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17th November 2022 (7 Topics)

The new weather system in the Bay of Bengal likely to impact the north coastal belt

Context

IMD forecasts the formation of a low-pressure area over the southeast Bay of Bengal, thereby increasing the rainfall in the coastal districts of Tamil Nadu.

Details

Details:

  • The formation of a low-pressure area over the Southeast Bay of Bengal and the adjoining Andaman Sea is expected to intensify into a depression over central parts of the South Bay of Bengal.
  • Prevailing upper air circulation would influence the formation of the fresh system.
  • Weather models have indicated rain in the coastal parts of Tamil Nadu.

What is the pressure system?

  • A pressure system is an area of the Earth’s atmosphere that has a particularly high or low pressure compared to the surrounding
  • Types of pressure systems are:
    • Low-Pressure System
    • High-Pressure System

What is a low-pressure system?

  • A low-pressure area is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence that occur in upper levels of the troposphere.
  • A low-pressure system is formed due to localized heating caused by greater sunshine over deserts and other landmasses.
    • Since the warm air in localized areas is less dense than the surroundings, the warm air rises, lowering the atmospheric pressure.
    • Large-scale thermal lows over continents help create pressure gradients that drive monsoon circulations.
    • Due to Earth’s spin and the Coriolis effect, winds of a low-pressure system swirl counterclockwise. This type of flow is known as cyclonic flow.
  • Around the world, the low-pressure systems are most frequently located over the Tibetan Plateau and the lee of the Rocky Mountains. In Europe, the recurring low-pressure weather system is known as depressions.

High-Pressure System

  • High-pressure systems are normally associated with light winds at the surface and subsidence at the lower portion of the troposphere.
  • Subsidence dries out an air mass by adiabatic or compressional heating. Hence, high pressure usually results in clear skies.
  • Since no clouds are present to obstruct the incoming shortwave solar radiation, the temperature rises during the day.
  • At night, due to the absence of clouds, the outgoing longwave radiation is not absorbed and results in cooler low temperatures in all seasons
  • A high-pressure system swirls in the opposite direction from a low-pressure system. This type of flow is known as anticyclonic flow.
  • In high mountainous areas, rice takes more time to cook because low pressure reduces the boiling point of water.

The seven pressure belts are:

1. Equatorial Low-Pressure Belts

2. Subtropical High-Pressure Belts (two)

3. Circum-Polar Low-Pressure Belts (two)

4. Polar High-Pressure Areas (two)

Vertical Variation of Pressure

  • In the lower atmosphere, the pressure decreases rapidly with height.
  • In general, the atmospheric pressure decreases on average at the rate of about 34 millibars every 300 meters of height.
  • The vertical pressure gradient force is much larger than that of the horizontal pressure gradient. But it is generally balanced by a nearly equal but opposite gravitational force. Hence, we do not experience strong upward winds.
  • Due to gravity, the air at the surface is denser and hence has higher pressure. Since air pressure is proportional to density as well as temperature, it follows that a change in either temperature or density will cause a corresponding change in pressure.
  • The pressure decreases with height. At any elevation, it varies from place to place and its variation is the primary cause of air motion, i.e., wind which moves from high-pressure areas to low-pressure areas.
  • A rising pressure indicates fine, settled weather, while a falling pressure indicates unstable and cloudy weather.

Horizontal Distribution of Pressure

An isobar is a line connecting points that have equal values of pressure. Isobars are analogous to the contour lines on a relief map.

  • The distribution of atmospheric pressure over the globe is known as the horizontal distribution of pressure.
  • It is shown on maps with the help of
  • The spacing of isobars expresses the rate and direction of change in air pressure.
  • This change in air pressure is referred to as the pressure gradient.
    • The pressure gradient is the ratio between the pressure difference and the actual horizontal distance between two points.
  • Close spacing of isobars expresses a steep pressure gradient while wide spacing indicates a gentle pressure gradient.
  • The horizontal distribution of atmospheric pressure is not uniform in the world. It varies from time to time at a given place; it varies from place to place over short distances.
  • The factors responsible for variation in the horizontal distribution of pressure are as follows:
  1. Air temperature
  2. The earth’s rotation
  3. Presence of water vapor

SHORT NEWS

Economy

IFSCA signs MoU with RBI in the field of regulation, supervision of regulated entities

  • MoU: To collaborate in the field of regulation and supervision of regulated entities in their respective jurisdictions.
  • The RBI is the central bank and monetary authority of India carrying on, inter-alia,
    • the regulation and supervision of banks and non-banking financial institutions
    • undertaking other functions and exercising powers in accordance with various statutes
  • IFSCA is a statutory authority established under the IFSCA Act 2019.
  • It is headquartered at GIFT City, Gandhinagar in Gujarat.
  • The IFSCA is a unified authority for the development and regulation of financial products, financial services, and financial institutions in the International Financial Services Centre (IFSC) in India.
  • The GIFT IFSC is currently the maiden international financial services center in India.

Environment

India Ranks 8th in Climate Change Performance Index

  • Climbing two spots on the Climate Change Performance Index (CCPI) 2023, India has bagged the eighth position out of the 63 countries that were assessed.
  • The CCPI evaluates 59 countries and the European Union that contribute to the generation of greenhouse gas (GHG) emissions.
  • Rankings for the CCPI are decided as per a standardized criterion, with 14 indicators across four primary categories:
    • Renewable Energy
    • Greenhouse Gas Emissions
    • Climate Policy
    • Energy Use
  • The ranking is done by Germanwatch, NewClimate Institute, and the Climate Action Network.

Environment

2022 Summit of the Leadership Group for Industry Transition (LeadIT)

 

  • India and Sweden hosted the LeadIT Summit on the sidelines of COP27.
  • The Lead IT (Leadership for Industry Transition) initiative focuses on the low carbon transition of the hard-to-abate industrial sector. 
  • LeadIT gathers countries and companies that are committed to action to achieve the Paris Agreement.
  • It was launched by the governments of Sweden and India at the UN Climate Action Summit in September 2019.
  • It is supported by the World Economic Forum.
  • LeadIT members subscribe to the notion that energy-intensive industries can and must progress on low-carbon pathways, aiming to achieve net-zero carbon emissions.
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