Aircraft-based observations and high-resolution simulations of an Icelandic dust storm

Abstract

Abstract. The first aircraft-based observations of an Icelandic dust storm are presented. The measurements were carried out over the ocean near Iceland's south coast in February 2007. This dust event occurred in conjunction with an easterly barrier jet of more than 30 m s −1 . The aircraft measurements show high particle mass mixing ratios in an area of low wind speeds in the wake of Iceland near the coast, decreasing abruptly towards the jet. Simulations from the Weather Research and Forecasting Model coupled with Chemistry (WRF/Chem) indicate that the measured high mass mixing ratios and observed low visibility inside the wake are due to dust transported from Icelandic sand fields towards the ocean. This is confirmed by meteorological station data. Glacial outwash terrains located near the Mýrdal-sjökull glacier are among simulated dust sources. Sea salt aerosols produced by the impact of strong winds on the ocean surface started to dominate as the aircraft flew away from Iceland into the jet. The present results support recent studies which suggest that Icelandic deserts should be considered as important dust sources in global and regional climate models.

The distribution and biogeochemical importance of high‐latitude dust in the Arctic and Southern Ocean‐Antarctic regions

“…[] used the Lagrangian particle dispersion model FLEXPART [ Stohl et al ., ] to model the quantity and dispersion of dust generated from within the Arctic region. FLEXPART has been widely used to provide insight into particle dispersion patterns worldwide and has been applied at high latitudes to individual dust events [ Blechschmidt et al ., ] and the resuspension of volcanic ash [ Thorsteinsson et al ., ] in Iceland. Groot Zwaaftink et al .…”

“…[2016] used the Lagrangian particle dispersion model FLEXPART [Stohl et al, 1998] to model the quantity and dispersion of dust generated from within the Arctic region. FLEXPART has been widely used to provide insight into particle dispersion patterns worldwide and has been applied at high latitudes to individual dust events [Blechschmidt et al, 2012] [Thorsteinsson et al, 2012] in Iceland. Groot Zwaaftink et al [2016] suggest that from 2010 to 2012 dust emissions from land north of 60°N accounted for 1.7-5.3% of global dust emissions (averaging 48 Tg yr À1 ).…”

Ash mists and brown snow: Remobilization of volcanic ash from recent Icelandic eruptions

“…Here we suggest several possibilities: Local effects . Orography can strongly perturb both the velocity and direction of surface winds at a local scale; this orographic influence has been invoked to explain spatial patterns of elevated and suppressed particle flux during previous resuspension events in southern Iceland [ Olafsson , ; Blechschmidt et al ., ]. A documented ash storm in Kirkubaerklaustar on the morning of 6 March [ Morgunblaðið , ] provides key evidence that significant material from the Grímsvötn source region was already in suspension.…”

Quantification of iron-rich volcanogenic dust emissions and deposition over the ocean from Icelandic dust sources

“…However, dust emissions from the Arctic and Antarctic have received increased attention (Arnalds, 2010;Bullard, 2013;Gillies et al, 2013;Muhs et al, 2013). Research shows frequent dust storms in South Iceland moving into the North Atlantic Ocean (Arnalds and Metúsalemsson, 2004; and into the Arctic from Northeast Iceland (Dagsson-Waldhauserova et al, 2013a), and it has been suggested that Iceland is among the world's most active dust sources (Arnalds, 2010;Blechschmidt et al, 2012;Bullard, 2013).…”