A comparison of model‐simulated trends in stratospheric temperatures

• DOI: 10.1256/qj.02.186
• Publication Date: 2003-04-25T21:06:59Z
• Authors: K. P. Shine; M. S. Bourqui; P. M. de F. Forster; S. H. E. Hare; U. Langematz; P. Braesicke; V. Grewe; M. Ponater; C. Schnadt; C. A. Smith; J. D. Haigh; J. Austin; N. Butchart; D. T. Shindell; W. J. Randel; T. Nagashima; R. W. Portmann; S. Solomon; D. J. Seidel; J. Lanzante; S. Klein; V. Ramaswamy; M. D. Schwarzkopf
• Keywords: Mean radiant temperature

Abstract Estimates of annual‐mean stratospheric temperature trends over the past twenty years, from a wide variety models, are compared both with each other and observed cooling seen in trend analyses using radiosonde satellite observations. The modelled driven by changes ozone (either imposed observations or calculated model), carbon dioxide relatively well‐mixed greenhouse gases, water vapour. comparison shows that whilst models generally simulate similar patterns vertical profile annual‐and global‐mean trends, there is significant divergence size even when trace gas perturbations imposed. Coupled‐chemistry as good agreement despite extra degree freedom coupled possess. annual‐ upper stratosphere (near 1 hPa) dominated changes, reasonable At about 5 hPa, mean systematically greater than data; however, for some depending on due to vapour uncertainty estimates model just overlap. Near 10 hPa In lower (20–70 hPa), appears be dominant contributor cooling, although it does not, its own, seem explain entire cooling. Annual‐ zonal‐mean at 100 50 also examined. depletion alone all latitudes. midlatitudes northern hemisphere significantly exceeds alone. There an indication effect high latitudes, but variability precludes firm conclusion. discrepancies between reduced if effects increased concentration included, could largely removed certain assumptions were made regarding distribution increase. However, given uncertainties geographical extent stratosphere, time period which such have been sustained, reasons discrepancy cannot ruled out. Copyright © 2003 Royal Meteorological Society