Std.7 sst ch.1 question answer

2 . If the Himalayas did not exist     If the Himalayas did not exist, India would be very different. The cold winds from Central Asia would enter India freely, making the climate much colder and drier. Many rivers like the Ganga, Yamuna, and Brahmaputra might not exist because these rivers originate from the Himalayan glaciers. Without the Himalayas, there would be less rainfall, fewer forests, and farming would become difficult in many regions. The northern plains might even look like deserts. The Himalayas also protect India from strong winds and help in bringing monsoon rains, so life in India would be much harder without them. 3. Why is India called a ‘mini-continent’? India is called a “mini-continent” because it has great diversity in physical features, climate, culture, languages, and natural resources, just like a continent. It has mountains in the north, deserts in the west, plains in the center, plateaus in the south, and coastal regions on both sides. Different par...
Post a Comment

Cyclone

Cyclone


 A cyclone is a system of winds rotating counterclockwise in the Northern Hemisphere around a low pressure center.

Cyclogenesis is the development or strengthening of cyclonic circulation in the atmosphere. Cyclogenesis is an umbrella term for several different processes that all result in the development of some sort of cyclone. It can occur at various scales, from the microscale to the synoptic scale.

Extratropical cyclones begin as waves along weather fronts before occluding later in their life cycle as cold-core systems. However, some intense extratropical cyclones can become warm-core systems when a warm seclusion occurs.

Tropical cyclones form as a result of significant convective activity, and are warm core. Mesocyclones form as warm core cyclones over land, and can lead to tornado formation. Waterspouts can also form from mesocyclones, but more often develop from environments of high instability and low vertical wind shear. Cyclolysis is the opposite of cyclogenesis, and is the high-pressure system equivalent, which deals with the formation of high-pressure areas—Anticyclogenesis.

A surface low can form in a variety of ways. Topography can create a surface low. Mesoscale convective systems can spawn surface lows that are initially warm-core. The disturbance can grow into a wave-like formation along the front and the low is positioned at the crest. Around the low, the flow becomes cyclonic. This rotational flow moves polar air towards the equator on the west side of the low, while warm air move towards the pole on the east side. A cold front appears on the west side, while a warm front forms on the east side. Usually, the cold front moves at a quicker pace than the warm front and "catches up" with it due to the slow erosion of higher density air mass out ahead of the cyclone. In addition, the higher density air mass sweeping in behind the cyclone strengthens the higher pressure, denser cold air mass. The cold front over takes the warm front, and reduces the length of the warm front. At this point an occluded front forms where the warm air mass is pushed upwards into a trough of warm air aloft, which is also known as a trowal.

Tropical cyclogenesis is the development and strengthening of a tropical cyclone. The mechanisms by which tropical cyclogenesis occurs are distinctly different from those that produce mid-latitude cyclones. Tropical cyclogenesis, the development of a warm-core cyclone, begins with significant convection in a favorable atmospheric environment. There are six main requirements for tropical cyclogenesis:

  1. sufficiently warm sea surface temperatures,
  2. atmospheric instability,
  3. high humidity in the lower to middle levels of the troposphere
  4. enough Coriolis force to develop a low-pressure center
  5. a preexisting low-level focus or disturbance
  6. low vertical wind shear.

An average of 86 tropical cyclones of tropical storm intensity form annually worldwide, with 47 reaching hurricane/typhoon strength, and 20 becoming intense tropical cyclones (at least Category 3 intensity on the Saffir–Simpson hurricane scale)



Comments

Post a Comment

Popular posts from this blog

Magic fingers art

Image
  Magic Fingers Art This is an amazing work like creativity with animated artistic easy drawing... If you have so much time to waste then do it and earn money. If your arts are awesome then do like this Don't waste your time just enjoy your artistic work with joy 😊 😊 😊 😊 
Read more

Humayun's Tomb

Image
Humayun's Tomb Humayun's Tomb is the tomb of the   Mughal Emperor   Humayun   in Delhi, India. The tomb was commissioned by Humayun's first wife and chief consort, Empress   Bega Begum   (also known as Haji Begum),   in 1558, and designed by Mirak Mirza Ghiyas and his son, Sayyid Muhammad,  Persian  architects chosen by her.   It was the first garden-tomb on the   Indian subcontinent ,   and is located in   Nizamuddin East , Delhi, India, close to the   Dina-panah   Citadel, also known as   Purana Qila   (Old Fort), that Humayun found in 1533. It was also the first structure to use red sandstone at such a scale.   The tomb was declared a   UNESCO World Heritage Site   in 1993,   and since then has undergone extensive restoration work, which is complete.   Besides the main tomb enclosure of Humayun, several smaller monuments dot the pathway leading up to it, from the main entrance in ...
Read more

Haunted place around the world

Image
  1. Château de Brissac, Maine-et-Loire, France Château de Brissac is a castle located in the commune of Brissac-Quincé, the department of Maine-et-Loire, France. The castle is recorded to have been built during the 11  th  century, and has a long and interesting history. Like many castles around the world, the Château de Brissac is said to possess its own resident ghost. This is the ‘la Dame Verte’ or Green Lady, who is said to be the ghost of an unfaithful wife murdered by her husband during the 15  th  century. Castle’s History Dubbed as the ‘tallest castle in France’, the Château de Brissac is said to have originally built as a castle by the Counts of Anjou during the 11  th  century. During the 15  th  century, the château was rebuilt as a fort-like structure by one of Charles VII’s ministers. During the French Wars of Religion, which broke out during the 16  th  century, the château was made into his possession by Henry of Nav...
Read more