CLAES CH4, N2O and CCL2F2 (F12) Global data

Abstract

Zonal mean comparisons of CH4 (for altitude regions above the 1.35 ppmv contour), of N2O (above the 210 ppbv contour), and of F12 (above the 360 pptv contour) with UARS Pre‐launch Climatology and with recent models shows reasonable agreement, and some interesting differences in the details of equatorial uplift and descent near the winter poles, including apparent north ‐ south differences. Prominent features such as the double peaked uplift structure in the April–May SAMS [Jones and Pyle, 1984; Barnett et al, 1985] data are clearly evident in all three CLAES tracers. Contours of SAMS CH4 and N2O occur mostly at higher pressures than in the CLAES data, presumably due in part to increased tropospheric content of these gasses, and/or perhaps some dynamic difference associated with the 15 years time difference between the data sets. The CLAES F12 are the first long time base global data sets. These show more tropical uplift than climatology or models. This might suggest a somewhat shorter lifetime of F12 in the stratosphere than is currently accepted.