The Easterly Waves ,although capable of producing destructive tropical cyclonic damage, used to be a welcome, even life-saving sight to early seafarers who were coming out of the Doldrums. The Doldrums represents an area of ocean on the equator which is canopied by The Inter tropical Convergence Zone existing in the atmosphere directly above the equator. This ‘Doldrums’ area of the ocean is calm, even DEATHLY calm and is paralleled on either side with The Easterly Waves. Early seafarers, depending solely on sails to power their ship, could sit idly in the hot, muggy climate under the Inter tropical Convergence Zone for days or even to their death trying to maneuver through this calm area of ocean. Therefore, the Easterly Waves were a welcome sight indeed.
The Easterly Waves are also called African Easterly Waves, or simply The Tropical Waves. In general they always form from east to west beneath the Subtropical Ridge (area of high pressure in the atmosphere running parallel on the north and south sides of the Inter tropical Convergence Zone. Easterly waves run toward the west direction and are fueled by the easterly winds in the Subtropical Ridge.
The forming of tropical cyclones is their most notorious claim to fame. Although one would think it’s a terrible claim to fame, cyclones in fact are very important natural phenomenon that play a vital role in helping to regulate the earth’s temperature in the troposphere. They remove some heat and energy from the tropics and bring it to more equable latitudes. ‘Tropo’ is from the Greek term meaning ‘turning’ or ‘mixing’ which is exactly what the earth’s troposphere does. It is the first 7 to 20 km of atmosphere that extends out from the earth’s surface. It is only 7km around the poles and it is deepest above the tropics. It is responsible for most weather that affects our lives. In this way, the Troposphere which depends on the assistance of Tropical Cyclones to regulate the earth’s temperature, benefits from Easterly Waves. Even though we may never have seen them or even heard of them before, our privilege of living in a balanced, life-sustaining climate is due in part to Easterly Waves.
