British Sign Language Glossaries of Curriculum Terms

BSL Environmental Science Glossary - Atmospheric Pressure System definition

Description: Air in the atmosphere has weight. Whilst this is difficult to imagine, we can think about it in the same way as we think about water. As we go deeper, the volume of water above increases along with the pressure and the same is true of the air in the atmosphere. Whilst we can't see it, atmospheric pressure is always present. Air can also move in various ways, and this creates different pressure systems. In a low-pressure system, the air is rising and as it does so cloud form, which then results in rain, storms and wind. In a high-pressure system, air is descending; when this happens, clouds disperse and the weather is clearer, calmer and drier.