Summertime Shuttle Plume Transport to the Arctic Using Lower Thermospheric Wind Observations

Recent observational evidence indicates that space shuttle main engine water vapor exhaust can travel to the Arctic and create polar mesospheric clouds (PMCs). If this phenomenon is repeatable, then hundreds of metric tons of water vapor could be ushered into the Arctic lower thermosphere every summer from the shuttle and other mid-latitude launches worldwide. The shuttle-PMC link is a stringent test of our understanding of constituent transport near 110 km. We address it by compiling satellite observations of lower thermospheric winds from NASA's Upper Atmospheric Research Satellite (UARS) for use in a parcel advection model that includes effects of season, altitude, local time and latitude. We find that satellite wind climatologies yield plume motion in the direction observed but significantly slower than inferred from our observations. Reported peak wind speeds from chemical release experiments are generally higher than those from satellites in the 100-110 km region. If wind speeds are as high as the chemical release data indicate, the inferred plume motion can be reproduced. We use recent summertime shuttle plume observations from a microwave instrument measuring water vapor in the Arctic to help constrain the transport.