Atmospheric instrument hitches ride on Antarctic planes

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Audrey Merket, NSF NCAR and UCAR Science Writer and Public Information Officer
amerket@ucar.edu
303-497-8293 

David Hosansky, NSF NCAR and UCAR Manager of Media Relations
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303-497-8611

This November through February, a specialized laser instrument that measures atmospheric gases is hitching a ride on regularly scheduled flights to and from McMurdo Station in Antarctica. The instrument will collect information about how much carbon dioxide is going in and out of the Southern Ocean for a project called the Southern Ocean Carbon Gas Observatory (SCARGO).  

The Southern Ocean plays a crucial role in global weather patterns, but because it is so large, remote, and inhospitable, researchers lack the data to accurately capture its role in computer models. To get a better picture of the carbon cycle in this region of the world, researchers from the U.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR) are leveraging routine flights that transport staff and supplies during the Antarctic summer season. 

“The Southern Ocean is one of the only places in the world where the deep ocean interacts with the atmosphere and because of this, it will play an outsized role compared to other ocean regions in determining the future behavior of the Earth system,” said Britton Stephens, an NSF NCAR senior scientist and lead investigator of the SCARGO project. “We're trying to figure out exactly what is going on in the region and then use that information to make our models better.” 

SCARGO is funded by the NSF Office of Polar Programs. The research is led by NSF NCAR in collaboration with NOAA, the Cooperative Institute for Research In Environmental Sciences (CIRES), [C]Worthy, and Earth Sciences New Zealand. The flights are operated by the New York Air National Guard in support of the U.S. Antarctic Program.

Precious cargo

McMurdo Station is the main U.S. research station in Antarctica, and is situated on the coast of Antarctica south of New Zealand. The station operates year round but is busiest during the Antarctic summer months of October through March. Three times a week during the summer season, SCARGO will take advantage of regularly scheduled flights aboard one of the New York National Guard’s LC-130 aircraft – the only heavy lift aircraft in the world with skis. The flights take place between McMurdo Station; Christchurch, New Zealand; and the NSF Amundsen-Scott South Pole Station and are scheduled based on weather forecasts supported by the Antarctic Mesoscale Prediction System (AMPS), which is another NSF NCAR project funded by the Office of Polar Programs. 

NSF NCAR researchers spent three years iterating on the design for the SCARGO instrument and its installation. Their goal was to create something easy to load that wouldn’t take up valuable space needed for transporting supplies and people. The result is an instrument rack housed inside a compact cargo box on wheels. A laser-based analyzer, a GPS receiver, and a laptop are mounted in the instrument rack. For each flight, the SCARGO instrument will be wheeled on board and nestled into the front of the cargo area, a space that is often empty. 

A tube will extend up through a hatch that was custom designed to safely replace the aircraft’s standard escape hatch. A pump will pull air through the tube that will be analyzed by the instrument. This process allows the SCARGO instrument to observe the concentrations of carbon dioxide and other gases at different heights in order to quantify how they are distributed vertically in the air. These vertical profiles will provide more accurate measurements of carbon dioxide exchange for the Southern Ocean than the small amount of existing data that is obtained from ships and robotic floats in the water. 

NSF NCAR researchers and trained staff will support the measurements from McMurdo, occasionally flying along to the South Pole and back. Because seats to Christchurch and back are in high demand, on these flights, they will load the SCARGO instrument, make sure it’s set up, and then wave goodbye. Separate crews in Christchurch will test the instrument and prepare it to be loaded onto the next flight south. 

The Southern Ocean plays a vital role in regulating Earth’s carbon cycle and moderating global weather patterns. A unique set of currents in the remote location creates an upwelling where deep ocean waters are forced upward. As the water from the deep ocean reaches the surface, it absorbs atmospheric gases, including carbon dioxide. When the water dives back down, the carbon dioxide goes with it and is essentially locked up in the deep ocean for hundreds to thousands of years. 

The exact amount of carbon dioxide the ocean is soaking up and whether that amount is increasing or decreasing is unknown. By the end of the season, the SCARGO team will have a large amount of data that they hope will improve our knowledge of how the Southern Ocean is currently affecting the global atmosphere and how it will continue to influence it. 

“The Southern Ocean is providing a great service to society by taking up a large amount of the carbon dioxide that we're emitting every year,” said Stephens. “But we need to better understand the processes involved to be able to predict whether this uptake is going to stay steady, slow down, or speed up in the future.”

This material is based upon work supported by the NSF National Center for Atmospheric Research, a major facility sponsored by the U.S. National Science Foundation and managed by the University Corporation for Atmospheric Research. Any opinions, findings and conclusions or recommendations expressed in this material do not necessarily reflect the views of NSF.