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Airborne Chromatograph For Atmospheric Trace Species (ACATS)

Status

Status: 
Retired
Operated By: 
PI
Replaced By: 

Megan Northway, John Holecek, Pavel Romashkin, Dale Hurst, Steve Ciciora

ACATS-IV is a 4-channel gas chromatograph with electron capture detection (ECD) that measures a variety of halocarbons and other long-lived trace gases in the stratosphere. The instrument is currently configured to measure CFC-11 (CCl3F), CFC-12 (CCl2F2), CFC-113 (CCl2FCClF2), methyl chloroform (CH3CCl3), carbon tetrachloride (CCl4), halon-1211 (CBrClF2), chloroform (CHCl3), methane (CH4), and hydrogen (H2) every 125 s, and nitrous oxide (N2O) and sulfur hexafluoride (SF6) every 250 s. Each channel is comprised of a sample loop (2-10 cm3 volume), gas sampling valve (GSV), chromatographic column pair, ECD, electrometer, and several flow, temperature, and pressure controllers. In-flight calibration is carried out every 625 s (1250 s for N2O and SF6) by injecting a dried, whole air standard containing approximately 80% of tropospheric mixing ratios.

Instrument Type: 
Aircraft: 
Recent Missions: 
SOLVE (ER-2 - AFRC); POLARIS (ER-2 - AFRC); STRAT (ER-2 - AFRC); ASHOE/MAESA (ER-2 - AFRC); SPADE (ER-2 - AFRC); AASE2 (ER-2 - AFRC)
Complete mission list:
Point(s) of Contact: 
James W. Elkins (POC; Co-I), Eric Hintsa (Co-I), Fred Moore (Co-I), Brad Hall (Co-I)