Asian Dust Transport to Summit, Greenland Explored through Size-Resolved Composition and Trajectory Analysis

Year-round, size- and time-resolved aerosol monitoring at Summit, Greenland using the DRUM sampler began in 2003 and has provided a rich dataset for long-term analysis of compositional trends. Elemental concentrations and ratios during episodic events in boreal spring are consistent with long range transport of dust originating from the Takla Makan and Gobi deserts of Eastern Asia, typically accompanied by anthropogenic components, notably sulfates, zinc and other urban/industrial aerosols, transported with the dust across the Arctic to the Summit site. Historical data from spring 2001 - including the fourth ACE-ASIA experiment and a monitoring campaign on Adak Island, Alaska - were leveraged to estimate fall-off of mineral dust concentrations over distance since equivalent monitoring techniques were employed for the historical and current campaign. The calculated fall-off ratio was explored for multiple aerosol events, particle sizes, and compositional species. Forward and back trajectory analyses are also consistent with long-distance transport from Asia for multiple events. For example, two dust storms originating over the Gobi Desert in spring 2005 resulted in an enhancement of calcium in the 2.5 - 5.0 and 1.15 - 2.5 μm size bins at the Greenland Summit Station. We also saw the signature of the March 31- April 1 2013 event, previously characterized to be comprised of Takla Makan and Gobi desert dusts mixed with industrial pollution approximately 7-10 days prior, lofted to ≥ 4km in height, and after trans-Pacific and trans-North American transport, arriving at Summit. Mineral dust from Asia accompanied by sulfates, zinc and other materials likely derived from urban/industrial sources, dominates total annual aerosol mass at Summit, although periodic incursions of industrial aerosols from North America and Europe are also observed along with incursions of sea salt, wood smoke and rare volcanic aerosols. The results of these analyses independently support previous assertions and give additional insights on the influence, seasonality, and characteristics of East Asian dust transport to Greenland.