Global warming on the surface of the Earth, both on land and in the sea, is responsible for the violent summer storms that are often accompanied by hail and strong winds, Patras University physics professor Athanassios Argyriou told the Athens-Macedonian News Agency (ANA) in an interview published on Saturday.
Argyriou, who works in the university’s atmospheric physics department, said this warming was beginning to become intense at this time and was linked to the hot, humid and rainy weather that had been observed in June in recent years, with climate change intensifying the weather phenomena.
“The intense warming of the Earth has two consequences: The heat, on the one hand drives the hot air on the surface to greater heights in the atmosphere, similar to the way a hot-air balloon works, and, on the other hand, it greatly increases the evaporation of water from the surface of the Earth, so that the rising hot air drags up large quantities of water vapour,” he explained, noting that this was usual.
Academic Christos Zerefos concurred that climate change was behind the phenomena in statements to ANA: “We are now at the peak of the season. We have something more than the anticipated number of lightning bolts for the summer. The one and only explanation is the destabilisation of the climate.”
Zerefos, who is due to present evidence on climate change at a lecture in the United States in the coming days, though he did not wish to elaborate, said the intensity of the weather phenomena reflected the extent of climate destabilisation.
Argyriou also explained the reasons for the weather patterns observed: “At the start of the summer, the temperature close to the surface of the Earth is higher but the upper atmosphere has not yet had time to heat up accordingly. As a result, the temperature at higher altitudes drops sharply, something that meteorology defines as atmospheric instability. In conditions of instability, the rising masses of warm air accelerate significantly, meaning that they very quickly reach a colder environment and the water vapour they contain becomes liquid. This is the reason that, before a storm breaks out, we have the appearance of dense clouds with so-called vertical growth, expanding upwards rather than horizontally. When condensation reaches the point where upward movement can no longer keep the droplets that form the clouds aloft, it begins to rain.”
This rain becomes a storm, he added, when the quantity of water vapour carried in the air is greater due to the high temperature on the surface of the Earth, resulting in heavy rain that is made up of a very large number of cool rain drops that, in their passing, also drag down cold air masses from their environment, so that this contact cools the air even further.
“This air, reaching the surface of the Earth, is spread in all directions with great intensity, so that we have a squall,” Argyriou added.
He predicted that the specific phenomenon will continue in the greater part of the country for this weekend at least, though any forecast beyond that time cannot be safely made.
Asked whether similar weather patterns have been observed in the recent past, Argyriou told ANA that the phenomenon was seen every year, especially in Western Greece and at a high altitudes.
“It usually occurs around the end of May or early June and lasts about 10 days but there is nothing to prevent its occurrence during the rest of the summer months or in September,” he said, noting that the Patras Gulf region had seen similar weather patterns in August a few years ago that had lasted the entire month.
