The volcanic clouds They arise from a volcanic eruption. They often have unique characteristics due to their density and the presence of a layer of burning gases and pyroclastic materials of varying sizes. These clouds are quite dangerous for airspace and often have serious economic consequences.
In this article we are going to tell you everything you need to know about volcanic clouds, their formation and characteristics.
volcanic clouds
During the weekend of April 17 to 18, 2010, a volcanic cloud caught the world's attention. A few days ago, Iceland's Eyjafjallajökull volcano erupted, releasing a thick plume of burning gases and pyroclastic material of various sizes into the atmosphere that drifted eastward, driven by winds, closing off much of Europe's airspace.
The fact that Iceland's volcano has erupted should come as no surprise, as the Nordic country is located in one of the most seismically active regions on Earth. There are several volcanoes in different parts of Iceland, many of which have long eruption histories and are larger than Eyjafjallajökull's eruption. Due to the limitations of the different tropospheric levels, it cannot launch material above 6 to 8 km altitude.
If the column reaches the stratosphere, the powerful airflow that dominates there will cause the ash to spread rapidly across the planet, causing significant global cooling. These types of climate anomalies have occurred throughout history and are sometimes caused by Icelandic volcanoes such as Laki or Hekla. To better understand the dynamics of these eruptions, you can read about the types of rashes that exist and their influence on the formation of volcanic clouds, as well as on pyroclastic clouds which are also formed during volcanic eruptions.
Characteristics of volcanic clouds
Volcanic clouds exhibit some characteristics that distinguish them from conventional clouds. The violent upward ejection of hot material from the volcano immediately created a huge thermal cluster that rose rapidly.
Inside, the volcano spews toxic gases that coexist with water vapor and large amounts of pyroclasts, which are fragments of volcanic rock of various sizes —from the smallest ash, always less than 2 mm in diameter, up to large stones—. They tint the clouds a typical black. Friction against different burning materials creates a charge separation, which often results in lightning in ash clouds, a phenomenon you can explore further in the article on the volcanic lightning and its implications on the behavior of these clouds.
As the cloud increases in height, prevailing winds move it laterally, creating a column that, in the case of Eyjafjallajökull, it stretches thousands of kilometers east into the sky over much of continental Europe.
Since these materials are still confined to the atmosphere in which airplanes fly, and since volcanic particles can negatively affect them (blocking engine exhaust and acting like sandpaper on the flight profile), the authorities, responsible for air traffic, have been forced to gradually limit the amount of air they fly. The free zone, which led to the cascading closure of the airport, left millions of passengers grounded. Despite hearing criticism that the measure is disproportionate and irresponsible, in my opinion, we must applaud the priority given to aviation safety, regardless of possible uncertainty about the impact that volcanic material may have on aircraft.
As the materials remain confined to the levels of the atmosphere where the planes fly, given the possibility that the volcanic particles could have a negative impact on them (blocking the gas outlet of the engines and acting like sandpaper on the flight profiles), the authorities responsible for air traffic were forced to progressively restrict the free zones for the flight, leading to a cascading closure of airports, grounding millions of passengers.
Aviation hazard
The volcanic ash cloud poses a serious threat to the safety of air navigation, which in turn causes huge economic losses. The so-called volcanic ash cloud contains volcanic ash, rock powder, sulfur dioxide, water vapor, chlorine and other gases, as well as trace elements harmful to aviation, especially in the vicinity of volcanic eruptions, in very high concentrations.
The columns of gas, ash and rock ejected from the crater act as condensation nuclei for water vapor in the atmosphere, forming ash clouds. Depending on the strength of the wind, these clouds rapidly affect large areas of airspace on the lee side of the volcano. Their danger lies not only in the damage they cause, but also in the difficulty of avoiding them during flight, since they are not easily distinguished from ordinary clouds.
The ash ingested by the engine in flight consists of a high proportion of silicates, which melt at temperatures below the engine's operating temperature, depositing on the fan blades and inside the engine, causing a loss of thrust or even engine stop. The ash can wear out engine components, windshields and leading edges of aerodynamic surfaces, obstruct Pitot tubes and penetrate air conditioning systems or damage antennas.
This set of adversities could impose significant restrictions on air traffic, requiring rerouting and reducing the number of available aircraft. Aircraft that crashed after encountering ash required repairs and even the replacement of certain parts, leaving them temporarily out of service. To better understand the relationship between ash clouds and atmospheric conditions, we invite you to review the article on how aerosols influence global climate and its effect on cloud formation. You can also check out the article on storm photos taken from airplanes for a different approach to climate phenomena.
How are they detected?
The presence of volcanic ash is detected through satellite images, which makes it possible to locate the ash cloud and determine its extension. However, without the knowledge of the eruption, it is difficult to distinguish ash clouds from other clouds using the usual cloud viewing channels. When Eyjafjallajökull erupted, the ash cloud was not easily detectable at the usual pace, as a deep storm in southern Iceland with a warm branch to the frontal system in the southeastern part of the island outshone the cloud with its appearance. cloudy
I hope that with this information you can learn more about volcanic clouds and their characteristics.
