Aula EcoPlanet: WEATHER AND CLIMATE.

What is climate?

Climate is the average weather usually taken over a 30-year time period for a particular region and time period. Climate is not the same as weather, but rather, it is the average pattern of weather for a particular region. Weather describes the short-term state of the atmosphere.

Climate is a country’s normal weather over a long period of time. By climate we mean a country’s rain and sunshine, winds, storms and everything else that makes up the weather.

The weather changes from day to day and even from hour to hour. It can be sunny in the morning and cold and wet in the afternoon. The climate changes very slowly over thousands of years.

We know that the Equator means heat and the Arctic means cold. Climates are also affected by how close a country is to the sea and by how high a country is.

What is weather?
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.

There is one basic reason we have weather, and that is the sun. Weather systems start because the sun’s energy heats up some parts of Earth more than others. Most of the time the sun shines most directly on the middle of Earth, with less heating at the north and south poles. Earth is tilted on its axis at exactly the right angle to have seasons, with different parts of Earth being heated more or less during different times of the year. Land heats up faster than water, wetting up temperature differences between oceans and continents. This unequal heating creates variations in temperature and air pressure, winds, and ocean currents.

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.

SEASONS.

We divide up the year into four seasons: spring, summer, autumn, and winter. Each season lasts 3 months with summer being the warmest season, winter being the coldest, and spring and autumn lying in between.

The seasons have a lot of impact on what happens on the earth. In the spring, animals are born and plants come back to life. Summer is hot and is when kids are usually out of school and we take vacations to the beach. Often crops are harvested at the end of the summer. In autumn the leaves change colors and fall off the trees and school starts again. Winter is cold and it snows in many places. Some animals, like bears, hibernate in the winter while other animals, like birds, migrate to warmer climates.

Seasons are caused because of the Earth's changing relationship to the Sun. The Earth travels around the Sun, called an orbit, once a year or every 365 days. As the Earth orbits the Sun the amount of sunlight each place on the planet gets every day changes slightly. This change causes the seasons.