Professor Maurice Tsalefac, Climatologist at the University of Dschang, in an interview throws more light on the current hazy weather in Yaounde.
Q: The current weather condition is foggy. Is it normal for such a condition to be experienced during this period of the year considered as the rainy season?
A: We are experiencing a relatively contrasting climate from the centre to the northern parts of the country and a rainy one especially in the south.
In the centre and the northern parts of the country, the weather is very hot during the day and sometimes very fresh at night. The hot weather condition is linked to the fact that the country is at the equinox and the sun energy is at its maximum at the equator.
This normally must lead to more evaporation and more rainfall in the south of the country and to a contrasted situation in the centre and the northern parts of the country, with sporadic rainfall and hot temperatures. This situation may be aggravated on one side or on another taking into consideration the inter-tropical convergence zone and the thickness of the monsoon.
Should the monsoon be thicker it can lead to a rainy time. The reverse is a very hot weather condition.
Fog is derived from this much-contrasted weather because it is formed when humid and hot air arrives on a cool surface. This is because the monsoon is replaced very rapidly by dry air of harmattan coming from the Sahara region. That is why the weather conditions seem to be abnormal.
Q: What is responsible for this weather condition?
A: The main factors are the revolution of the earth around the sun and the air mass movement. But air masses do not react immediately to the reception of the solar energy by the earth surface. There is always a delay. This situation is complicated by the present climate changes which provoked more evaporation (transpiration) and consequently too much water vapor in the atmosphere. That is why, at times we experience a hot and rainy climate. This is due to the greenhouse effect provoked by the water vapor in the atmosphere but also a very dry weather some days after heavy rains.
Q: What are the effects of such a weather condition on the environment and human beings?
A: The effects are many considering human beings, animals and plants. Rain favours soils degradations, inundations and pollutions. Some animals, species such as birds and insects do migrate during such period. Concerning the plants, some which cannot survive severe conditions are going to disappear and some are going to modify their physiological behavior so too are human beings.
In fact, the impacts may vary from the rural area to the urban area with regards to the capacity of the government to take care of the populations and to prevent disasters and diseases that come with the season.
Q: What advice or precautions should be taken by inhabitants?
A: It is important for the government to continue to take care of the population in spite of the actual context of insecurity which prevails in the country. That is why, it is necessary to continue to rehabilitate the meteorological stations and to create new ones, since our main problem is that we do not have expertise information about the climate the country.
We must also sensitise the population about climatic risks and try to elaborate climate plan at different territorial scales since the effects of the changing climate is fundamentally local.
It is clear that individuals must adapt to the changing climate, by trying to get expert information and related effects of climate change on their activities.
