How do we describe the atmosphere? We use temperature, pressure, wind, humidity and precipitation. All these are elements of weather and climate.
So here we learn about humidity and precipitation and what are all the differences are between these two.
What is Humidity?
How does the water cycle work in the atmosphere? How the hydrosphere and atmosphere interact with each other.
Water vapour is a very important component of the atmosphere. In most places, the amount of water vapour in the atmosphere varies over time and as part of changing weather patterns. In many places, in winter, it is dry and cold. In such places, our skin may feel itchy, dry, and it may crack. You will probably have experienced cracked lips for which you may have used lip balm, oil or vaseline etc; of some kind.
Combined with high temperature, it is water vapour that causes you to feel sultry and sweaty. When this happens we say it is ‘very humid’ or ‘the humidity is high’. But not all places are similar in this respect. Some places feel very dry (examples: deserts). The moisture (water vapour) in the atmosphere is derived from water bodies through evaporation and from plants through evaporation and plants through transpiration. Humidity is the amount of water vapour in the air. In high humidity, our sweat doesn’t cool us because it cannot evaporate. In humidity, we also feel more thirsty.
We express humidity not directly but using the concept of relative humidity. The relative humidity is the ratio between two things:
- The maximum water vapour that the air can hold at a given temperature and pressure, and of water vapour it holds at any given time.
- The actual amount of water vapour it holds at any given time.
What is Precipitation?
Condensation is the opposite of evaporation, as it involves the conversion of water vapour into droplets of water or crystal of ice. With condensation, the droplets get heavy and fall to earth as precipitation (from the Latin precipitation meaning to fall headlong, to plummet) – in the form of rain, snow, hail etc; if these droplets condense very close to earth’s surface, the droplets are lighter and we get fog.
Rainfall is the most common form of precipitation. When condensation takes place at a temperature below freezing point, water vapour condenses directly into ice crystals. These may fall down on the earth as powdery masses or flakes of snow. This form of precipitation is called snowfall. Snowfall is quite common in middle and high latitudes and mountain regions.
When rain falls through a cold layer of air near the earth’s surface, raindrops get frozen into ice and fall down. This form of precipitation is called sleet.
When there are strong vertical currents in the atmosphere, condensation takes place at high altitudes at low temperatures. Ice crystals grow in size gradually but do not fall down owing to ascending currents. Eventually, the ice crystals grow to a large size of a few centimetres in diameter and fall down as solid masses. This form of precipitation is called a hailstone. Hailstone causes damage to crops and buildings.
Let’s summarize the difference between Humidity and Precipitation
Difference between Humidity and Precipitation:
|Humidity is the amount of water vapor in the air.||Precipitation is falling out of the sky to the earth.|
|When humidity is high it means there is a lot of water vapor in the air. The air feels sticky and we sweat a lot||Sometimes clouds form near the surface of the earth. Such clouds are known as fog.|
|When humidity is low it means there is hardly any water vapor in the air. The air feels dry and our skin and lips start cracking||Snowfall takes place when water vapor cools so quickly that it turns directly into solid.|
|Humidity is measured using a dry and wet bulb hygrometer.||Rain is the most common form of precipitation. It is measured in millimeters using a rain gauge|
So, when we compare the terms humidity and precipitation it clarifies that humidity and precipitation are two different aspects that occur in atmospheres of different altitudes and regions.
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