Dust cycle is an emerging core theme in the Earth system science. Dust emitted from deserts and disturbed soils can have significant impacts on climate, human health, ecosystems, and biogeochemical cycle. On the other hand, dust emissions can be affected by changes in rainfall, wind speed, and vegetation cover. The impacts of dust are far-reaching because of the global movement of dust. Each year about 60 million tons of dust is imported into North America from both coasts, which is dominated by the trans-Pacific transport of dust with both Asian and African origins. This surprisingly large magnitude of dust import is comparable with domestic emissions in North America. Meanwhile, 43 ~ 58 million tons of trans-Atlantic dust from North Africa is deposited into the Amazon basin every year, providing nutrients needed for maintaining the health and productivity of Amazon rainforest, an important ecosystem in regulating global climate. The trans-Pacific aerosol transport, additional source of particulate pollution for the U.S., increases the surface concentration of fine particulate matter (PM2.5) by a magnitude that is much larger in the west than in the east, because of the geographical proximity and high topography of the west. However, when the influences on meteorology by imported aerosols are also considered, the more populous east shows the PM2.5 increase that is comparable to the west. In this presentation I will discuss how these impacts have been assessed utilizing advanced aerosol remote sensing measurements from the MODerate resolution Imaging and Spectroradiometer (MODIS) and the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP) in conjunction with a regional modeling system. Future research will also be discussed.

Location: Physics Bldg., Room 401