Weather is caused by the rising and falling of warm and cool air called ( ). These currents affect the different air pressures in the atmosphere( ) . Response area occurs when the air cools and begins to sink, while ( ) occurs when the air warms and begins to rise. The differences between these pressures are what causes
( ). Convection can also create ( ) in a small local area.

Answer:Movement of air caused by temperature or pressure differences is wind. Where there are differences of pressure between two places, a pressure gradient exists, across which air moves: from the high pressure region to the low pressure region. This movement of air, however, does not follow the quickest straight line path. In fact, the air moving from high to low pressure follows a spiralling route, outwards from high pressure and inwards towards low pressure. This is due to the rotation of the Earth beneath the moving air, which causes an apparent deflection of the wind to the right in the northern hemisphere, and left in the southern hemisphere. Consequently, air blows anticlockwise around a low pressure centre (depression) and clockwise around a high pressure centre (anticyclone) in the northern hemisphere (see Figure 3.1). This situation is reversed in the southern hemisphere.

Explanation:Movement of air caused by temperature or pressure differences is wind. Where there are differences of pressure between two places, a pressure gradient exists, across which air moves: from the high pressure region to the low pressure region. This movement of air, however, does not follow the quickest straight line path. In fact, the air moving from high to low pressure follows a spiralling route, outwards from high pressure and inwards towards low pressure. This is due to the rotation of the Earth beneath the moving air, which causes an apparent deflection of the wind to the right in the northern hemisphere, and left in the southern hemisphere. Consequently, air blows anticlockwise around a low pressure centre (depression) and clockwise around a high pressure centre (anticyclone) in the northern hemisphere (see Figure 3.1). This situation is reversed in the southern hemisphere.