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Examine the formation of mid-latitude depressions and anticyclones, and the weather patterns associated with them. - Leaving Cert Geography - Question 24 - 2015
Question 24
Examine the formation of mid-latitude depressions and anticyclones, and the weather patterns associated with them.
Worked Solution & Example Answer:Examine the formation of mid-latitude depressions and anticyclones, and the weather patterns associated with them. - Leaving Cert Geography - Question 24 - 2015
Step 1
Examine the formation of mid-latitude depressions
Answer
Mid-latitude depressions, often referred to as extratropical cyclones, form due to the convergence of cold and warm air masses. This typically occurs along the polar front, where cold polar air meets warm tropical air. The lifting of the warm air results in a low-pressure system, characterized by rising air and the development of clouds and precipitation.
These depressions are associated with the following features:
- Frontal Boundaries: Cold fronts and warm fronts delineate the contrasting air masses. The cold front moves faster than the warm front, leading to significant weather changes as the depression intensifies.
- Occluded Fronts: Eventually, the cold front catches up with the warm front, leading to the occlusion phase where the warm air is lifted away from the surface.
As the depression matures, it can lead to severe weather events, including heavy rainfall, thunderstorms, and high winds.
Step 2
Examine the formation of anticyclones
Answer
Anticyclones, or high-pressure systems, typically form in stable air masses where air descends. This descent creates higher pressure at the surface and inhibits cloud formation, resulting in clear skies and calm weather.
The characteristics of anticyclones include:
- Subsidence: The descending air warms adiabatically, which reduces humidity and leads to dry conditions.
- Stability: This stability often results in prolonged periods of fair weather.
Anticyclones can influence regional weather patterns by blocking the progression of depressions, leading to drought conditions over extended periods.
Step 3
Discuss the weather patterns associated with mid-latitude depressions and anticyclones
Answer
The weather patterns associated with mid-latitude depressions are typically dynamic and vary significantly with the season. These include:
- Increased Precipitation: As warm air rises and cools, it condenses to form clouds and precipitation.
- Stormy Conditions: Frequent changes in weather, including high winds and rapidly shifting temperatures.
In contrast, weather patterns associated with anticyclones typically include:
- Clear Skies: Due to subsidence, areas under the influence of an anticyclone experience little cloud cover.
- Stable Weather: Generally calm and settled weather, with temperatures varying more slowly.
In summary, while mid-latitude depressions are synonymous with active, stormy weather, anticyclones provide a counterbalance of stability and calm.