1. Observation issues I Changes in constituents? Strat water vapour, ozone, solar cycle changes in ozone? (CO2??); disentangling solar and volcanic signals – OK? Do we believe satellite trends? Are we confident in how satellite data have been merged? MSU4 - weighting function? Lower stratosphere – sonde versus satellite? Do we understand reason for differences in decadal trends? Are the radiosonde data in need of more adjustment, or it a problem with the satellite (e.g. weighting function)? Why are timeseries discontinuous (and is this feature still in the adjusted data)? Lower stratosphere – tropics versus extratropics (difference between satellites and sonde zonal structure) Are the meridional trend differences themselves significant? Seasonal dependence of trends

2. Observation issues II Is the break in the trend in SSU data in the mid-1990s real? In lower stratosphere, steps versus linear trends; are steps real? what do these say about the mechanisms? Or use the mechanisms to define the steps? In upper stratosphere, is temperature trend more of a slave to ozone change than we think it should be? Natural variability – do we need external forcings to explain trends? Are we confident in SSU/AMSU merging (and that NOAA14 is better than NOAA11)? (Cant do 47X from AMSU!) Do we believe the mid-stratosphere (6 hPa) lack of cooling in SSU?

3. Observation issues III Rocketsonde data: need to compare with SSU. New analyses of Russian data (size of lower mesosphere trends??) Lidar data: can we see the SSU break in the trend in the upper stratosphere? Comparison of OHP with California lidar? Can the SSU data be reanalysed to give longitudinal resolution? Is it worth the effort? Where is the raw radiance data to check the SSU overlap?? Check with John Nash. Is the current monitoring of stratospheric temperatures adequate? Do we want to articulate this in our work.

4. Longer term issues Observational: Data rescue on raw SSU data (contact John Nash) Individual AMSU channels (even though short). Is flattening out in all channels? But problems of lack of overlap.

5. Possible target J.Clim or JGR Description of global SSU/MSU/AMSU behavior Lower stratosphere: sondes vs. satellites Upper stratosphere: satellites vs. rockets/lidars Discussion of consistency with models based on existing model literature Aim for draft by Summer 2005