Types of current. Unlike tidal currents, ocean currents are not dependent on gravitational effect produced by the interaction of sun and moon. They are caused by the differences in level, or in salinity/density, or in temperature between various masses of water, in which case they are called stream currents, or…
Nature. Tropical storms are violent storms with very strong winds and heavy seas. Origin. They occur mostly in the late summer and early autumn (December to April in the southern hemisphere). They originate in the tropics between latitude 5° and latitude 10° north or south and develop only over the…
Life Cycle of a frontal depression. Warm air moves faster than cold and every now and again, it forces its way into the cold air, making a bulge in the polar front. This is the commencement of a frontal depression, since as the warm, less dense air pushes into the…
Air masses are large areas of air which have the same characteristics throughout. They may be warm or cold, depending upon where they originated, ie tropical or polar. They are further classified as either continental or maritime. When two different air masses meet they form a boundary which is known…
Last year we spoke about two atmospheric pressure systems, namely the Depression and the Anti-cyclone. This year we continue with systems which are basically derivatives of the first two: High pressure ridges. They are also known as “wedges”. It is an extension of an anti-cyclone and it could extend in…
The oceanic winds experienced in the various climate zones are described in the following sub paragraphs: Doldrums. The doldrums is that part of the ocean situated in the equatorial trough of low pressure between the trade winds of the two hemispheres. This weather in this zone is characterised by calms,…
