. Most of the gaseous components which have become ionized under the influence of the radiant energy remain as ions. Due to their much less density, they are relatively present in the molecular form.

Extreme weather events

Extreme weather includes the unusual, severe or unseasonal weather. Weather at the extremes of the historical distribution the range that has been seen in the past. The most commonly used definition of the extreme weather is based on an events climatological distribution: extreme weather occurs only 5% or lead at the time. According to the climate scientist and the meteorological researchers, extreme weather events have been rare. An increase in the extreme weather events has been attributed to man- made global warming. With a 2012 study indicated an increasing threat from the extreme weather.

Thunderstorm

A thunderstorm is also known as an electrical storm, a lightning storm, thundershower or simply a storm is a form of turbulent weather characterized by the presence of the lightning and its acoustic effect on the earth's atmosphere is known as the thunder. The meteorologically assigned cloud type associated with the thunderstorm is the cumulonimbus. A thunderstorm is usually accompanied by strong winds heavy rain and sometimes snow, hail, sleet or no precipitation at all. Those that causes the hail to fall are known as the hailstorm. A thunderstorm may line up in a series or rainband known as a squall line. Strong or severe thunderstorms may rotate, known as the super cells. While most of the thunderstorm move with the mean wind flow through the layer of the troposphere that they occupy, vertical wind shear cause a deviation in their curse at a right angle to the wind shear direction.

Thunderstorm results from the rapid upward movement of warm moist air. They can occur inside warm moist air masses and at fronts. As the warm, moist air moves upward, it cools, condenses and forms the cumulonimbus clouds that can reach heights over 20km. As the rising air reaches its dew point, water droplets, and the ice form and begins falling the long distance through the clouds towards the earth surface. As the droplet fall, they used to collide with the other droplets and they obtain the maximum size. The falling droplets create a downdraft of air that spreads out the earth surface and causes strong winds associated commonly with thunderstorms.

The thunderstorm can generally form and develop in any particular geographic location. Perhaps most of the frequently within the areas located at the mid-latitude when warm moist air collides with the colder air. A thunderstorm can generally form and are responsible for the development and the formation of severe weather phenomena. Thunderstorms and the phenomena that occur along with them, pose great hazards to the populations and the landscapes. The damage that results from the thunderstorms is mainly inflicted but the downburst winds, large hailstones and flash flooding caused by the heavy precipitation. Stronger thunderstorm cells are capable of producing tornadoes and the water spouts. A 1953 study found that the average thunderstorm over several hours expends enough energy to equals 50 A-bombs of the type that as dropped on the Hiroshima, Japan during second world war two.

There are mainly four types of the thunderstorm. They are the single cell, multicell cluster, multicell lines and supercells. Supercells thunderstorms are the strongest and the most associated with severe weather phenomena. Mesoscale convection system formed by the favourable vertical wind shear within the tropics and the subtropics are responsible for the development of the hurricanes. A dry thunderstorm with no precipitation can cause the outbreak of the wildfires with the heat generated from the cloud to ground lightning that accompanies them. Several methods are used to study thunderstorm such s weather radar, weather stations, and video photography. Past civilizations held various myths concerning thunderstorm and their development as late as the 18^th century. Other than within the earth atmosphere thunderstorms have also been observed on the Jupiter and Venus.

References:

.S.C., Santee. Environmental Science. India, New Center: New Center Book Agency (P) Ltd, 2004.

Lal, D.S. Climatology, Sharda Pustak Bhawan, Allahabad.(2010)