Pressure changes effects everything living on this planet including the way we feel, it shapes our personality without us knowing it. When pressure is high the subsiding air which is to be found beneath anticyclones can reduce the sea level by about 3 metres. When the pressure is low, the air is rising and pressure reduced so sea levels can rise by the same amount. Hence, when we experience low pressure with a rise of sea level, coupled with a strong sea surge due to strong winds and a high tide, coastal flooding becomes high risk. This almost occurred along the East coast of England earlier this year. Like every substance, air has its own weight. The atmosphere is over 600 km (370 miles) thick, and the weight of the air forces down on the Earth's surface. The downward force exerted by the weight of the air is called pressure. Air molecules are squeezed together by the weight of air above, making the air denser near the bottom of the atmosphere than it is at higher altitudes. Air density and pressure are greatest at sea level and decrease the higher one goes. Heat also makes air less dense, so less heavy, by moving its molecules. The warmer the air, the lower the air pressure.

Next Week.....The Atmosphere.The answer to last week's question: 5,700 degrees c.This week's question: The atmosphere is over:A/ 900 km thick.B/ 600 km thick.Good Luck. Glossary: Atoms:/b> The smallest parts of an element-such as hydrogen or oxygen.

Weather for coming week Monday 18th February - Friday 22nd February

The blocking anticyclone will decline but will still be close to the southern part of the UK, whilst low pressure systems tracks to the north bringing most of any wind and rain to those northern parts.

Monday and Tuesday both fine days once early morning-tide mist, fog and frost melts away. Sunshine and light east to south-east airflow.

Wednesday-Friday turning slowly milder from off the Atlantic, still with plenty of dry weather, any rain or showers not amounting to much with some spots staying dry. Moderate to fresh south-west winds.

Maximum day temperature 10-13c 50-55f.

Minimum night temperature Zero to Minus 5c early in week then 8-10c 46-50f.

Last Week's Observations (Monday-Sunday)

Highest day temperature...........14.1c 57f on Tuesday 12th February.

Lowest night temperature.........minus 7.6c 18f on Saturday 16th February.

Wettest day............................No rainfall logged.