Correct Answer - Option 2 : Radiation fog
Warm currents: Those currents that flow from the Equator towards the poles are warmer than the surrounding water and so they are called warm currents. Examples- Kuroshio current, North Pacific current.
Cold currents: The ocean currents that flow from the polar areas towards the Equator are cooler compared to the surrounding water, so they are called cold currents. Examples- Oya shio current, California current.
Formation of Fog:
When the warm and the cold currents meet, dense fog is created. This is because the air above the warm currents is warm which contains water vapor. When this warm current meets the cold current, the air above the cold current, causes the water vapor of the warm current to condense into tiny particles which form fog. This controls the temperature condition in the fishing regions of the meeting grounds.
There are five types of Fog:
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Radiation fog- They occur in the winter, aided by clear skies and calm conditions. The cooling of land overnight by thermal radiation cools the air close to the surface. This reduces the ability of the air to hold moisture, allowing condensation and fog to occur. Radiation fog usually dissipates soon after sunrise as the ground warms.
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Valley fog- They form where cold dense air settles into the lower parts of a valley, condensing and forming fog. It is often the result of a temperature inversion, with warmer air passing above the valley.
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Advection fog- They occur when moist, warm air passes over a colder surface and is cooled. A common example of this is when a warm front passes over an area with snow cover. It is also common at sea when moist tropical air moves over cooler waters. If the wind blows in the right direction, then sea fog can become transported over coastal land areas.
- Upslope fog- Upslope or hill fog forms when winds blow air up a slope (called orographic uplift). The air cools as it rises, allowing moisture in it to condense.
- Evaporation fog- It is caused by cold air passing over warmer water or moist land. It often causes freezing fog, or sometimes frost. When some of the relatively warm water evaporates into low air layers, it warms the air, causing it to rise and mix with the cooler air that has passed over the surface. The warm, moist air cools as it mixes with the colder air, allowing condensation and fog to occur.
Hence, the correct answer is Radiation fog.
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Rainfall: Rain is droplets of water that fall from clouds. This vapor rise cools and changes into tiny water droplets, which form clouds. The water droplets in the clouds join together to form bigger drops. When the water droplets get too large and heavy, they fall as rain.
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Radiation fog: Radiational cooling produces this type of fog. Under stable nighttime conditions, long-wave radiation is emitted by the ground; this cools the ground, which causes a temperature inversion. In turn, moist air near the ground cools to its dew point. Depending upon the ground moisture content, moisture may evaporate into the air, raising the dew point of this stable layer, accelerating radiation fog formation.
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Cyclone: To form a cyclone, warm, moist air over the ocean rises upward from near the surface. As this air moves up and away from the ocean surface, it leaves and there is less air near the surface. So basically as the warm air rises, it causes an area of lower air pressure below.
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Advection fog: Advection fog forms due to moist air moving over a colder surface, and the resulting cooling of the near-surface air to below its dew-point temperature. Advection fog occurs over both water and land.
