Signature of a Pacific Hurricane in the Composition of the Upper Troposphere over Socorro, New Mexico

We present a case study based on ozonesonde measurements during the SEACIONS (SouthEast American Consortium for Intensive Ozonesonde Network Study) campaign in August-September 2013. Ozone vertical profiles from the surface to the lower stratosphere were obtained from balloon-borne instruments on a daily basis from seven stations during SEACIONS. Data from the Socorro, NM site (34N, 107W) show a layer of anomalously low ozone in the upper troposphere (UT) between 8 and 14 km during the period Aug. 8-16. Back trajectories, UT jet/tropopause analyses, and data from the Microwave Limb Sounder (MLS) instrument on the Aura satellite indicate that this feature originated from the marine boundary layer over the eastern/central tropical Pacific. Several disturbances and one hurricane occurred near this location within an active region of the ITCZ during the first two weeks of August 2013. Henriette was a small hurricane that formed over the eastern Pacific and reached category 2 intensity on Aug 6. After weakening and moving into the central Pacific basin on Aug 9, Henriette ultimately dissipated several hundred miles southwest of Hawaii. This hurricane, along with a series of preceding and following tropical disturbances, pumped marine boundary layer air with low ozone (20-30 ppbv) into the UT over a large region of active convection. The outflow was advected to North America 3-5 days later along the flanks of a strong subtropical UT jet, creating a tongue of low ozone that was observed in MLS ozone fields and in ozonesonde profiles from Socorro.