Mains Marathon

Start by giving a brief about the meaning of Arctic warming. Discuss its impact on jet Strems and polar vortex leading to anomalies in weather patterns and extreme events. Conclude accordingly.

Answer:

Arctic amplification, characterized by the accelerated warming of the Arctic compared to the rest of the globe, significantly influences the behavior of jet streams and the polar vortex.

• As per IPCC assessments 2019, the Arctic's average temperature has increased by about 2.0°C since the late 19th century, whereas the global average temperature increase is around 1.0°C.

Arctic Warming Influence on Jet Streams:

• Weakening Jet Streams: As the Arctic warms, the temperature difference between the polar region and lower latitudes decreases. This weaker temperature gradient affects the jet streams, which are fast-flowing, narrow air currents in the upper atmosphere. The weakening of jet streams can lead to them becoming more meandering and moving slower.
• Jet Stream Patterns: Researchers have documented changes in the behavior of jet streams, with increased instances of "blocking" patterns where the jet stream becomes stuck in a certain configuration.
  • In the summer of 2012, a persistent high-pressure system over Greenland blocked the normal path of the jet stream. This resulted in an extended heatwave and drought in the central United States, while other regions experienced heavy rainfall and flooding due to the altered weather patterns.

Arctic Warming Impact on Polar Vortex:

• Vortex Disruption: The polar vortex, a circulation of winds around the Arctic region, can be disrupted by warming-induced changes in atmospheric circulation and temperature gradients.
• Shifts in Vortex Position: Warmer Arctic air can weaken the polar vortex, leading to its southward displacement. This can bring cold air masses farther south than usual, resulting in frigid conditions in lower latitudes.
• Stratospheric Warming: In extreme cases, Arctic warming can influence the stratosphere, causing a phenomenon known as sudden stratospheric warming (SSW), which further disrupts the polar vortex and leads to downstream weather impacts.
• Polar Vortex Displacement: In early 2019, the polar vortex experienced a significant disruption, causing frigid air to move southward into the United States and Canada. Record-breaking cold temperatures were observed, leading to severe winter conditions and transportation disruptions.

Consequences for Weather Patterns and Extreme Events:

• Extreme Temperature Events: The altered behavior of jet streams and the polar vortex can result in prolonged periods of extreme temperatures, such as heatwaves or cold snaps, in regions further from the poles.
  • The unusually cold winter experienced in parts of North America in early 2021, known as the "polar vortex split," led to record-breaking cold temperatures in places that are typically milder.
• Intensified Weather Extremes: Slower-moving jet streams and blocking patterns can amplify weather extremes, leading to longer-lasting and more intense heatwaves, heavy rainfall, or droughts.
  • A study published in the journal "Nature" in 2020 identified a link between Arctic warming and the increased likelihood of severe winter weather events in the Northern Hemisphere.
• Shifts in Storm Tracks: Changes in the jet streams can influence the tracks of storms, altering their paths and intensities, which can have significant implications for regions vulnerable to tropical cyclones or extratropical storms.
• Rapid Ice Melt: The IPCC has reported that Arctic glaciers and ice caps have lost mass at an average rate of around 178 gigatons per year from 2006 to 2015.

As the Arctic warms at an accelerated pace, understanding these complex interactions is crucial for anticipating and mitigating the far-reaching consequences of climate change on our weather systems. The UNDP aims to catalyze global efforts to mitigate Arctic warming's impacts, promote sustainable development, and ensure the well-being of communities and ecosystems that are directly affected by these changes.