First-ever ‘space hurricane’ detected over the North Pole

In News –

For the first time, astronomers have detected a powerful, 600-mile-wide (1,000 kilometres) hurricane of plasma named space hurricane in Earth’s upper atmosphere.

Key Points –

• The space hurricane was detected on August 20, 2014, swirling hundreds of miles above Earth’s magnetic North Pole.
• The hurricane was invisible to the naked eye however, four weather satellites that passed over the North Pole detected a formation, not unlike a typical terrestrial hurricane.
• Using a 3D model of the hurricane, the researchers hypothesized that the formation resulted from a complex interaction between incoming solar wind (high-speed gales of plasma periodically released by the sun) and the magnetic field over the North Pole.
•  The phenomenon was noticed during a retrospective analysis led by the researchers at Shandong University in China.
  • The findings were published in Nature Communications in February this year.

What is Space Hurrincaene ‘?

• A ‘space hurricane’ is a swirling mass of plasma.
• It rains electrons directly into Earth’s upper atmosphere instead of water.
  • Hurricanes often cause loss of life and property through high winds and flooding resulting from the coastal storm surge of the ocean and the torrential rains.
• They are characterised by a low-pressure centre (hurricane eye), strong winds and flow shears, and a spiral arrangement of towering clouds with heavy rains.

Significance –

• The studies of space hurricane will help in understanding important space weather effects such as satellite drag, disturbances in high frequency (HF) radio communications, and errors in over-the-horizon radar location, satellite navigation and communication systems better.

Hurricanes:

• Hurricanes are enormous storms that come with a rotating wind speed of 74 miles per hour.
• The rotating wind swirls across the warm water of the tropics and comes with terrifying force.
• They are one of the most violent storms on earth and formed over the warm ocean waters near the equator.
• The term “hurricane” is usually used for the large storms that are formed over the Atlantic Ocean or the eastern Pacific Ocean.
• The first hurricane every year gets a name starting with the letter A, second with B, and so on.
• Depending on where they occur, hurricanes may be called typhoons or cyclones. They are given many names in different regions of the world:
  • Typhoons: tropical cyclones are known as Typhoons in the China Sea and the Pacific Ocean.
  • Hurricanes: In the West Indian islands in the Caribbean Sea and the Atlantic Ocean.
  • Tornados: In the Guinea lands of West Africa and southern USA.
  • Willy-willies: In north-western Australia and
  • Tropical Cyclones: In the Indian Ocean Region.

Mechanism of its formation:

• Low-Pressure Creation: When the warm, moist air rises upward from the surface of the ocean, it creates an area of low air pressure below. When this happens, the air from the surrounding areas rushes to fill this place, eventually rising when it becomes warm and moist too.
• An eye forms in the centre. It is the calmest part of the cyclone. Before the wind reaches the centre it gets warmed up and rises upward and when the warm air rises and cools off, the moisture forms clouds. This system of clouds and winds continues to grow and spin.
  • This disturbance is fuelled by the ocean’s heat and the water that evaporates from its surface and such storm systems rotate faster and faster.
• Storms that form towards the north of the equator rotate counterclockwise, while those that form to the south spin clockwise because of the rotation of the Earth.
• A hurricane can last for more than 14 days.

Structure:

• Eye– Hurricane winds blow in a counterclockwise spiral around the calm, roughly circular centre called the eye.
  • The eye is the warmest part of the storm and it is relatively calm, clear and there is little or no rain in this region.
• Eyeball- Surrounding the eye is the eyewall, a wall of thunderclouds.
  •  The eyewall has the most rain and the strongest winds of the storm, gusting up to 360 km/h in severe storms.
  • The smaller the eye, the stronger the winds. The winds spiral in a counterclockwise direction into the storm’s low-pressure centre.
• Spiral Rainbands– Long bands of rain clouds appear to spiral inward to the eyewall — these are called spiral rainbands. They contain thunderstorms and sometimes tornadoes

The intensity of Hurricane:

• The Saffir-Simpson Hurricane Wind Scale is a 1 to 5 rating based on a hurricane’s sustained wind speed. This scale estimates potential property damage.
• Category Sustained Winds Types of Damage Due to Hurricane Winds:
  • 119-153 km/h                Some substantial damage
  • 154-177 km/h                 Extensive damage
  • (major) 178-208 km/h             Devastating damage will occur
  •  (major) 209-251 km/h             Catastrophic damage will occur
  •  (major) 252 km/h or high      Catastrophic damage will occur

How they are named?

• Each year, tropical storms are named in alphabetical order. The names come from a list of names for that year. There are six lists of names. Lists are reused every six years.

Source :LS