Clouds

A cloud is a large collection of very tiny droplets of water that are so small that they can float in the air. Clouds exist in a variety of types. Each type of cloud forms under certain circumstances of temperature, pressure, and humidity. All air contains water, but near the ground it is usually in the form of an invisible gas called water vapor. When warm air rises, it expands and cools. Cool air can't hold as much water vapor as warm air, so some of the vapor condenses onto tiny pieces of dust that are floating in the air and forms a tiny droplet around each dust particle. When billions of these droplets come together they become a visible cloud. There are three different groups of clouds: Cirrus, Alto, and stratus clouds. To learn more about clouds, click here!

Different Instruments Used to Measure Weather

A raingage is an instrument used my meteorologists and hydrogolists. It measures the amount of liquid precipitation over time. These gauges work by catching the falling rain in a funnel-shaped collector that is attached to a measuring tube. It measures in inches.

The picture above I got from google images.

If you want to learn more about the raingage click here!

A hygrometer is another device scientists use. A hygrometer is used to measure relative humidity, which is a measure of how much water the air is holding. A hygrometer measure in percent, with 100% being the highest measure. Wet and dry bulb psychrometers are the most simple and common way of measuring humidity. This type of hygrometer uses two basic mercury thermometers, one with a wet bulb one with a dry bulb. Evaporation from the water on the wet bulb causes its temperature reading to drop, causing it to show a lower temperature than the dry bulb. A physcrometer is pretty common to the hygrometer.

The picture above I got from about.com

If you want to learn more about the hygrometer click here!

An anemometer is another instrument meteoroligists use to measure weather. The anemometer is used to measure wind speed. This device has four small hollow cones set on a metal rod so that they can catch the wind and revolve around the pole. Then, a electronic device records the amount of revolutions, then calculates wind speed. The wind speed is measure in miles per hour.

The image of the anemometer i found at about.com

If you want to learn more about the anemometer click here!

A barometer is another widely used weather instrument that measures air pressure, which is the weight of the air in the atmosphere. There are two main types of barometers the most widely available and reliable Mercury Barometers, or the newer edition, the Aneroid Barometer. The original barometer is a glass tube about 3 feet high with one end open and the other end closed. The tube is filled with mercury. This glass tube sits upside down in a container, called the reservoir, which also contains mercury.In areas of low pressure, air is rising away from the surface of the earth more quickly than it can be exchanged by air flowing in from surrounding areas. This decreases the weight of air above the reservoir so the mercury level drops to a lower level. This is measure in millibars.

The image of the barometer i found at about.com

If you want to learn more about the barometer click here!

A thermometer is one instrument that measures the temperature of things. The name is made up of two smaller words.Thermo, which means heat and,meter, which means to measure. You can use a thermometer to tell the temperature of anything. The red color part of the thermometer moves up and down depending on the temperature. The red part in this glass tube is usually either alchohol or a substance called mercury. Both grow bigger when they're hot, and smaller when they're cold, which causes the red part to move up and down. The thermometer measures temperatures in Fahrenheit, Celsius and another scale called Kelvin. Fahrenheit is pretty much used all time in the United States, and most of the rest of the world uses Celsius. Kelvin is rarely used, mostly just scientists use it.

About Weather

The term weather describes the state of air at a particular place and time. Weather is the atmosphere we're living in right at this very moment. Weather describes how hot or cold it is outside, wet or dry, and how cloudy or windy it is. Scientists that study weather, meteorologists, use many different instruments to measure the different aspects of weather.

To learn more about weather click here!