Roadmap for Answer Writing

Introduction

• Define Jet Streams: Begin by providing a definition of jet streams. Mention that jet streams are narrow, fast-moving air currents found in the upper atmosphere, typically located at altitudes of around 30,000 feet (9,100 meters).
• Formation: Explain how jet streams are formed at the boundary between warm and cold air masses, creating strong winds in the atmosphere.

Types of Jet Streams

• Polar Jet Streams: Located between 50°-60° latitude, generally over polar regions, influencing weather in mid-latitudes.
• Sub-Tropical Jet Streams: Found at around 30° latitude, they are stronger in winter and spring and are associated with fair weather.
• Tropical Easterly Jet Streams: Present over South Asia and Africa, influencing monsoon weather patterns.

Impact of Jet Streams on Weather Patterns

• Weather Boundaries: Discuss how jet streams mark the division between different air masses (cold and warm) and the role they play in developing storm systems (cyclones, thunderstorms).
• Storm Development: Mention the impact of jet streams on the formation of extreme weather events such as severe storms, heavy rainfall, and dry spells.
  • Example: 2014 European Storms – Jet stream meandering contributed to extreme weather conditions in Europe.

Impact on Climate

• Polar Vortex and Cold Air Movement: Explain how a distorted polar jet stream can cause cold Arctic air to move southward, leading to sudden temperature drops in mid-latitude regions.
• Climate Change: Discuss how climate change is affecting the behavior of jet streams, leading to shifts in their position and causing more frequent or prolonged weather events (e.g., droughts, heatwaves, or storms).
  • Example: IPCC Report – The expansion of tropical climate zones due to the poleward shift of jet streams.

Regional Impacts

• India: Explain how the jet streams influence Indian weather, particularly during winter (Western Disturbances) and summer (monsoonal changes).
  • Example: Western Disturbances bring rainfall to northwestern India, affecting agricultural patterns.
  • Example: Monsoon Influence: The shifting of the upper westerly jet stream determines the onset and strength of the monsoon.

Conclusion

• Recap the Role of Jet Streams: Summarize the importance of jet streams in global weather and climate patterns.
• Significance in Climate Change: Emphasize the need to understand how jet streams are changing due to global warming and how this will continue to impact weather patterns and human activities.

Relevant Facts:

1. Definition and Formation:
   • Jet streams are narrow bands of fast-moving air currents in the upper atmosphere.
   • They form at the boundary where warm and cold air masses meet, creating powerful winds.
2. Types of Jet Streams:
   • Polar Jet Streams: Found between 50°-60° latitude, typically influencing mid-latitude weather systems.
   • Sub-Tropical Jet Streams: Located around 30° latitude, strongest during winter, and often associated with fair weather.
   • Tropical Easterly Jet Streams: Found in Southeast Asia and parts of Africa during summer, contributing to monsoon weather patterns.
3. Weather Influence:
   • Jet streams mark the boundaries of different air masses (e.g., warm and cold), and their interaction can lead to storm development.
   • Example: The 2014 European storm season was influenced by a meandering jet stream, causing excessive rainfall and wildfires.
4. Climate Influence:
   • Polar Vortex: A weak or distorted polar jet stream can result in cold Arctic air moving southward, causing freezing temperatures in mid-latitude regions.
   • Impact of Climate Change: The poleward shift of jet streams due to climate change is causing more extreme weather events (e.g., droughts, floods, heatwaves).
5. Impact on India:
   • The Western Disturbances from the westerly jet stream bring winter rains to northwestern India.
   • The Easterly Jet Stream influences the onset and intensity of the Indian monsoon.