#Saharandust (
#Saharanairlayer (
#SAL)) over
#Germany during the
#Easter holidays and its significance for the
#weather and
#ecology.
#Photos taken on Easter Sunday 2024 in
#Berlin's popular
#Mauerpark park. About the background to the expensive renovation work there.
Saharan dust is created due to the extreme ground temperatures of the world's largest dry desert, which stretches along Africa's Atlantic coast. Thermal turbulences drive the dust to high altitudes of up to 5000 m, where the particles, which have been ground down to fine sizes between 1 and 74 µm by soil weathering, can remain for months. They reach South America through the trade wind drift. Due to strong south-southwest currents that precede Mediterranean lows, Saharan dust also reaches Europe, which usually happens in spring or autumn and up to fifteen times a year. The
#Sahara dust air masses that reached Germany around the Easter holidays 2024 were described in various media as being stronger than usual, which is why the phenomenon could be seen for days, particularly clearly in West Germany, but also in Berlin. The greatest intensity across Germany was reached on Easter Saturday. On Easter Sunday the phenomenon could still be seen in the form of a milky, cloudy sky and a corresponding veil over the sun.
Saharan dust has various effects on weather and ecosystems worldwide, which are by no means predominantly negative. Sahara dust is actually very rich in nutrients. It is a fallacy to believe that desert sand is hostile to life. The hostility to life in a desert like the Sahara lies in its dryness and heat. The sand, on the other hand, was created from the remains of the bottom of a huge freshwater lake that was there until after the Würm Ice Age (around 10,000 years ago). The
#sand therefore contains valuable
#nutrients, such as magnesium and calcium. Due to its
#globaldistribution, desert dust may make a significant contribution to the
#nutrientsupply of forests, especially the
#Amazonrainforests or the forest areas on the Iberian Peninsula. On the other hand, the
#aerosols containing the dust are suspected of promoting the formation of
#hurricanes over the Mid-Atlantic, for which they could act as condensation nuclei. In connection with
#globalwarming, scientific considerations are also being given to the extent to which the temperature e.g. in South America or Europe could be influenced by the
#dustyair.
The authors J.F. Kok et al. (2018) have dealt with the influence of the
#globaldustcycle and the
#climatesystem in the form of a theoretical framework, and although it is unclear what exactly this influence is, the authors consider it likely that the future
#climate in different areas of the Earth such as North Africa, the Sahel or Central Asia could be influenced by the dust cycle. However, many variables related to the impact of Saharan dust are still unknown. Therefore, the authors M. Dumont et al. (2023) investigated the question of the spatial
#depositionpattern of Saharan dust in the form of a citizen science campaign, for which they were provided with samples from 70 different locations, mostly in high mountains. The authors noted, among other things, "a decrease in deposited mass and particle sizes with removal of the source along the transport route."
The attached photos were taken by me in the famous Berlin park "Mauerpark" in the Prenzlauer Berg district, a
#greenspace along a former GDR border strip that is very heavily visited on summer days. Now a huge
#constructionsite represents an ambitious and expensive redesign concept as part of
#urbangreening and species protection that is scheduled to be completed by 2027.
©
#StefanFWirth Berlin March 31, 2024
Sources
J.F. Kok et al. (2018)
doi.org/10.1038/s41467-017-0…
M. Dumont et al. (2023)
doi.org/10.5194/essd-15-3075…
Article in "Morgenpost" about the new Mauerpark by T. Schubert (2022)
morgenpost.de/bezirke/pankow…
Photos: Saharan dust over Park Mauerpark in Berlin, 31 March 2024, ©Stefan F. Wirth