Cities in rain

2008/04/01 Galarraga Aiestaran, Ana - Elhuyar Zientzia

• Klima
• Ingurumena

Some American meteorologists have already realized that there was a certain relationship between rain and cities. Analyzing where and when the basques were produced, it seemed that cities could attract rain. But they did not know how and why it happened.

Meteorologists began to investigate the issue. In fact, if the relationship is demonstrated, it would be very convenient for cities to take into account meteorological prediction software and climate models, for example. In the prevention of floods, for example, it can be of great importance and, in addition, by growing and multiplying the cities, over time its influence on the rains would be even more evident.

Thus, data were collected from the satellites that observe the Earth and it was verified that special phenomena occurred in the surroundings of the cities. This phenomenon was evident, for example, on the coast of the Gulf of Mexico in the United States, in the city of Atlanta.

In the measurements that were made in Atlanta in August, the difference between the interior temperature of the city and that of the environment was about 7ºC on average; in the city, the air temperature was about 27ºC during the day and that of the land of about 49ºC, and in the evening, that of the air was down to 13ºC and that of the earth to 24ºC. In view of these data and the images taken from the satellite, meteorologists concluded that the city itself provoked chaparrones, since the contrast of temperatures caused storm clouds over the city.

The same phenomenon observed in Atlanta occurs in the United States and other large cities in the world. In addition to temperature, there is another factor that relates rain to cities: pollution. What's more, pollution makes weekends more rainy than other days.

Rain weekend of the week

On weekends there are more possibilities to taste the flavor of the rain than the rest of days.

It was also shown that on weekends it rains more in the United States, on the east coast. For this purpose, the data obtained via satellite was also analyzed. In this way, it was confirmed that the day of the week did not affect the torrential rains that were produced on the ocean. That is, on the high sea it rained both Tuesday and Saturday.

On the contrary, coastal (and therefore urban) cities were soaked more often on weekends. The data confirm the perception that on Saturdays it rained 22% more than on Mondays. For once, beliefs were not corrupt.

When the cause-effect relationship began to be sought, the response was found in pollution: contaminating particles in the air in cities store moisture and help create clouds. And as the week passes, the particles accumulate in the air. The highest concentration of particles occurs on Saturdays and is then when the largest clouds occur and explode over the cities.

In any case, it is not easy to know the influence of the factors mentioned in the Basque Country. The cities of Euskal Herria cannot be compared with those of the United States, because they are much smaller. But if the dimensions and densities of the cities continue to increase, it may be possible that the whole Basque Country, or at least the Autonomous Community of the Basque Country, is considered a single city, and perhaps then it will be seen that it rains more… and especially on weekends!

Published in Deia