Climate and seasons - class-X

El-Nino is a warm ocean current that sometimes appears off the coast of Peru in South America during the month of December. It increases the surface temperature of the sea and affects the movement of monsoon winds in the Indian Ocean and causes a drought-like situation in the Indian sub-continent. 

Air currents which determine the arrival and departure of monsoons are known as jet streams. These curents develop in the upper layers of the atmosphere. The westerly jet stream prevails over the North Indian plains during the winter months, while the easterly jet stream steers the tropical depression over India. 

El Nino is a Spanish word. It means "the Christ child". El
Nino is complex series of climatic changes which occurs irregularly. It affects
the equatorial Pacific region every few years. It is characterized by the
appearance of unusually warm, nutrient-poor water off northern Peru and Ecuador.
Reversal of wind patterns across the Pacific, drought in Australia, and non-seasonal heavy rain in South America are the effects of El Nino. It typically
occurs in late December, around Christmas. That’s why it is known as El Nino.

• Sun’s rays fall vertically on tropic of cancer on June 21st and as the tropic of cancer passes through India few cities receive sun’s rays vertically on June 21st. They include Ahmadabad, Bhopal, Ranchi.
  
• Mizoram do not receive sun’s rays vertically in June 21st. 
  

Dras is the coldest inhabited place in India and the second coldest inhabited place in the world. Dras is situated about 60 km away from kargil, on the road to Srinagar. The first village after Zoji La pass , Dras is situated at a height of 10,990 feet above sea level. In the freezing winter, temperature in Dras can drop to as low as -45 degree celsius.

The most important climatic control is latitude. Latitude affects the temperature of a place. The places situated at higher altitudes which are far from equator receive lesser sunlight and places which are located towards the equator which is a 0⁰ latitude receives more sunlight and are hotter than the places located at higher latitudes. Sunlight also affects precipitation or rainfall.

Thus latitudinal position of a regions decides the climate of the place.

Western disturbance is an extra tropical storm originating in Mediterranean Sea and that brings sudden winter rain to Indian subcontinent. These are one of the reason for cyclonic disturbances. Western disturbance are called by the name in India, Nepal, Afghanistan, Pakistan. 

• ITCZ stands for Inter-Tropical Convergence Zone. It is the area encircling the equator where the northeast and southeast trade winds come together. These are called as doldrums by sailors.
  
• In the Northern Hemisphere, the trade winds move in a southwestern direction from the northeast, while in the Southern Hemisphere, they move north-westward from the southeast. 
  
• These may cause hazards like thunderstorms.
  

The
periodic development of a warm ocean current along the coast of Peru as a
temporary replacement of the cold Peruvian current is known as El Nino. It is a
climate cycle in the Pacific Ocean with a global impact on weather patterns.
There is shift in direction and speed of wind during El Nino. Eastward Shifting
of warm water in the western tropical Pacific Ocean along the equator toward
the coast of South America marks the beginning of this cycle. Normally, this
warm water pools near Indonesia and the Philippines. But during an El Nino,
this warm water sit offshore of northwestern South America.

El Nina becomes La Nino when El Nino cools. La Nina is a counter ocean current which becomes effective in the Tropical Western Pacific when El Nino becomes ineffective in the Tropical Eastern Pacific. The dry condition in the western Pacific is terminated and the wet condition is introduced in the Tropical Western Pacific by Later Nina.

El Nino and La Nina refers to the periodic development of a warm and cold  ocean currents along the coast of Peru as a temporary replacement of the cold Peruvian current.

The hurricane impacts of El Niño and its counterpart La Niña are opposite and alternating between the Pacific and Atlantic oceans, strengthening hurricane activity in one region while weakening it in the other. However, the effect is limited to the climate of the tropics and subtropics.

Ocean currents does not have influence over the climate in India. Ocean currents act much like a conveyer belt, transporting warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics. Thus, currents regulate global climate, helping to counteract the uneven distribution of solar radiation reaching Earth's surface.

In Gujarat, unseasonable rain occurring during the winter or off-season is locally referred to as 'mavthu'.

Climate is influenced by various geographical factors, including latitude (solar intensity), altitude (temperature decrease with height), and distance from the sea (moderating effect).

The climate of India is primarily influenced by its location relative to the Equator, the presence of the Indian Ocean, and the seasonal monsoon winds. Ocean currents do not have a direct or significant impact on the climate of the Indian subcontinent compared to these other factors.