Scientists, using the nation's newest and most capable aircraft for environmental research, launched a far-reaching field project to study plumes of airborne dust and pollutants that originate in Asia and journey to North America. The plumes are among the largest such events on Earth, so great in scope that scientists believe they might affect clouds and weather across thousands of miles while playing a role in global climate.

The PACDEX (Pacific Dust Experiment) project was led by scientists at the National Center for Atmospheric Research and Scripps Institution of Oceanography. NCAR's main sponsor, the National Science Foundation (NSF), provided most of the funding. The project continued for almost two months.

A. Video interview with V. Ramanathan of the Scripps Institution of Oceanography.

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Ramanathan, a principal investigator on the Pacific Dust Experiment (PACDEX), discusses how the massive plumes of dust and pollantants from Asia may affect global warming. (©UCAR, photo by Carlye Calvin, Video by Jeff Alipit.) News media terms of use*

B. Video interview with Jeff Stith of the National Center for Atmospheric Research.

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Stith, a principal investigator on the Pacific Dust Experiment (PACDEX), discusses how the dust and pollutants can interact with clouds. (©UCAR, photo by Carlye Calvin, Video by Jeff Alipit.) News media terms of use*

C. Satellite view of Asian dust near California

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This April 15, 2001, NASA satellite image shows dust arriving in California from Asian deserts. Concentrations of dust are visible to the south, near the coastline (lower right of image); to the west the dust is mixed with clouds over open ocean. This dust event caused a persistent haze in places like Death Valley, California, where skies are usually crystal clear. (Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE.)

D. Satellite view of Asian dust over the Pacific

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This NASA satellite image, taken on April 30, 2005, shows a plume of dust flowing from China to the north of the Korean Peninsula and over the Sea of Japan.The dust almost completely obscures the island of Honshu from satellite view. Such plumes can cross the Pacific and scatter dust across the Western United States.(NASA images created by Jesse Allen, Earth Observatory, using data obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Goddard Earth Sciences. (Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE.)

E. Readying HIAPER, the G-V research aircraft, for PACDEX

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NCAR engineer Kurt Zrubek (left) and aircraft mechanic Robert Beasley attach part of a pylon mount on a wing of the NSF/NCAR Gulfstream V. The pylon will hold research instruments under the airplane's wing. (©UCAR, photo by Carlye Calvin.) News media terms of use*

F. Behind-the-scenes, preparing for PACDEX

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James Nolan, an aircraft mechanic at NCAR, works on a mount that will hold an instrument package on the fuselage of the NSF/NCAR Gulfstream V. The instruments will help scientists measure solar radiation in the atmosphere. (©UCAR, photo by Carlye Calvin.) News media terms of use*

G. Hypothetical PACDEX flight map

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This illustration shows a hypothetical plume and possible series of flight patterns during the PACDEX field project. When a major plume of dust and pollutants begins blowing off Asia, the G-V would fly from Boulder to Anchorage, where it would refuel, and then fly on to Yokota Air Base, Japan. It would then conduct a series of flights for about a week in and around the plume as the plume moves over the ocean to North America. (©UCAR, illustration by Steve Deyo.) News media terms of use*

G-2. Flight path during the live chat with scientists

H. Satellite measurements of Asian dust across the Pacific

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This image, drawn from satellite observations, shows the movement of a particularly large dust plume from Asia to North America in 2001. The purple and blue areas represent no or little dust in the atmosphere; the yellow and orange areas represent a moderate to high amounts of dust. The image uses a scientific measure known as aerosol optical depth, which shows how much light in a column of the atmosphere is blocked by airborne particles. The observations were taken by the Moderate Resolution Imaging Spectroradiometer (MODIS), flown aboard NASA's Terra satellite. (Image courtesy NASA.)

I. (a) HIAPER, the NSF/NCAR Gulfstream V in flight above mountains

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The NSF/NCAR Gulfstream V in flight over the western United States. (©UCAR.) News media terms of use*

I. (b) HIAPER, the NSF/NCAR Gulfstream V against mountain backdrop

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The NSF/NCAR Gulfstream V at Bishop, California. (©UCAR.) News media terms of use*

J. The NSF/NCAR Gulfstream V: interior

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(©UCAR.) News media terms of use*

K. The NSF/NCAR Gulfstream V: interior

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(©UCAR.) News media terms of use*

L. The NSF/NCAR Gulfstream V: interior

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(©UCAR.) News media terms of use*

M. The NSF/NCAR Gulfstream V: in flight, shortly after takeoff

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(©UCAR.) News media terms of use*

N. The NSF/NCAR Gulfstream V: wing-mounted sensors

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(©UCAR.) News media terms of use*