Introduction / Context:
Earth’s general circulation produces three major wind belts per hemisphere: Trade Winds (tropics), Westerlies (mid-latitudes), and Polar Easterlies (high latitudes). Identifying their latitudinal extent is a common climatology objective.
Given Data / Assumptions:
- Polar Easterlies blow from the polar highs toward subpolar lows.
- They are cold, dry surface winds.
- We match them to a latitude band, not a single line.
Concept / Approach:
The Polar Easterlies generally occupy the high-latitude zone from about 60° to 90° in each hemisphere. In contrast, the Trades are 0–30°, and the Westerlies dominate 30–60°. Therefore, the correct selection is the 60–90° band, representing the polar regions where easterly surface flow is prevalent.
Step-by-Step Solution:
Recall three-cell model: Hadley (0–30°), Ferrel (30–60°), Polar (60–90°).Associate wind belts: Trades (0–30°), Westerlies (30–60°), Polar Easterlies (60–90°).Select “60–90° latitude.”
Verification / Alternative check:
Standard climate diagrams place the polar easterly arrows in the 60–90° area, confirming the choice.
Why Other Options Are Wrong:
0–30°: Trade wind zone.30–60°: Westerlies dominate.90° latitude: A line, not a belt; winds vary around the pole.
Common Pitfalls:
Memorizing the bands without conceptualizing the three-cell circulation; understanding cells helps prevent mix-ups.
Final Answer:
60–90° latitude
Discussion & Comments