Trade Winds blow as northeast trade winds in the Northern Hemisphere and as southeast trade winds in the Southern Hemisphere. The trade winds are strongest on the eastern and equatorial sides of the major subtropical highs, especially over the Atlantic. Trade winds are principally caused by the Coriolis effect and Ferrel's rule. This article will provide you with information about the North-East Trade Winds with a UPSC Civil Service examination perspective in Geography.

North-East Trade Winds

• The prevailing east-to-west winds that blow in the equatorial region of the Earth are known as the trade winds or easterlies.
• The trade winds blow mostly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere, with the trade winds being stronger in the winter and when the Arctic oscillation is in its warm phase.

Northeasterly Trade Winds

• Since they blow from the northeast, they are known as the northeast trade winds in the northern hemisphere.
• Because they blow from the southeast, they're known as the southeast trade winds in the southern hemisphere.
• The trade winds do not immediately hit the equator. The rotation of the Earth causes them to be deflected.
• Trade winds are winds that blow from subtropical high-pressure areas to the equatorial low-pressure belt.
• As a result, they can only be found on the earth's surface between 30°N and 30°S.
• In their origin areas (subtropical high-pressure system), trade winds are descending and steady, but as they approach the equator, they become humid and warmer as moisture accumulates along the way.
• At the equator, trade winds from both hemispheres meet and, due to convergence, climb, causing heavy rainfall.
• As they are linked to cool ocean currents, eastern trade winds are drier and more consistent than western trade winds.

North East Trade Winds

Origin of NE Trade Winds

• During the cold season, trade winds originate more from the poles (northeast in the Northern Hemisphere, southeast in the Southern Hemisphere) and are stronger in the winter than in the summer.
• Due to the Coriolis Effect and an area of high pressure, the prevailing winds (the trade winds) move from east to west over this 60-degree "belt" on both sides of the equator.
• Surface air rushes in to replace warm, moist air as it rises along the equator, generating NE trade winds.

Difference Between SW and NE Trade Winds

Effects of NE Trade Winds

• When trade winds blow over warm tropical oceans, they collect moisture and give considerable rainfall to the windward-facing slopes of hilly places, in contrast to the downward passage of dry air that creates arid areas on land.
• As the air cools in the tropics, it descends, blowing from northeast to southwest as it approaches the equator.
• In a zone encompassing 5 degrees north and 5 degrees south latitude, the Northern and Southern Hemisphere trade winds collide.
• Ships can use these northeast trade winds to go west, as well as to steer storms such as hurricanes.
• There is essentially little wind right at the equator, which is known as the doldrums.
• The trade winds curl west in the Northern Hemisphere and east in the Southern Hemisphere due to the Earth's rotation.
• In a few parts of the world, the drying of plants, as well as dry skin and human lips, is caused by the North East Trade Winds.
• Aside from the dry air, these conditions do not produce rain, causing crop dryness.

North East Trade Winds in India

• The reversal of the South West Monsoon winds is known as the North-East Trade Winds.
• During the winter, the North-East Trade Winds are dominant in India.
• Since the northeast trade winds blow from land to sea, most of the nation stays dry.
• This explains why India's winters are so dry.
• A part of the northeast trade winds blows over the Bay of Bengal.
• As a result of the blowing winds, the Coromandel Coast may see some rain.
• Although the nights are very cold, the days are pleasantly warm.

Is NE Trades the Retreating Monsoon in India?

• As said earlier, the North East Trade Winds are the reversal of the South West Monsoon winds.
• The weakening of the heat low over North-west India kicks off the NorthEast Monsoon's dynamics.
• The power of the South-West monsoon winds begins to reduce as the low diminishes.
• Meanwhile, when the Sun moves south of the equator following the equinox on September 21, the interior of India, particularly Bihar, Jharkhand, and Bengal, cools swiftly.
• As a result, high-pressure regions form over the North Bay of Bengal and northern India.
• The winds are being pushed down south, towards India's southeast coast, by this high-pressure region.
• Following that, a U-shaped low-pressure trough forms across India's southern coast, which includes Kerala and Tamil Nadu.
• The winds from the high-pressure area in the North Bay of Bengal are pulled by this low-pressure trough, resulting in the North-East monsoon.
• This is known as a Monsoon Retreat because the wind direction and positioning of low and high-pressure zones are completely opposite that of the southwest monsoon season.

Significance

• For centuries, captains of sailing ships have relied on trade winds to navigate the world's waters.
• Every year, trade winds transport millions of tonnes of nutrient-rich Saharan dust across the Atlantic Ocean.
• They thus bring vital phosphorus and other nutrients and deplete the Amazon soils.

Types of Winds Winds are generally divided into four categories: Primary (Planetary) winds Secondary (Periodic) winds Tertiary (Local) winds Types of Winds Primary Winds The Primary winds are the winds that always blow in the same direction all through the year. They're also known as planetary winds or prevailing winds or persistent winds. These winds include Trade winds, Westerlies, and Polar Easterlies.

Conclusion

The trade winds are warmed and moistened by intense sun heat in the doldrums, which propels air upwards into the atmosphere like a hot air balloon. In the tropics and rainforests, when the air rises, it cools and generates prolonged bands of showers and storms. The rising air masses go to the poles before sinking back to Earth's surface at the horse latitudes. The cycle is completed when the sinking air causes calm trade winds and little precipitation.

