Comparison of MkIV balloon and ER-2 aircraft measurements of atmospheric trace gases

On May 8, 1997, vertical profiles of over 30 different gases were measured remotely in solar occultation by the Jet Propulsion Laboratory MkIV Interfe rometer during a balloon flight launched from Fairbanks, Alaska. These gase s included H2O, N2O, CH4, CO, NOx, NOy, HCl, ClNO3, CCl2F2, CCl3F, CCl4, CH ClF2, CClF2CCl2F, SF6, CH3Cl, and C2H6, all of which were also measured in situ by instruments on board the NASA ER-2 aircraft, which was making fligh ts from Fairbanks during this same early May time period as part of the Pho tochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) experime nt. A comparison of the gas volume mixing ratios in the upper troposphere a nd lower stratosphere reveals agreement better than 5% for most gases. The three significant exceptions to this are SF6 and CCl4 for which the remote measurements exceed the in situ observations by 15-20% at all altitudes, an d H2O for which the remote measurements are up to 30% smaller than the in s itu observations near the hygropause.