Researchers used data on temperature and dust movement on Venus to understand how winds change on this planet. They found that the weather on this planet is quite diverse and strongly depends on the surface landscape.
Atmosphere of Venus
Venus is our closest neighbor, but we still know very little about the conditions on its surface. The reason for this is its extremely dense atmosphere with a thick layer of clouds, which prevent us from seeing what is happening directly above the surface. However, researchers from the Sorbonne have recently been able to shed some light on what is happening with the planet’s weather.
Due to thick cloud cover, scientists know very little about what is happening in the lower layers of the planet’s atmosphere, but they are certain of one thing: the conditions there are hellish, with high temperatures combined with equally high pressure, which prevents Earth-based equipment from operating there for long periods of time.
At the same time, high pressure is combined with strong winds, which means that the latter carry incredible energy by Earth standards. However, at the surface, their speed drops to 1 m/s, which is very low compared to Earth and Mars.
Dust and temperature
The new study of Venusian weather is based on global measurements of just two parameters: temperature and dust concentration, which were measured on Venus. However, these proved sufficient to reproduce a global picture of the weather there.
In particular, it turns out that one of the dominant processes is the movement of gases between the illuminated and shadowed sides of the planet, which is not surprising given that it rotates extremely slowly. A day on Venus lasts 117 Earth days. Therefore, different sides of the planet have time to heat up, cool down, and heat up again, and so the redistribution of heat is expected to be high.
Much more interesting was the discovery that different terrain interacts differently with the atmosphere. This is especially true for the differences between lowlands and highlands. In the tropics, there is a very clear “diurnal shift,” which means that winds blow differently depending on whether it is day or night in a particular part of the planet. At midday, winds blow up the slope (in technical jargon, this is called “anabatic”) due to the heating of the ground beneath them, pushing it upward. However, at night, this process is reversed, as infrared cooling of surfaces causes the air to cool, causing winds to descend the slope, known as “katabatic.”
These processes directly affect surface temperature, as katabatic winds cause descending air to compress, thereby heating it and counteracting infrared cooling from the surface in a process called adiabatic warming. In fact, winds in the mountains maintain a stable temperature, with less than 1 K variation between night and day cycles. This is very little compared to the 4 K variation that is normal for lowlands, which do not have the same cooling effect.
Scientists hope that in the future they will be able to obtain much more data to build a weather model for Venus. After all, the DaVINCI spacecraft is scheduled to travel there in the next 10 years. It is expected to make the first descent into the planet’s atmosphere in several decades.
According to phys.org
