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UM Scientist Takes Part in Study to Examine Pacific’s “Global Chimney”

By Diana Udel

UM Scientist Takes Part in Study to Examine Pacific’s “Global Chimney”

By Diana Udel
The major field project seeks to better understand the region’s influence on the global climate

MIAMI (January 9, 2014) – A team of scientists, including University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science Professor Elliot Atlas, is headed to Guam next week to study how the remote waters of the western tropical Pacific Ocean shape climate and air chemistry worldwide.

The major field project, called CONTRAST (Convective Transport of Active Species in the Tropics) seeks to better understand the region’s influence on the global climate — including how it may change in coming decades if storms over the Pacific become more powerful with rising global temperatures.

“There are so few measurements of atmospheric composition in this important region of the atmosphere that we expect to be able to significantly advance our understanding with the data we will be able to collect during CONTRAST,” said Elliot Atlas, UM Rosenstiel School marine and atmospheric chemistry professor and a CONTRAST principal investigator.

With the warmest ocean waters on Earth, the western tropical Pacific fuels a sort of chimney whose output has global reach. The region feeds heat and moisture into huge clusters of thunderstorms that loft gases and particles into the stratosphere, where they spread out over the entire planet and influence the climate.

“To figure out the future of the air above our heads, we need to go to the western Pacific,” said Laura Pan, a scientist at the National Center for Atmospheric Research (NCAR) and one of the principal investigators on the field project. “This region has been called the holy grail for understanding global air transport, because so much surface air gets lifted by the storms and then spreads globally.”

CONTRAST, which will be based in Guam, is being coordinated with two other field projects – NASA’s Airborne Tropical Tropopause Experiment (ATTREX) and Britain’s Natural Environment Research Council Facility-funded CAST (Coordinated Airborne Studies in the Tropics) Experiment – in order to give researchers an especially detailed view of the air masses over the Pacific with a vertical range spanning tens of thousands of feet. CONTRAST is funded by the National Science Foundation (NSF) and includes more than 40 scientists from University of Miami, NCAR, NASA, and other universities across the country.

Together, the sensor-laden research flights will provide a comprehensive view of the atmosphere from the ocean surface, where gases produced by marine organisms enter the air, to the stratosphere, more than 60,000 feet above.

As trade winds flow across the tropical Pacific, they push warm water to the west, where it piles up in and near the CONTRAST study region. The waters around Guam have the world’s highest sea surface temperatures of open oceans. They provide heat and moisture to feed clusters of thunderstorms that lift air through the troposphere (the lowest level of the atmosphere) and the tropopause (a cold, shallow region atop the troposphere) and then up into the stratosphere.

The CONTRAST team will deploy the NSF/NCAR HIAPER aircraft, a Gulfstream V jet modified for advanced research that will fly at altitudes between about 25,000 and 50,000 feet. Using spectrometers and other instruments on board, the researchers will measure various chemicals and take air samples across a wide region, both in storm clouds and far away from them. The measurements will be analyzed in conjunction with data from the ATTREX Global Hawk (covering altitudes up to 65,000 feet) and CAST BAe146 (with observations from the ocean surface to about 20,000 feet).

The researchers are planning as many as 16 flights, targeting both towering storms that loft fresh air into the stratosphere as well as collapsed storms to examine the composition of the air that remains lower down, in the troposphere.

While the scientists will have considerable follow-up research to do in their labs, some of the airborne instruments will provide real-time measurements to the team. State-of-the-art models of atmospheric chemistry will help guide the research flights in the field, as well as aid in subsequent analysis of the observations.

About the University of Miami’s Rosenstiel School The University of Miami is the largest private research institution in the southeastern United States. The University’s mission is to provide quality education, attract and retain outstanding students, support the faculty and their research, and build an endowment for University initiatives. Founded in the 1940’s, the Rosenstiel School of Marine & Atmospheric Science has grown into one of the world’s premier marine and atmospheric research institutions. Offering dynamic interdisciplinary academics, the Rosenstiel School is dedicated to helping communities to better understand the planet, participating in the establishment of environmental policies, and aiding in the improvement of society and quality of life. For more information, please visit