The optical properties of volcanic dust particles and their effects on the Arctic environment

Taru Fiia Amanda Koivusalo

Bakalářská práce

Abstract:

It is increasingly recognized that light-absorbing impurities (LAI) deposited on snow and ice affect their albedo and facilitate melting processes. Reduced albedo of snow and enhanced melting can lead to less snow cover revealing dark ground underneath, leading to a positive feedback loop. One of the most important LAI is considered to be black carbon (BC), but for some areas volcanic dust has been found to have a larger impact on the snow surface albedo due to high dust emissions. For the Arctic areas, Iceland is one of the most important high-latitude dust sources. This work focuses on studying the optical properties of Icelandic volcanic dust to understand its interaction with the Sun’s radiation and to estimate how this affects the natural areas of dust deposition. Optical properties of Icelandic volcanic dust samples were measured at the laboratory of the Finnish Geospatial Research Institute (FGI) in Espoo, Finland using the latest setup of the FGI’s goniospectrometer. It was found that, depending on the particle size, the albedo of dry volcanic dust on the visible spectrum can be as low as 0.03, which is similar to that of BC. This confirms the previous suggestion that volcanic dust of high latitudes can be comparable to BC as strong LAI and highlighting the importance of Icelandic volcanic dust’s role as an albedo reducing impurity on snow and ice in the Arctic areas. Volcanic- and high latitude dust should be included in studies on climate changes in Polar Regions not only for its absorbing optical properties, but also for significantly higher amounts in the Arctic atmosphere than BC.

Keywords

air pollution, albedo, climate change, cryosphere, optical properties of particles

Jazyk práce: angličtina

Datum vytvoření / odevzdání či podání práce: 3. 4. 2023

Obhajoba závěrečné práce

• Obhajoba proběhla 23. 5. 2023
• Vedoucí: Mgr. Pavla Dagsson Waldhauserová, Ph.D.
• Oponent: Roman Juras, Ph.D.

Česká zemědělská univerzita v Praze

Fakulta životního prostředí

Bakalářský studijní program:
Environmental Engineering