FAQs

Q1: What are North-East Trade Winds?

Q2: Why are they called "trade winds"?

Q3: How do North-East Trade Winds affect India’s climate?

Q4: What is the significance of North-East Trade Winds in global circulation?

Q5: How are North-East Trade Winds different from South-East Trade Winds?

MCQs

1. From which direction do North-East Trade Winds blow?

a) North-West to South-East

b) North-East to South-West

c) South-West to North-East

d) South-East to North-West

2. During which season do the North-East Trade Winds predominantly affect India’s climate?

a) Summer

b) Winter

c) Monsoon

d) Spring

3. What is the primary cause of North-East Trade Winds?

a) Monsoonal circulation

b) Coriolis effect and subtropical high-pressure zones

c) Ocean currents

d) Solar radiation

4. Which region in India receives rainfall due to North-East Trade Winds?

a) Rajasthan

b) Tamil Nadu

c) Gujarat

d) Punjab

5. In which hemisphere do North-East Trade Winds operate?

a) Northern Hemisphere

b) Southern Hemisphere

c) Both hemispheres

d) Equator only

GS Mains Questions and Model Answers

Q1: Discuss the role of North-East Trade Winds in shaping the climatic conditions of the Indian subcontinent.

Answer: North-East Trade Winds play a significant role in determining the winter climate of the Indian subcontinent. Originating from the high-pressure areas in the subtropics, these winds blow towards the equator, bringing cool and dry air over northern and central India during the winter months. The trade winds prevent significant rainfall in most parts of the country, except for regions like Tamil Nadu, where the North-East Monsoon causes rainfall.
These winds influence temperature, humidity, and weather patterns across India. For example, in northern India, they lead to colder winters, while in southern coastal regions like Tamil Nadu, they bring moisture-laden winds that result in seasonal rainfall. Their impact is essential in understanding the seasonal variation in India’s climate and agricultural practices, particularly the dependence on winter rains in the southeast.

Q2: Analyze the significance of North-East Trade Winds in global atmospheric circulation and ocean currents.

Answer: North-East Trade Winds are a crucial component of global atmospheric circulation, forming part of the Hadley cell, a large-scale circulation pattern that redistributes heat from the tropics towards higher latitudes. These winds originate from subtropical high-pressure belts and flow towards the equatorial low-pressure region, playing a pivotal role in balancing the earth’s heat budget.
In addition to their impact on atmospheric conditions, North-East Trade Winds influence ocean currents, particularly the formation of the North Equatorial Current in the Atlantic and Pacific Oceans. This interaction between winds and ocean currents helps in the redistribution of heat across the globe, influencing weather patterns, rainfall distribution, and the climate of coastal regions. Trade winds are vital in maintaining the stability of the global climate and ensuring the flow of warm ocean currents towards the poles, balancing thermal differences between the equator and higher latitudes.

Q3: Evaluate the impact of North-East Trade Winds on agricultural practices in India.

Answer: The North-East Trade Winds have a notable impact on agricultural practices in India, especially in regions like Tamil Nadu, which receive rainfall during the northeast monsoon season. The winter season, influenced by these winds, brings dry conditions to most parts of northern and central India, resulting in the rabi cropping season, where crops like wheat, barley, and mustard thrive due to lower moisture levels.
However, in the southeast, the North-East Trade Winds pick up moisture over the Bay of Bengal and bring rainfall to Tamil Nadu and adjoining areas, allowing for the cultivation of paddy and other crops dependent on winter rains. The seasonality and direction of these winds are therefore crucial in determining crop patterns, irrigation needs, and overall agricultural productivity in various regions of India.

Previous Year Questions on North East Trade Winds

1. UPSC CSE 2016

Question: Discuss how the North-East Trade Winds affect the climate and agricultural patterns of Tamil Nadu. 

Answer: The North-East Trade Winds play a crucial role in determining the climate and agricultural patterns of Tamil Nadu. These winds, originating from the subtropical high-pressure areas, blow towards the Bay of Bengal and pick up moisture, resulting in rainfall during the northeast monsoon season (October to December). This rainfall is significant for Tamil Nadu, which receives most of its annual precipitation during this period.
The impact of these winds on agriculture is profound, as they provide the necessary moisture for crops like paddy, millets, and pulses, which are sown in the winter season. The agricultural calendar in Tamil Nadu is thus closely aligned with the arrival of the North-East Trade Winds, and farmers depend on these winds for irrigation and crop production. Without the rainfall brought by the trade winds, the region would face severe water shortages, affecting agricultural output and livelihoods.

2. UPSC CSE 2018

Question: Analyze the role of trade winds in the global ocean current system. 

Answer: Trade winds, including the North-East Trade Winds in the Northern Hemisphere and the South-East Trade Winds in the Southern Hemisphere, play a critical role in driving global ocean currents. These winds, due to their consistent direction and strength, push surface waters, creating major ocean currents such as the North Equatorial Current and the South Equatorial Current.
In the Pacific and Atlantic Oceans, the trade winds drive warm water westward, contributing to the formation of the equatorial currents. This movement of warm water towards the west and the return of cooler water through upwelling in the eastern parts of the oceans helps regulate global temperatures and weather patterns. The trade winds are integral to the functioning of the ocean-atmosphere system, influencing phenomena such as El Niño and La Niña, which have far-reaching impacts on global climate patterns, including rainfall and droughts in different parts of the world.