April 1998 Asian dust event: A southern California perspective

Abstract

Abstract. In late April 1998 an extreme Asian dust episode reached the U.S. western seaboard. This event was observed by several in situ and remote sensing atmospheric measurement stations. Dramatic reductions in boundary layer visibility were recorded and the resultant peak backscatter coefficients exceeded prevailing upper tropospheric background conditions by at least 2 orders of magnitude. An analysis of this event is given using lidar vertical backscatter profilometry, concurrent Sun photometer opacity data, and transport modeling. At San Nicolas Island the measured and modeled aerosol optical thickness at 500 nm increased dramatically from 0.15 on April 25 to 0.52 on April 26-27. Volume size distribution on April 27 exhibited a prominent coarse mode at 1-2/•m radius, and single-scattering albedo was observed to increase from 0.90 in the blue to 0.93 in the near infrared. Concurrent lidar observations tracked the evolution of the plume vertical structure, which consisted of up to three well-defined layers distributed throughout the free troposphere.

Particulate air pollution in Lanzhou China

“…This is caused by the transport of the TSP due to dust storms. Recent studies indicate that dust storms originated in the East Asia not only influence air pollution in the origins and their neighboring regions Murayama et al, 2001;Sun et al, 2001;Zhou et al, 2002), but also have a long-distance effect across Pacific by atmospheric circulation (Husar et al, 2001;Tratt et al, 2001;Sun et al, 2001;Laat et al, 2001;Clarke et al, 2001). The major sources of the dust storms are the Gobi desert in Mongolia and northern China and Taklimakan desert in western China (Sun et al, 2001).…”

“…The major sources of the dust storms are the Gobi desert in Mongolia and northern China and Taklimakan desert in western China (Sun et al, 2001). In April 1998, an Asian dust storm proceeded eastward with the west wind across Pacific Ocean and subsided to the surface along the mountain ranges between British Columbia and California (Husar et al, 2001;Tratt et al, 2001;Vaughan et al, 2001). Other reports indicated that there is a positive correlation between dust storm in Hexi Corridor and air pollution in Lanzhou Ding et al, 2001).…”

Saharan and Asian dust: similarities and differences determined by CALIPSO, AERONET, and a coupled climate-aerosol microphysical model

“…Asian dust can be transported over the North Pacific Ocean and reach Midway and North America (Duce et al, 1980;Shaw, 1980;Betzer et al, 1988;Clarke et al, 2001;Husar et al, 2001;Tratt et al, 2001;Huang et al, 2008;Eguchi et al, 2009;Su and Toon, 2009). Asian dust also can be transported over global scales Grousset et al, 2003;Uno et al, 2009).…”

Influence of Long-Range Transport Dust Particles on Local Air Quality: A Case Study on Asian Dust Episodes in Taipei during the Spring of 2002

“…The mineral particles are then transported to Northeastern Asia and usually result in serious deterioration in local air quality (e.g., Iwasaka et al 1983;Hursar et al 2001;Murayama et al 2001;Kim et al 2003). Sometimes, Asian dust transport can even be observed in the North Pacific Ocean and North America (e.g., Duce et al 1980;Shaw 1980;Uematsu et al 1983;Jaffe et al 1999;Mckendry et al 2001;Tratt et al 2001;VanCuren and Cahill 2002). Although the Asian dust particles are carried mostly by westerly winds and spread over the mid-latitudes, a portion of the dust particles can also be transported to Taiwan under the prevailing northeasters of the winter monsoon.…”