We cannot see it. We can hear it. The song of the wind is the most wonderful music on earth, and at times the most terrifying in its angry moments. Air, like water, gets hot and cold. A basic principle of the physics of air is that cold air is heavier than warm air.
Air masses warmed by the sun in the tropics affect the whole earth.
This tropical air, when heated by a burning sun, becomes lighter and is forced upwards by the heavier air in the regions around it. Part of it goes northward carrying heat and water vapor. A great air mass can lie stagnant far to the north of us for days and weeks. It grows colder and colder and finally starts moving south, sounds like shrill trumpets marking its journey. As it travels it reacts to the force caused by the earth rotating on its axis, and then the moving air mass begins to rotate within itself in a clockwise direction.