Environment Current Affairs - 2019
Latest Environment Current Affairs 2019 for UPSC Exams, Bank Exams, Civil Services, SSC and other Competitive Exams. Latest developments in Environment and Climate Change 2019 all important national updates in Environment events for the year 2019.
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The bomb cyclone swept has through the US Great Plains resulting in blizzard conditions, hurricane-like winds, snow and heavy rain and subsequent flooding.
Bomb Cyclone or Bombogenesis
Bomb Cyclone or bombogenesis refer to a rapidly intensifying area of low-pressure winter storm when there is a pressure drop by at least 24 millibars in 24 hours. The decrease of the pressure intensifies the storm. This pressure drop intensification and subsequent winter storms result in strong winds, beach erosion and coastal flooding, especially with high tide.
Bombogenesis storm can be tropical or non-tropical and proximity to a large body of water, particularly an ocean, during cold months contributes to the creation of a bomb cyclone.
Bomb Cyclone is caused by a collision of warm air and cold air which develop into rotating storm-like pattern and lead to an explosive deepening of pressure. Worldwide about 40 to 50 ‘bomb cyclones brew each year.
Tropical Cyclone Idai has caused huge deaths and economic losses in Mozambique, Malawi, Zimbabwe, and South Africa. Cyclone Idai made landfall on Mozambique and later moved in a westerly direction. Idai is the deadliest Tropical cyclone witnessed in 2019.
Idai originated from a tropical depression that formed off the eastern coast of Mozambique and made landfall in Mozambique. The depression later reemerged into the Mozambique Channel and was upgraded into Moderate Tropical Storm.
Tropical Cyclone is an intense low-pressure area or a whirl in the atmosphere over tropical or sub-tropical waters, with organised convection, circulating either anti-clockwise (in the northern hemisphere) or clockwise (in the southern hemisphere).
Conditions which favour Tropical Cyclone Formation
- A source of warm, moist air derived from tropical oceans with sea surface temperature normally near to or in excess of 27 °C
- Winds near the ocean surface blowing from different directions converging and causing air to rise and storm clouds to form
- Winds which do not vary greatly with height known as low wind shear. This allows the storm clouds to rise vertically to high levels.
- Coriolis force/spin induced by the rotation of the Earth. The formation mechanisms vary across the world, but once a cluster of storm clouds starts to rotate, it becomes a tropical depression. If it continues to develop it becomes a tropical storm, and later a cyclone/ super cyclone.
Pressure increases outwards from the centre of a cyclonic storm. The amount of the pressure drop in the centre and the rate at which it increases outwards gives the intensity of the cyclones and the strength of winds.