Monsoon zones exist all around the world, for example Chile, North America, Africa and Australia, and not just in India and south-east Asia where we are most familiar with them. The main characteristic is that there are two seasons, wet and dry, caused by winds which blow in opposite directions. South-east Asia experiences north-east monsoons in winter and south-east monsoons in summer.
In the dry season, a stable mass of air rests over a monsoon region, and dry winds come from the interior of the land bringing fine weather. In the wet season, when temperatures rise over the land, the air there becomes warmer than that over the sea. As this warm air rises, cooler air from the sea moves in to replace it bringing with it the very moist air that causes the exceptionally high rainfall associated with monsoons. In the northern hemisphere, the rainy season usually starts around May and works on through the summer with heavy rain in June, July and August. In the monsoon zones of the southern hemisphere, like that of north and north-eastern Australia, the wettest months are January and February.
Monsoons vary according to the part of the world in which they occur, with the monsoon in the eastern Soviet Union accompanied by cold, freezing weather in winter.
In some monsoon regions, such as those in China, Japan and eastern Australia there can be rainfall all year round, although most of it will still fall in the wet, summer season.
However, in the more 'classic' monsoons of India up to three-quarters of the annual rainfall may fall in just three summer months. The agricultural culture of countries like this is based on the expected arrival of the monsoon rains to water crops. Unfortunately, as we have seen from the news in recent years, the monsoons can also bring with them appalling flooding and loss of life. On the other hand, there have been times when the monsoon rains have 'failed', bringing about a tragic chain reaction of ruined harvest and widespread famine.
The Taiga Climate Zone
The climate of the Taiga, named after a Russian word, is a phenomenon of the northern hemisphere. The Taiga stretches below the Arctic regions of the Soviet Union and North America, and is characterised by short, warm summers and very long and very cold, severe winters. The main physical feature of the Taiga is the forests of coniferous trees which range for hundreds of miles. The coniferous tree is best adapted to such an unpromising climate, with branches that shed snow easily and needle-like leaves which provide little resistance to the howling winds that blow across these desolate regions.
The Siberian Taiga has recorded the lowest temperatures outside the Antarctic, a very chilly –68°C (-90°F) at Verkhoyansk. Exceptionally cold winds are largely responsible, bringing bitterly cold air from the Arctic Circle: the lack of cloud cover on clear winter nights only serves to let temperatures fall even lower still.
Despite these factors, temperatures can sometimes reach quite high values in the summer – Verkhoyansk once recorded around 36°C (97°F) – which gives the region a massive contrast in temperature extremes.
These cold, forest regions still contain some of the world's larger wildlife, such as bears, lynx and moose, although civilisation pushes ever outwards into these inhospitable lands their numbers diminish. For man the Taiga regions are still most useful as a source of softwoods to make paper.
Other features in the Climate Zones series:
- Temperate Zone
- Desert Zone
- Tropical Zone
- Polar Zone
- Continental Zone
- Mediterranean Zone
