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

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

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

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.