Snow-capped mountains on the equatorial line
Mount Kilimanjaro in northeastern Tanzania in eastern Africa, at 5,895 meters above sea level, is the highest peak in Africa, located on the equatorial line, and the summit is covered with snow all year round, making it difficult to see its true face.
Coincidentally, The Cotopakchi Volcano in South America, in Ecuador, is located on the equatorial line at 5897 meters above sea level, the peak of the Andes Mountains and the highest point on the equatorial line. The mountain is more than 4700 meters above the year-round snow, and the eastern slope is facing the Atlantic trade wind, and the snow is large and the snow is thick.
Why is it that in this tropical region where the equator is located, the climate is humid and hot, and the green trees are thick, there is snow all year round? The solar radiation at high altitude is much stronger than the ground, so why is it colder than the ground at high altitude?
Anyone who lives in a mountain or climbs a mountain knows that the mountain is colder than the mountain down; and the higher the mountain, the lower the temperature at the top of the mountain, and the greater the temperature difference between the upper and lower levels. Meteorological observations have also shown that within the troposphere below 12 km, temperatures decrease with altitude, typically by about 6°C for every 1000 metres of increase.
In fact, the increase in temperature is not mainly the result of the direct action of solar radiation, but mainly due to the long-wave radiation emitted by the ground after absorbing the short-wave radiation of the sun. Generally speaking, when solar radiation called short-wave radiation passes through the atmosphere, part (about 42%) is reflected by clouds and returns to space; part (about 15%) is absorbed by air to increase air heat; and the other part (about 43%) reaches the ground directly through the atmosphere. The ground absorbs solar radiation to obtain heat and then emits long-wave radiation into the atmosphere. Therefore, the heat obtained by the air comes from both the short-wave radiation of the sun and the long-wave radiation of the ground. In addition, the condensation of water vapor can also make the air obtain heat.
However, relevant expert studies have shown that the heat obtained by air from short-wave radiation and water vapor condensation in solar radiation is one order of magnitude smaller than that of ground-based long-wave radiation. That is to say, although the former two have an effect on air heating, they are much smaller than the latter. Therefore, the heating of the air mainly relies on the long-wave radiation of the ground.
Knowing this, it is not difficult to answer the question. The long-wave radiation emitted by the ground during the day is continuously absorbed by the near-ground air and heats the air, so the closer to the ground the air layer obtains the more long-wave radiation, the higher the temperature; and as the height of the ground increases, the ground long-wave radiation becomes weaker and weaker, and the air there obtains less and less long-wave radiation, and the temperature is getting lower and lower. This is the reason why the top of the mountain, the high altitude is colder than the ground.
Because Mount Kilimanjaro and Mount Cotopakhi are nearly 6,000 meters above sea level, exceeding the height of the snow line of 4,000 meters, the wonders of snow-capped tropical equatorial snowy mountains have emerged.
Penguins on the equatorial line
The penguin is the symbol of Antarctica, how can it live on the equator? However, the Galapagos Islands, located near the equator in the eastern Pacific, are truly inhabited by wild penguins.
The Galapagos Islands, also known as the Colon Islands, belong to Ecuador and have 13 larger islands and hundreds of smaller islands with a total area of about 7,800 square kilometers. Deeply affected by the Peruvian cold current, the temperature is cool and very dry, and there is no tropical landscape of green trees, wind and sunshine, but it is quite cold temperate. The archipelago's most famous wildlife is
。 In 1835, Darwin took the navy cruiser HMS Begle to the archipelago for a scientific expedition that had an important influence on his theory of evolution.
The Galapagos Islands are now home to thousands of wild penguins whose origins are "suspicious". It is thought that several Antarctic penguins may have been washed into the archipelago with the westerly wind drifting and the Peruvian cold current. Due to the influence of the peruvian cold current, the climate is quite cold, and these "Antarctic immigrants" can survive and reproduce. Thus, this spectacle on the equatorial line was created.
People frozen to death on the equatorial line supposedly say that the equator should be the hottest place on earth, but there is
The strange story of the frozen man happens.
In February 1908, under the leadership of Baron Eggers von Kirffertainin
A 40-man expedition climbed Mount Kalisimbi on the Gallengaren Peak in Rwanda, Africa.
The volcano is 4507 meters above sea level, which is higher than the snow line. At noon on the top of the equatorial line, they endured intense sun exposure and at the same time were invaded by cold air. After 6 o'clock in the afternoon, there was a sudden and violent wind like the South Pole. 20 of the expedition team were frozen to death in the bright light of the equator, which became a major curiosity in the history of the world and the history of exploration.
Glaciers on the equatorial line
Kilimanjaro not only has year-round snow, but also has many glaciers. The summit is a crater about 2,000 meters in diameter, with temperatures below 0°C all year round, with lows of minus 34°C and all year round covered in snow and ice. The ice peaks around the crater are steep, and there are many cylindrical ice cubes that do not change all year round, some of which are hundreds of meters high and more than 30 meters wide, like a huge ice tower standing on the top of the mountain, which is very spectacular from a distance.
The glaciers that have accumulated on the top of this mountain are constantly sliding down the slopes of the mountain under the action of the Earth's gravity. The slopes of the mountains have been eroded by millions of years of ice, forming many winding valleys of varying shades, and many valleys come together to form huge wide valleys.
A large number of glaciers overflow from the ice body and flow along the valley, like frozen glaciers, slowly flowing out of the valley. Due to the higher temperatures below the snow line, the glaciers are constantly melting into ice cubes, and the ice cubes collide with each other in the flowing water, making a crisp sound. midday
The snow and ice on the mountain shine brightly under the strong light, and the scene is quite spectacular.