Polar easterlies

Definition

Polar easterlies are cold winds that blow from the east near the polar regions, specifically the Arctic and Antarctic. These winds are a result of high-pressure systems at the poles, which lead to the sinking of cold air and create a consistent flow towards lower latitudes, contributing to the general circulation of the atmosphere and influencing weather patterns in both polar and temperate regions.

5 Must Know Facts For Your Next Test

1. The polar easterlies typically occur between 60 degrees latitude and the poles, where cold air sinks and creates high-pressure systems.
2. These winds are generally weak but can significantly affect local weather conditions, especially in coastal areas of the polar regions.
3. As the polar easterlies move towards lower latitudes, they can interact with warmer air masses, leading to the formation of storm systems.
4. In the Southern Hemisphere, polar easterlies contribute to the formation of the Antarctic Circumpolar Current, influencing ocean circulation.
5. The strength and direction of polar easterlies can vary seasonally, with stronger winds often observed during winter months.

Review Questions

• How do polar easterlies contribute to the overall circulation patterns in the atmosphere?
  • Polar easterlies play a crucial role in atmospheric circulation by helping to redistribute cold air from the poles toward lower latitudes. As cold air sinks at the poles, it creates high-pressure areas that drive these winds. When these winds meet warmer air masses from lower latitudes, they can lead to various weather phenomena, including storms. This interaction contributes to the larger patterns of circulation within both the Hadley and Ferrel cells.
• Discuss the impact of polar easterlies on weather systems in mid-latitude regions.
  • Polar easterlies can significantly influence weather systems in mid-latitude regions by interacting with prevailing westerlies. When cold polar air moves southward, it can collide with warmer air from the tropics, resulting in temperature contrasts that lead to storm development. These interactions are essential for understanding mid-latitude cyclones and can alter precipitation patterns as well as temperature fluctuations throughout different seasons.
• Evaluate how changes in climate could affect the behavior of polar easterlies and their implications for global weather patterns.
  • Climate change may alter the behavior of polar easterlies by impacting temperature gradients between the poles and equator. As polar regions warm more rapidly than other areas, this could weaken or shift these wind patterns, leading to unpredictable weather events. For instance, a potential weakening of polar easterlies might cause shifts in storm tracks in mid-latitudes, possibly increasing extreme weather events like heavy rainfall or prolonged droughts. Understanding these changes is vital for predicting future climate impacts on global weather systems.

Related terms

Trade Winds: These are steady winds that blow from east to west between the equator and 30 degrees latitude, driven by the Earth's rotation and solar heating.

Jet Stream: A fast-flowing ribbon of air high in the atmosphere that can influence weather patterns and is affected by temperature differences between polar and tropical regions.

Coriolis Effect: The apparent deflection of moving objects caused by the rotation of the Earth, which affects wind direction and helps to establish global wind patterns.