Ozone-enhanced layers in the troposphere over the equatorial Pacific Ocean and the influence of transport of midlatitude UT/LS air

H. Hayashi, K. Kita, S. Taguchi
2007 Atmospheric Chemistry and Physics Discussions  
Occurrence of ozone (O 3 )-enhanced layers in the troposphere over the equatorial Pacific Ocean and their seasonal variation were investigated based on ozonesonde data obtained at three Southern Hemisphere ADditional OZonesondes (SHADOZ) sites, Watukosek, American Samoa and San Cristobal, for 6 years between 1998 and 2003. 5 10 during the periods from February to March and from August to September, while it was relatively low, about 10%, at Watukosek and Samoa. A significant number of the O 3
more » ... number of the O 3 -enhanced layers were attributed to the transport of midlatitude upper-troposphere and lower-stratosphere (UT/LS) air. Meteorological analyses indicated that these layers originated from equatorward and downward transport of the midlatitude UT/LS air 15 masses through a narrow region between high-and low-pressure systems around the subtropical jet stream. This process accounted for more than 40% at Watukosek between May and December, about 60% or more at Samoa all year around, and about 40% at San Cristobal between November and March, indicating that it was important for O 3 budget over the equatorial Pacific Ocean. Abstract ACPD Abstract ACPD Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion EGU OZonesondes (SHADOZ) experiment (Thompson et al., 2003a and 2003b) , and the data are available at the SHADOZ website (http://croc.gsfc.nasa.gov/shadoz/). The data analyzed in this work were obtained between Abstract ACPD
doi:10.5194/acpd-7-17179-2007 fatcat:7g7sz2zjhfe3pldunzkoutgn2y