RESEARCHERS TRACE EVOLVING PACIFIC AIR CHEMISTRY

Spring has arrived in Hong Kong and so have research planes, scientists and a lot of equipment. By studying the seasonal airflow from Asia across the Pacific, NASA scientists believe it is an ideal time to collect information used to study how natural and human-induced changes affect our global climate.

The Transport and Chemical Evolution over the Pacific (TRACE- P) experiment will use two specially equipped NASA aircraft to measure gases and identify the chemical makeup of air off the East Asian coast over the Pacific Ocean.  

The TRACE-P mission, headed by NASA's Langley Research Center in Hampton, VA, starts its 45-day operations this month from Hong Kong and finishes at Yokota Air Force Base near Tokyo.  

In addition to a DC-8 from NASA's Dryden Flight Research Center, Edwards, CA, and a P-3B from NASA's Wallops Flight Facility, Wallops Island, VA, satellites and ground stations will play a role, as scientists gather information to plan flight patterns and interpret measurements taken on the aircraft.  

"While NASA administers the TRACE-P program, it's important to realize all of the expertise that's necessary to make the measurements on these aircraft," said Dr. Jim Crawford, TRACE-P Deputy Mission Scientist and Langley researcher. "We have to bring together researchers from international universities, other government labs and from within NASA to make an adequate assessment of what's happening over the Pacific."  

A major goal of TRACE-P is to understand the chemical makeup and reactions of air coming from Asia. Researchers want to study how the chemical reactions and movement affect the air as it moves away from Asia across the Pacific. With rapid industrialization and increased energy use, mostly in the form of fossil fuel, scientists expect emissions to increase as East Asia continues to develop.  

"Out of all the industrialized regions in the world, North America and Europe are at a much higher latitude," Crawford added. "And since air chemistry is driven by sunlight, the Asian emissions happening at a tropical latitude potentially have a very different chemical evolution."  

TRACE-P is part of the long series of NASA Global Tropospheric Experiments (GTE) and a follow-up to earlier atmospheric science investigations in 1991 and 1994. These exploratory missions studied the Asian outflow -- air flowing over the continent to and across the Pacific -- and how seasons and geography affect the chemistry and movement of air.  

GTE is aimed at a better understanding of worldwide chemistry of the troposphere, which is the part of the atmosphere closest to the Earth's surface. Over the past twenty years, GTE has conducted missions in the Amazon, the Arctic, the tropical Atlantic and the Pacific, to study both natural and man-made processes that determine the troposphere's chemical make-up.  

This international research effort is part of NASA's Office of Earth Sciences Enterprise, Headquarters, Washington, DC. The Enterprise is a long-term research effort dedicated to studying the Earth System and how it is changing due to both natural and human-induced processes.