Mausam ka rahasya: The winds flowing in the atmosphere of the Earth seem as normal as they seem as complicated and effective. Some of these winds flow at a high speed, at a height of about 9 to 16 kilometers above the surface of the earth. We call them ‘jet stream’ or ‘jet streams’. It is not a normal air, but it is a type of highly high -speed practical river that affects even the weather, climate and flights of aircraft. Scientists also call them the ‘invisible tornado’ of the earth because they have a huge impact without appearing.
Let us know that after all this is a jet stream?
What is jet stream?
Jet Stream is a rapidly flowing narrow vesic stream that is found on the border of the upper atmosphere of the Earth, especially the troposphere and stratosphere. These currents are much faster than normal winds, which usually ranges from 150 to 400 km per hour. Whereas under certain circumstances, their speed has also been recorded up to 500 km per hour. Jet streams flows mainly from west to east, but their direction and speed changes from time to time according to the weather, change in temperature and the movement of the earth (coroolis effect). They are constructed due to the rapid difference of temperature in different regions of the Earth and the rotating speed of the Earth, especially where there is a collision of warm and cold winds such as on the Polar Front. Jet streams not only control the weather system but also have a profound effect on monsoon, cyclones and air travel.
Major types of jet stream
Jet streams are mainly identified in two major types.
Polar Jet Stream – Polar Jet Streams are located between 50 ° to 70 ° latitude in the northern and southern hemispheres of the Earth, where they flow near the polar regions. These jet streams are considered to be the most effective due to their rapid speed and powerful flow, especially in winter season, when the temperature difference in different parts of the Earth is high. They are mainly found at an altitude of 7 to 12 kilometers and are produced at the meeting site of cold and hot air masss. This is the reason why these weather plays play an important role in giving direction to the systems, shaping storms and bringing seasonal changes.
Subtropical Jet Stream – Subtropical jet streams are found around 30 ° latitude in both hemispheres and flow at a relatively high height i.e. at a height of 10 to 16 kilometers. Their speed is usually about 150 kilometers per hour. These jet streams especially affect the climate of tropical and subtropical regions and their effects are most seen in winter and early spring. This vessel stream plays an important role in the global weather system and sometimes helps in giving rise to conditions such as drought or heavy rainfall.
How do jet streams are formed?
The rapid difference of temperature and coriolis effects are two major causes in the manufacture of jet streams. The temperature is high when the sun rays near the equator are straight, while the temperature in the polar areas is very low. This temperature difference produces an imbalance in air pressure in the upper atmosphere. The hot air rises lightly and the cold air falls down due to heavy, causing rapid flowing winds in the atmosphere, which are called jet streams. These currents are mainly formed in areas where the difference between temperature and pressure is highly such as the Polar Front where cold and hot winds collide. On the other hand, the coriolis effect caused by the rotating motion of the Earth flows these jet streams from west to east. This effect does not keep their path straight and makes it wavy or curved which is called ‘Rossby waves’. This curved flow makes special contribution to shaping the weather system.
Jet stream effect on weather
The effect of jet streams is extremely wide and deep on the weather system. These currents set the boundary between warm and cold winds, which determines what kind of air will enter an area. When the jet stream bends towards the north, the hot air moves north and when it bends towards the south, the cold air comes downwards. In this way, the fluctuations of jet stream can change the weather of a place suddenly. Jet stream in India also plays an important role in the subtropical jet stream, the arrival and departure of the monsoon. If this section moves to north on time, then the monsoon comes on time. While the monsoon also comes late due to its delay, it has also been considered by the Indian Meteorological Department.
Apart from this, jet streams also affect the direction and intensity of cyclones and tornadars. When these winds rise at a rapid pace, the storm and tornado can not only become more powerful but can also change their direction. On the other hand, if the jet stream becomes stable or adopts a highly wavy path, then the weather in an area can remain the same for a long time. For this reason, regions like America and Europe sometimes have long-term cold wave or heat wave conditions.
Importance of jet stream in plane trips
Jet streams are used not only in meteorology, but also in the aviation industry. Pilots and airlines companies especially make the journey more efficient by taking advantage of the jet stream in long distance international flights. When the planes fly from the west to the east from New York to London, they take advantage of a fast -paced tailwind (backward air) of a jet stream. Which increases the speed of flight and as a result saves both time and fuel. At the same time, when the same aircraft flies from London to New York in east to west, it has to face the headwind coming from the front. Due to which the speed of flight slows down and the journey takes more time and fuel. For example, the flight from New York to London can arrive on average 30 to 40 minutes early if the jet stream is favorable. On certain special occasions, when the jet stream is extremely fast, the aircraft also succeed in reaching its destination in record time.
Climate change and jet stream
The effect of climate change is also clearly visible on the nature of jet streams. Due to global warming, the temperature is increasing rapidly in polar areas, especially in polar regions, due to which the temperature difference between the equator and the poles is gradually decreasing. This change directly affects the speed and route of the jet stream where these streams were fast and relatively straight, while now they are flowing at a slow pace and their path is becoming more wavy or curved. The result of this is that weather systems such as rain, drought, cold or heat can last longer in any area, which leads to an abnormal weather conditions.
Slow and stable jet streams may persistent heavy rain or long drought in some areas. Also, excessive cold or scorching heat waves can also remain frozen in one place for a long time. This instability of jet streams also affects cyclones. Their path and intensity may change, which can lead to more powerful and more powerful form. Unusual seasonal events seen in the US, Europe and Asia in recent years such as a severe flood of 2021 or continuous heat waves in the US are proof of this change. International climate scientific institutions such as IPCC have also clearly accepted this relationship.
Impact on India
The impact of jet streams in India is not only limited to monsoon but also has a direct impact on the climate of summer, cold and Himalayan regions. In the summer season, when the jet stream remains north side, especially above the Himalayas, the heat in most parts of India is intense. But when this stream moves towards the south, the cold winds enter the south, which can cause a sudden drop in temperature. This is the reason that in North India, sometimes during summer, sometimes cold waves or intense changes in the intensity of heat are seen.
In winter, jet streams are related to Western Disturbances which play a major role in the weather of North India. If the path of jet stream changes, it also changes the direction and strength of the western disturbances, causing rain and sometimes snowfall in winter. This rainfall is extremely important for rabi crops of North India, especially wheat.
In addition, the impact of jet streams can also be clearly seen on the Himalayan region. Due to these, sometimes unusual heat and sometimes unexpected cold are felt in the Himalayas. Which affects the melting rate of the glaciers there. This influence of jet streams has a profound impact not only on Himalayan ecology but also on the climate and agriculture of the whole of North India.
