The correct option is 1 and 3 only.
Explanation
A front is the sloping boundary surface separating two air masses with contrasting physical properties, such as temperature, humidity, and density. The interaction between these air masses leads to distinct weather patterns and is the primary mechanism for the formation of temperate cyclones.
Statement-wise Analysis:
- Statement 1 is Correct: A stationary front occurs when two contrasting air masses meet but neither is strong enough to displace the other. Consequently, the surface position of the front remains static, and winds blow parallel to the frontal boundary.
- Statement 2 is Incorrect: A cold front is formed when a cold air mass moves towards a warm air mass and wedges underneath it due to higher density. The statement describes a warm front, which occurs when an advancing warm air mass slides over a retreating cold air mass.
- Statement 3 is Correct: Fronts are characteristic features of the middle latitudes (30°-65° N/S). In these regions, warm air masses from the tropics converge with cold air masses from the poles, creating the necessary temperature contrast for frontogenesis. Fronts are rare in equatorial regions because the air masses there are generally homogeneous in temperature and humidity.
Key Takeaway:
Fronts are classified based on the movement of air masses: Cold Fronts (cold air advances), Warm Fronts (warm air advances), Stationary Fronts (no movement), and Occluded Fronts (cold front overtakes warm front). They are distinct phenomena of mid-latitude weather systems.