Scientists are exploring the role of sand and dust particles in our climate and weather systems, focusing on a surprising location: Iceland. Unlike typical deserts with orange sandy dunes, Iceland’s vast desert areas—covering 44,000 km²—are flat expanses of black volcanic dust. These areas produce particles known as HLD (High-Latitude Dust), which originate near the Arctic Circle but can travel as far as mainland Europe.
Each type of dust has a unique composition, and Icelandic HLD is primarily made of black volcanic glass. Researchers like Pavla Dagsson-Waldhauserova have found Icelandic black dust in places as distant as Finland and Serbia. The formation of these deserts in Iceland is largely a result of human activity. Viking settlers deforested the land, attempting to cultivate it using unsuitable techniques for Iceland’s colder, windier climate. This led to severe desertification, with only about 2% of the country now covered by forest or woodland.
The climate impact of this dark HLD is significant and differs from that of low-latitude dust like that from the Sahara. While brighter desert dust reflects sunlight, helping to cool the Earth, Icelandic dust absorbs sunlight due to its darker color, warming the land and air. One of the most critical effects is the deposition of HLD on the cryosphere—the glaciers and ice caps. When this black dust settles on glaciers, it reduces their albedo (reflectivity), causing them to absorb more heat and melt faster. This not only accelerates glacier degradation in Iceland but also impacts glaciers in Greenland and Arctic sea ice.
Moreover, the melting glaciers expose more fine volcanic material beneath, providing an “unlimited” source of dust that perpetuates the problem. Dust storms in Iceland are frequent, occurring about 135 days per year, and have led to numerous accidents and health issues like respiratory illnesses.
On the flip side, HLD has potential cooling effects by influencing cloud formation. Airborne dust particles serve as nuclei for ice crystals, which are crucial for cloud development. Clouds play a vital role in the Earth’s climate system by affecting the water cycle and controlling the planet’s temperature through cloud-climate feedback mechanisms. Understanding how HLD contributes to cloud formation could improve predictions of global warming and weather patterns.
To better predict these patterns, scientists like Polly Foster from the University of Leeds are investigating the distribution of dust particles at different atmospheric heights. New technologies, such as meteorological drones equipped with innovative instruments, are being used to collect real-time data on particle size, temperature, pressure, and humidity up to two kilometers above the ground. These drones offer a cost-effective and reliable method to study the atmospheric boundary layer, where energy exchange occurs, and air pollution can be trapped.
This research aims to refine global dust models, which currently lack detailed data on HLD sources or have insufficient resolution. By incorporating in-situ data collected from active dust hotspots in Iceland, scientists hope to improve these models, leading to better climate predictions.
In conclusion, understanding HLD is crucial for predicting global warming and weather patterns. Its unique properties have a dual impact on the climate—accelerating warming through ice melt while also potentially cooling the atmosphere by enhancing cloud formation. Ongoing research and technological advancements are essential to fully grasp the role of high-latitude dust in our climate system and to develop effective strategies for mitigating its adverse effects.