Presentation on theme: "Unresolved issues for the observations paper 1.CO 2 effects on SSU channels (details; how does this work for the off-nadir x-channels?) 2. Weighting functions."— Presentation transcript:
Unresolved issues for the observations paper 1.CO 2 effects on SSU channels (details; how does this work for the off-nadir x-channels?) 2. Weighting functions for 36x, 47x 3.Remaining differences between SSU15x and radiosondes 4.Are we happy with longer term radiosondes? 5.Ditto for SSU vs HALOE and lidar 6.Need to decide on synthesis points
A stratospheric ozone profile data set for 1979-2005: variability, trends, and comparisons with column ozone data Randel and Wu, JGR, 2007
Key points (for synthesis) Lower stratosphere: 1.Improved understanding of data uncertainties 2.good agreement between MSU4 and radiosondes, if stations with jumps are omitted. 2.lower stratosphere trends are relatively flat vs. latitude 3.strong polar cooling in spring and summer (well known) 4.SSU15x shows systematic differences vs. sondes (and MSU4) (very little cooling in tropics disagrees with other data) 5.Long-term trends show cooling in all data sets, but the magnitude varies. Estimates from data omitting radiosondes with jumps are perhaps best.
Middle/Upper stratosphere: 1.Discussion of SSU data and uncertainties 2.CO 2 changes are important for SSU trends 3.CO 2 adjusted SSU data show trends increase monotonically from lower to upper stratosphere. 4. Temperature changes are not monotonic: volcanoes and step-like changes. Temps have been relatively constant for 1995-2005. 5. Remarkable time variations near stratopause: strong cooling for 1979-1995, warming thereafter (minimum for 1995-1997). 6. Little latitudinal variation below stratopause. Largest cooling at polar latitudes for SSU47x (but WF changes vs. latitude). 7. Reasonable agreement between SSU and HALOE (1992-2005), and between SSU and lidars (but a lot of sampling variability in lidar data). 8. Solar cycle evident throughout tropical stratosphere.