2004/12/03 by Laura L. Pan, William J. Randel, B. L. Gary +2 · 1 citation
Earth and Planetary Sciences · Environmental Science · #Atmospheric Ozone and Climate #Atmospheric chemistry and aerosols #Atmospheric aerosols and clouds #Tropopause #Troposphere #Extratropical cyclone #Stratosphere #Atmospheric sciences #Environmental science #Trace gas #Climatology #Lapse rate #Water vapor #Jet stream #Jet (fluid) #Geology #Physics #Meteorology #Thermodynamics
paper · doi:10.1029/2004jd004982
openalex publication_date 2004/12/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Definitions of the extratropical tropopause are examined from the perspective of chemical composition. Fine‐scale measurements of temperature, ozone, carbon monoxide, and water vapor from approximately 70 aircraft flights, with ascending and descending tropopause crossings near 40°N and 65°N, are used in this analysis. Using the relationship of the stratospheric tracer O 3 and the tropospheric tracer CO, we address the issues of tropopause sharpness and where the transitions from troposphere to stratosphere occur in terms of the chemical composition. Tracer relationships indicate that mixing of stratospheric and tropospheric air masses occurs in the vicinity of the tropopause to form a transition layer. Statistically, this transition layer is centered on the thermal tropopause. Furthermore, we show that the transition is much sharper near 65°N (a region away from the subtropical jet) but spans a larger altitude range near 40°N (in the vicinity of the subtropical jet). This latter feature is consistent with enhanced stratosphere‐troposphere exchange and mixing activity near the tropopause break.