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Influence of the North American monsoon on Southern California tropospheric ozone levels during summer in 2013 and 2014
Author(s) -
GranadosMuñoz Maria Jose,
Johnson Matthew S.,
Leblanc Thierry
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl073375
Subject(s) - anticyclone , troposphere , ozone , environmental science , atmospheric sciences , climatology , tropospheric ozone , monsoon , east asian monsoon , lightning (connector) , lidar , air mass (solar energy) , chemical transport model , meteorology , geology , geography , boundary layer , physics , remote sensing , quantum mechanics , power (physics) , thermodynamics
The impact of the North American (NA) monsoon on tropospheric ozone variability in Southern California is investigated using lidar measurements at Jet Propulsion Laboratory‐Table Mountain Facility, California, and the chemical‐transport model GEOS‐Chem. Routine lidar observations obtained in July–August 2013–2014 reveal a consistent ozone enhancement of 23 ppbv in the free troposphere (6–9 km), when ozone‐rich air is transported along the western edge of the upper level anticyclone associated with the NA monsoon from regions where maximum lightning‐induced NO x production occurs. When the high‐pressure system shifts to the southeast, a zonal westerly flow of the air parcels reaching the Table Mountain Facility (TMF) occurs, prohibiting the lightning‐induced ozone enhanced air to reach TMF. This modulation of tropospheric ozone by the position of the NA monsoon anticyclone could have implications on long‐term ozone trends associated with our changing climate, due to the expected widening of the tropical belt affecting the strength and position of the anticyclone.