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In mid-August 2009, ground-based lidar networks on both sides of the Pacific Basin detected an elevated dust layer. A combined analysis by ground-based lidars, spaceb-orne lidar CALIOP, and numerical models revealed that dust particles emitted in the Taklimakan Desert were transported across the Pacific Ocean in 12 to 13 days. This was the first evidence of summertime trans-Pacific transport of Asian dust from the Taklimakan Desert. A large-scale dust storm occurred in the Taklimakan Desert during 12-16 August due to a strong surface wind accompanied by a cold front. Many dust particles were lifted up into the free atmosphere by the upslope wind formed by the steep slope of the surrounding mountains. This dust injection process was analogous to that for springtime cases. The Taklimakan dust was then transported eastward at 6-8 km altitude. This high transport altitude allowed the Taklimakan Dust to be transported beyond the Pacific Ocean without the effect of the southeasterly outflow of the summertime Pacific high. The wind field anomaly at 500 hPa in mid-August 2009 shows increases of northwesterly winds driven by SE-NW pressure gradients around 110-140 degrees E and 180-140 degrees W, indicating that the pressure pattern during the dust event favored the trans-Pacific transport.

Citation: Yumimoto, K., K. Eguchi, I. Uno, T. Takemura, Z. Liu, A. Shimizu, N. Sugimoto, and K. Strawbridge (2010), Summertime trans-Pacific transport of Asian dust, Geophys. Res. Lett., 37, L18815, doi:10.1029/2010GL043995.