At http://phys.org/print312139726.html … we learn that Venus behaves strangely as a result of the solar wind, almost as if it has the hiccups or is burping. Giant perturbations, dubbed 'hot flow anomalies' are caused by the solar wind interacting with the atmosphere of Venus. They seem to pull the upper layers, the ionosphere, upwards, causing undulations and stretching the atmosphere outwards. The solar wind impacts with the ionosphere of the Earth but the effects on Venus are more dramatic. The whole planet is affected and they can happen many times in a day. The NASA spokesperson says Venus does not have a magnetic field to protect itself – which is why the solar wind has such a large effect.
The paper is published in the Journal of Geophysical Research (February, 2014) and is based on ESA data from the Venus Express spacecraft. Earth, it seems, is protected from the solar wind by its magnetosphere. Why doesn't Venus have a magnetosphere- what is lacking on Venus.