What things must happen that the ice age can born?
If we think about birth of the ice age, it is simple matter. It demands to be born only powerful decreasing of temperature and the growth of the rainfall.
From the decreasing of the temperature is indeed thought about, that at the right time was large climate change, every would lasted at the least hundreds of or thousands of years, and during that time temperature would be then decreasing about 4-6 degree. (Esim. in the book "Suomen luonnon kehitys" / Matti Sauramo, p. 19 - has been thought, that in Western Europe, in which nowadays is warmer as in Scandinavia, would temperature been about 8 degrees lower than nowadays. ) Same has been thought about rainfall being much bigger than current times, so that ice age would able to be born.
But such as we notice, is in both of these thought, in other words decrease of temperature 4-6 degree and in the supposed growing of rainfall its own problem. Its indicate next examples:
Decrease of temperature. If we assume, that temperature would have decreased as the mentioned 4-6 degrees, so is ascertain, that it doesn't help in the appearing of ice age, just temperature should decrease at the least 15-20 degrees. If now prevails during the summer two- three week hot weather cycle with 30 degrees temperature, so even though from this would be reduced 20 degrees, so 10 degrees which have remain would generally to melt away accumulated snow during the winter with in the week (when for example in Helsinki (Finland) is average temperature of July 17 degrees and in June and August over 15 degree, so it not mean, that always would be with same level temperature. Thus some on the days the temperature can rise between 25-30 degrees. )
Decisive appear to ice age are cooler summers and not cold winters. Because summers should be continually so cool, that snow not had time melt away during the summers. If this prerequisite not happen, ice ages can not appear.
Growth of the rainfall. Another prerequisite to appear of ice age is sufficient rainfall, which is indeed thought to be current larger, so that the ice age could have born. Mere decrease of the temperature can not birth ice age, but it needs also enough rain.
But if we think about this matter, coming true of this matter in practise is very problematic. This for that reason, that if temperature was before lower, it would be rather reduced radically rainfall as added it, in other words would have gone just on the contrary. This would have arisen mainly from the two maker, which are:
- Firstly colder climate would have itself affected, that evaporation and by way of that rainfall would have reduced. There has estimated, that decrease of 12 degrees temperature would reduce the moisture to the half, whereby also rainfall decrease. Colder air wouldn't thus promoted growth of the rainfall, but it might have been hindrance to it.
- Effect of the cold climate would be also, that it would expand ice cover of the sea (of course also lakes, dikes and also the rivers would be mainly on the ice, and of these then could not flow water to sea or evaporate to air). Growth of the sea ice cover again would have reduced the evaporation of the water and by way of that also the rain, because thre is no more so large area, that water could have evaporated. This decreased rainfall would have thus hampered birth of ice age and is difficult think about, how would got even nearby current rainfall. On the contrary rainfall would be then radically reduce and be much smaller than current rainfalls.
If we think about birth of the ice age, it is simple matter. It demands to be born only powerful decreasing of temperature and the growth of the rainfall.
From the decreasing of the temperature is indeed thought about, that at the right time was large climate change, every would lasted at the least hundreds of or thousands of years, and during that time temperature would be then decreasing about 4-6 degree. (Esim. in the book "Suomen luonnon kehitys" / Matti Sauramo, p. 19 - has been thought, that in Western Europe, in which nowadays is warmer as in Scandinavia, would temperature been about 8 degrees lower than nowadays. ) Same has been thought about rainfall being much bigger than current times, so that ice age would able to be born.
But such as we notice, is in both of these thought, in other words decrease of temperature 4-6 degree and in the supposed growing of rainfall its own problem. Its indicate next examples:
Decrease of temperature. If we assume, that temperature would have decreased as the mentioned 4-6 degrees, so is ascertain, that it doesn't help in the appearing of ice age, just temperature should decrease at the least 15-20 degrees. If now prevails during the summer two- three week hot weather cycle with 30 degrees temperature, so even though from this would be reduced 20 degrees, so 10 degrees which have remain would generally to melt away accumulated snow during the winter with in the week (when for example in Helsinki (Finland) is average temperature of July 17 degrees and in June and August over 15 degree, so it not mean, that always would be with same level temperature. Thus some on the days the temperature can rise between 25-30 degrees. )
Decisive appear to ice age are cooler summers and not cold winters. Because summers should be continually so cool, that snow not had time melt away during the summers. If this prerequisite not happen, ice ages can not appear.
Growth of the rainfall. Another prerequisite to appear of ice age is sufficient rainfall, which is indeed thought to be current larger, so that the ice age could have born. Mere decrease of the temperature can not birth ice age, but it needs also enough rain.
But if we think about this matter, coming true of this matter in practise is very problematic. This for that reason, that if temperature was before lower, it would be rather reduced radically rainfall as added it, in other words would have gone just on the contrary. This would have arisen mainly from the two maker, which are:
- Firstly colder climate would have itself affected, that evaporation and by way of that rainfall would have reduced. There has estimated, that decrease of 12 degrees temperature would reduce the moisture to the half, whereby also rainfall decrease. Colder air wouldn't thus promoted growth of the rainfall, but it might have been hindrance to it.
- Effect of the cold climate would be also, that it would expand ice cover of the sea (of course also lakes, dikes and also the rivers would be mainly on the ice, and of these then could not flow water to sea or evaporate to air). Growth of the sea ice cover again would have reduced the evaporation of the water and by way of that also the rain, because thre is no more so large area, that water could have evaporated. This decreased rainfall would have thus hampered birth of ice age and is difficult think about, how would got even nearby current rainfall. On the contrary rainfall would be then radically reduce and be much smaller than current rainfalls.
