The weather is just the state of the atmosphere at any time, including things such as temperature, precipitation, air pressure and cloud cover. Daily changes in the weather are due to winds and storms. Seasonal changes are due to the Earth revolving around the sun.
What is weather?
What causes weather?
Because the Earth is round and not flat, the Sun's rays don't fall evenly on the land and oceans. The Sun shines more directly near the equator bringing these areas more warmth. However, the Polar Regions are at such an angle to the Sun that they get little or no sunlight during the winter, causing colder temperatures. These differences in temperature create a restless movement of air and water in great swirling currents to distribute heat energy from the Sun across the planet. When air in one region is warmer than the surrounding air, it becomes less dense and begins to rise, drawing more air in underneath. Elsewhere, cooler denser air sinks, pushing air outward to flow along the surface and complete the cycle.
How do meteorologists forecast the weather?
Weather forecasting is a prediction of what the weather will be like in an hour, tomorrow, or next week. Weather forecasting involves a combination of computer models, observations, and knowledge of trends and patterns. By using these methods, reasonable accurate forecasts can be made up to seven days in advance.
What is wind?
Wind is air in motion. It is produced by the uneven heating of the earth’s surface by the sun. Since the earth’s surface is made of various land and water formations, it absorbs the sun’s radiation unevenly. Two factors are necessary to specify wind: speed and direction.
What causes the wind to blow?
As the sun warms the Earth's surface, the atmosphere warms too. Some parts of the Earth receive direct rays from the sun all year and are always warm. Other places receive indirect rays, so the climate is colder. Warm air, which weighs less than cold air, rises. Then cool air moves in and replaces the rising warm air. This movement of air is what makes the wind blow.
Experiments:
- Tornado in the bottle
- Fire Tornado
- Weather Balloon
Weather Instruments: wind direction and speed
Weather stations are located all across the country, each contributing to a large network of data to giving a snapshot of localised weather, as well as helping to build an holistic view of the UK’s climate. A weather station is a facility, either on land or sea, with instruments and equipment for measuring atmospheric conditions to provide information for weather forecasts and to study the weather and climate. The measurements taken include temperature, atmospheric pressure, humidity, wind speed, wind direction, and precipitation amounts.
Typical weather stations have the following instruments:
- Thermometer for measuring air and sea surface temperature
- Barometer for measuring atmospheric pressure
- Hygrometer for measuring humidity
- Anemometer for measuring wind speed
- Pyranometer for measuring solar radiation
- Rain gauge for measuring liquid precipitation over a set period of time.
- Wind sock for measuring general wind speed and wind direction
- Wind vane, also called a weather vane or a weathercock: it shows whence the wind is blowing.