In the neighbourhood of the Aleutian Islands in the Pacific Ocean and...
Sub-Polar low pressure belt
Key Points:
- The Aleutian Islands in the Pacific Ocean and the region between Greenland and Iceland in the Atlantic Ocean are known for the presence of low-pressure centers.
- These low-pressure centers are a result of the Sub-Polar low-pressure belt.
Explanation:
The Earth's atmospheric circulation is driven by the temperature differences between the equator and the poles. This circulation forms a series of pressure belts around the globe. One such pressure belt is the Sub-Polar low-pressure belt.
The Sub-Polar low-pressure belt is located between the Sub-Tropical high-pressure belt and the Polar high-pressure belt. This belt is characterized by unstable weather conditions and frequent storms. It is also known for its strong winds and heavy precipitation.
The Aleutian Islands, which are part of the Alaska Maritime National Wildlife Refuge, are located in the Pacific Ocean. The region between Greenland and Iceland, known as the Denmark Strait, is located in the Atlantic Ocean. Both of these regions fall within the Sub-Polar low-pressure belt.
In the Sub-Polar low-pressure belt, warm air from the Sub-Tropical high-pressure belt and cold air from the Polar high-pressure belt converge. The warm air rises, creating a low-pressure area. This low-pressure area results in the formation of storm systems and cyclones.
The convergence of warm and cold air masses also leads to the development of strong winds and atmospheric instability. These conditions contribute to the frequent occurrence of storms and heavy precipitation in the vicinity of the Aleutian Islands and between Greenland and Iceland.
In conclusion, the low-pressure centers found in the neighbourhood of the Aleutian Islands in the Pacific Ocean and between Greenland and Iceland in the Atlantic Ocean are a result of the Sub-Polar low-pressure belt. This belt is characterized by unstable weather conditions, frequent storms, strong winds, and heavy precipitation.
In the neighbourhood of the Aleutian Islands in the Pacific Ocean and...
- Sub-Polar low-pressure belt is located between 60-65 degree latitudes in both the hemispheres. The low-pressure belt does not appear to be thermally induced because there is low temperature throughout the year. The surface air spreads outward from this zone due to the rotation of the earth and low pressure is caused. Instead of a regular and continuous belt, there are well-defined low-pressure centres or cells over the oceans in the northern hemisphere e.g. in the neighbourhood of the Aleutian Islands in the Pacific Ocean and between Greenland and Iceland in the Atlantic Ocean. Hence option (c) is the correct answer.
- The sub-tropical highs extend from near the tropics to about 35°N and S. After saturation (complete loss of moisture) at the Intertropical Convergence Zone (ITCZ), the air moving away from equatorial low pressure belt in the upper troposphere becomes dry and cold. This dry and cold wind subsides at 30°N and S. So the high pressure along this belt is due to subsidence of air coming from the equatorial region which descends after becoming heavy.
- Equatorial Low Pressure Belt lies between 10°N and 10°S latitudes. This belt is the zone of convergence of trade winds from two hemispheres from sub-tropical high pressure belts. As this region lies along the equator, it receives highest amount of insolation. Due to intense heating, air gets warmed up and rises over the equatorial region (convection).Whenever there is vertically upward movement of air, the region at the surface will be at low pressure. Thus the belt along the equator is called equatorial low pressure belt.
- The polar highs are small in area and extend around the poles. They lie around poles between 80 – 90° N and S latitudes. The air from sub-polar low pressure belts after saturation becomes dry. This dry air becomes cold while moving towards poles through upper troposphere. The cold air (heavy) on reaching poles subsides creating a high pressure belt at the surface of earth.
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