1. How do ocean currents affect global climate? Illustrate by taking suitable examples.
महासागर धाराएं वैश्विक जलवायु को कैसे प्रभावित करती हैं? उपयुक्त उदाहरण लेकर दर्शाएं।
Ocean currents are body of water mass with a slightly different thermophysical characteristic viz temperature, density and salinity from the surrounding water body. They move in a well-defined path like a river in the ocean and is influenced by the direction of wind and the coastal features.
Effects of Currents on Climate:
- Temperature and Humidity: Warm current increases the temperature and humidity of the coastal area through which it passes, such as the Norwegian current which increase the temperature of the coastal areas of North Sea make the port workable and climate cool and moist.
- Coastal climates: Most of warm current are found in eastern margin of continent in lower latitude and influencing the coastal climate such as North Atlantic drift in eastern USA, Florida current in gulf of Florida etc.
- Desiccating effects: Cold current brings the temperature down and creates a desiccating effect and foggy condition in the coastal area through which it passes.
- Desert: Most of the cold current are found in the western margin of the continents in lower latitude which is associated with the desert landforms in these latitudes eg California current in western USA, Peru current in western south America etc.
- Fog: Places where cold currents meet warm currents are characterized by Fog conditions which make navigation difficult. These areas are also characterized by fishing grounds due to abundance of nutrients to support marine life.
- Global thermohaline circulation: Ocean currents act as global conveyor belts which transfer heat from one part of the earth to another. They regulate the coastal climate thereby indirectly regulating the vegetation, fauna and the lifestyles of the people.
- Fishing grounds: In E. Asia meeting of the warm Kuroshio and the cold Oyashio current provides ideal conditions for rich fishing grounds in Japan. However, navigation becomes difficult due to thick fog.
- El-Nino and La-Nino: El-Nino is also caused due to periodic changes in cold water current replace by warm water currents off Peruvian coasts which affects monsoon in south Asia.
Note: While giving examples for physical geography questions try give diverse examples. Like for this question, u can include examples each from Asia, America, Africa, Europe continents to score high marks.
Best answer: Neha Kumari