With the help of instruments and ground sensors on the International Space Station, researchers from the Institute of Astrophysics of Andalusia detected the simultaneous emission of blue flashes and radio pulses in storm clouds for the first time. These rare events are caused by discharges formed by plasma filaments or ionized air. These discharges are not as hot as lightning, but cold.
A series of electrical phenomena that occur in our atmosphere has never stopped growing. This phenomenon has been considered for centuries to include only various types of lightning that occur during storms.
About thirty years ago Transient light event (TLE, Because of its English abbreviations, such as “elves” or ultraviolet halo, “duentes” are shaped like carrots and jet Bruce), a series of very fast lightning events related to lightning, usually occurring tens of kilometers above the clouds.
1994 Ground Gamma Ray Burst (TGF), This is the most dramatic phenomenon in the earth’s atmosphere. They originated from the top of storm clouds, an unexpected discovery, because since then, people have always believed that gamma radiation only comes from outer space.
Now, a study led by researchers from the Institute of Astrophysics of Andalusia (IAA-CSIC) has been published in Journal of Geophysical Research-Atmosphere, Confirm that there is some type of cold discharge in the cloud (not as hot as lightning).As a result, they happen at the same time Blue flashing and pulse broadcast, The author has been able to detect.
These broadcasts or events (Narrow bipolar event o NBE Speaking in English) The nature from the clouds is bipolar (radio pulses have obvious rise and fall), they are very fast, and the first discovery dates back to the 1980s.
He emphasized: “Until recently, a 2016 study showed that these bipolar pulses may be the result of very fast processes characteristic of cold discharges, that is, unlike lightning, those processes that do not heat the surrounding air.” Sergio Soler, IAA-CSIC researcher led the investigation.
He continued: “But its origin is still uncertain.” In 2013, the FORTE satellite detected a series of flashes that appeared to be related to these bipolar radio pulses, but it was impossible to determine whether they were lightning or other types of discharge.”
Unknown settlement in the Indonesian sea
Research conducted by the Atmospheric Power Group (TRAPPA) of the Institute of Astrophysics of Andalusia has solved this problem by simultaneously detecting blue flashes in storm clouds and bipolar radio pulse emission for the first time.
The flash of the study occurred in a severe electric storm that occurred in Indonesia in 2019. The radio records were obtained by researchers from China at ground-based sensors located in the Strait of Malacca, and optical observations were made using ASIM instruments, which were installed on the International Space Station.
The estimated source heights based on radio and optical signals are consistent, and indicate that the source of the blue flicker is in Between 8.5 and 14 kilometers, In the clouds reaching an altitude of 14 to 15 kilometers.
The lack of brightness in the typical ray range allows the author to confirm that, in fact, they correspond to a cold natural discharge, which is suspected of forming and existing in storm clouds.
Point out: “Our data shows that these are cold discharges, formed by ionized air or plasma filaments. Although the air temperature is ambient temperature, the temperature of the electrons is very high, exceeding 70,000 degrees.” Francisco J. Gordillo Vazquez, IAA researchers are responsible for coordinating research.
“Specifically, they will be downloads of that type Corona (They have this bright halo appearance), when studied in the laboratory, they are characterized by their filamentous appearance and blue (they emit blue and near-ultraviolet light), and are also produced under daily conditions, such as The scientist explained in the high-power power cord.
These types of discharges show a huge thermal imbalance of up to tens of thousands of degrees between the temperature of the ambient air and the temperature of the electrons in the plasma filament. Therefore, they can activate special chemical reactions in the atmosphere.
Therefore, although lightning (or thermal discharge) produces nitrogen oxides and some ozone, these cold discharges produce a large amount of Nitrous oxide and ozone, The gas that causes the greenhouse effect.
Gordillo said: “The global warming potential of nitrous oxide is about 300 times higher than that of carbon dioxide, and it tends to eliminate ozone in the environment, so it is important to accurately quantify and understand its source and absorption in the atmosphere.”
These flashes solved the origin of the bipolar radio pulse, but caused a series of questions about the characteristics of corona discharge in the cloud, its formation process, time dynamics, and possible chemical effects on our atmosphere.
This group of authors said: “Observations show that the blue flicker comes from cold ionization waves, called Ribbons Or “darts or ribbons”, and positive NBE is a corona discharge formed by many darts.”
Two different bluish phenomena
Gordillo clarified that these bluish flashes are jet Appearing in the clouds, “seems to be caused by the unstable charge in the storm cloud caused by the cloud lightning that occurred not long ago in the storm cloud (this is the accepted explanation today). injection”.
He emphasized: “However, what we are detecting now is an electric discharge that occurs in a storm cloud, and it may have a vertical dimension of several kilometers (several hundred meters wide). Even so, the ultimate cause of blue is the same, that is That said, although it actually emits between near-ultraviolet light and blue, the plasma dart does not heat the air and emits a characteristic blue color.
“Our work makes it possible to map the amount of corona-type discharges in the cloud, under what circumstances (or in an electrical environment) and their global geographic distribution (where they occur). Gordillo concluded: “We have Working hard, but today is little known. “
S. Soler et al. “ASIM’s blue optical observations of narrow bipolar events indicate corona streamer activity in thunderstorms.” Journal of Geophysical Research: Atmosphere, 125, e2020JD032708. https://doi.org/10.1029/2020JD032708