Frequency and Impact of Summertime Stratospheric Intrusions over Maryland during DISCOVER-AQ (2011): New Evidence from NASA's GEOS-5 Simulations.

ABSTRACT: Aircraft observations and ozonesonde profiles collected on July 14 and 27, 2011, during the Maryland month-long DISCOVER-AQ campaign, indicate the presence of stratospheric air just above the planetary boundary layer (PBL). This raises the question of whether summer stratospheric intrusions (SIs) elevate surface ozone levels and to what degree they influence background ozone levels and contribute to ozone production. We used idealized stratospheric air tracers, along with observations, to determine the frequency and extent of SIs in Maryland during July 2011. On 4 of 14 flight days, SIs were detected in layers that the aircraft encountered above the PBL from the coincidence of enhanced ozone, moderate CO, and low moisture. Satellite observations of lower tropospheric humidity confirmed the

SUBMITTER: Ott LE 

PROVIDER: S-EPMC6999667 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature