Potential Source Contribution Function Analysis of High Latitude Dust Sources over the Arctic: Preliminary Results and Prospects

Stefano Crocchianti,Pavla Dagsson Waldhauserová,Silvia Becagli,Beatrice Moroni,Rita Traversi,Mirko Severi,David Cappelletti

doi:10.3390/atmos12030347

Abstract

The results of a preliminary investigation of the dust sources in the Arctic based on their geochemical properties by potential source contribution function (PSCF) analysis are presented in this paper. For this purpose, we considered one year of aerosol geochemical data from Ny-Ålesund, Svalbard, and a short list of chemical elements (i.e., Al, Fe, Mn, Ti, Cr, V, Ni, Cu, and Zn) variably related to the dust fraction. Based on PSCF analysis: (i) four different dust source areas (i.e., Eurasia, Greenland, Arctic-Alaska, and Iceland) were characterized by distinguishing geochemical ranges and seasonal occurrence; and (ii) a series of typical dust days from the distinct source areas were identified based on the corresponding back trajectory patterns. Icelandic dust samples revealed peculiar but very variable characteristics in relation to their geographical source regions marked by air mass back trajectories. The comparison between pure and mixed Icelandic dust samples (i.e., aerosols containing Icelandic dust along with natural and/or anthropogenic components) revealed the occurrence of different mixing situations. Comparison with Icelandic soils proved the existence of dilution effects related to the emission and the transport processes.

Highlights

The Arctic is known to be warming faster than the rest of the world in response to changes in greenhouse gases, aerosols, and other climate drivers, a process called Arctic amplification [1]
High latitude dust (HLD) sources have been found to contribute ~52% and ~39% of the annual instantaneous radiative forcing (IRF) in the Arctic in the bottom of the atmosphere (BOA) and the top of the atmosphere (TOA), respectively, while mineral dust deposited on snow accounts for most (∼99%) of the BOA IRF [5]
The following chemical elements were considered in the potential source contribution function (PSCF) analysis: Al, Fe, Mn, Ti, Cr, V, Ni, Cu, and Zn

Summary

Introduction

The Arctic is known to be warming faster than the rest of the world in response to changes in greenhouse gases, aerosols, and other climate drivers, a process called Arctic amplification [1]. Studies on global and regional air mass atmospheric circulation reveal a significant contribution of dust from high latitude (>60◦ N) sources in the air masses reaching the Arctic [7,8,9]. The amount of this contribution is expected to increase in the future in response to global warming which exposes more ice-free areas to dust emissions. High latitude dust (HLD) sources have been found to contribute ~52% and ~39% of the annual instantaneous radiative forcing (IRF) in the Arctic in the bottom of the atmosphere (BOA) and the top of the atmosphere (TOA), respectively, while mineral dust deposited on snow accounts for most (∼99%) of the BOA IRF [5]. A different impact of dust on IRF can be postulated due to the nature and abundance of the constituent particles, mainly iron oxides [10]

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Conclusion