haze from Sahara Painting the sky in picturesque orange hues makes news every year. windblown dust south. This has implications for both infrastructure (e.g. reducing solar energy production) and human health (causing respiratory problems). But this dust carries with it Radioactive elements accumulated in the territory of Spain According to a recently published study by a group of scientists, and other European countries.
Europe experienced an extreme dust accumulation event in February 2021. This event was an opportunity for scientists to ask people living in certain snow-capped mountain ranges (including the Pyrenees) to launch a citizen science campaign. Take snow samples that are then analyzed for dust. The initiative was led by Marie Dumont of the National Meteorological Research Center in France.
Volunteers and scientists collected 10 x 10 cm2 snow samples across the entire dust sheet in the Pyrenees and European Alps (mainly those stretching across France and Switzerland) from sea level to 2,500 m altitude. They then sent the melted contents to laboratories in Toulouse and Grenoble, France. Samples were filtered and dried to analyze dust particles.
The results were published on: Earth System Science DataIt reveals that 152 snow samples were collected from 70 locations over four weeks. The volume of powder in the samples varies between 0.2 and 58.6 g/m2 depending on the location and Particle size decreased with distance from the Sahara DesertBecause the wind carries the smallest and lightest material farther, the heaviest and largest particles accumulate first.
Dust composition varies with distance
The composition of the dust also changed with distance. iron-containing particles were preferentially deposited closer to the original sourceso much so that the particles analyzed in the Pyrenees contained 11% iron. However, this rate dropped to 2% further north in the Swiss Alps.
Accumulation of dust in ice and snow-covered environments can damage these ecosystems. causes the white environment to darken, resulting in negative albedo feedback. This is because dark colors absorb solar radiation from space and therefore warm the surrounding environment, causing snow to melt. The same happens when wearing black clothes in summer, which causes more heat than white clothes, which helps reflect heat and keeps the person wearing it cooler.
For example, the dust event in 2018 caused a reduction in annual snow cover by up to 30 days.
Cesium, beryllium and lead
Additionally, the fog of February 2021 caused many media outlets to publish that this dust brought with it radionuclides (a chemical element that emits radiation as it decomposes). France’s nuclear weapons tests in the Sahara In the 60s.
Researchers confirmed this statement by analysis. Cesium samples and an increase in this element was detected in the Pyrenees. They also confirmed an increase in short-lived radionuclides. beryllium and leadThey explained that these elements, often associated with radioactive fallout, accumulated on the ground through recent snowfalls containing atmospheric dust.
But, plutonium abundances were not significantly different from background levels What was recorded in the northern hemisphere as a result of nuclear tests conducted by the USA and the USSR in the 50s and 60s.
Dumont and colleagues suggest that the nuclear footprint of this plutonium may differ from those resulting from French nuclear tests in the Sahara in the 1960s due to the use of different fuels and engines. Traces of cesium and lead measured in the Sahara are the global results of these tests carried out by the USA and the USSR, not the French.
Scientists recall that French nuclear tests had only 0.017% of the power of nuclear projects of the USA and the USSR.
The paper’s authors say more work needs to be done to determine how the expected increased frequency of these powder events in the future may affect water supplies, snow and ice melt and runoff, avalanches, and ski resort management.
Reference work: https://essd.copernicus.org/articles/15/3075/2023/
……….
Contact address of the environmental department:[email protected]