Human influence on the atmospheric vertical temperature structure: Detection and observations

Science

Volumn 274, Issue 5290, 1996, Pages 1170-1173

  Tett, Simon F B ^a   Mitchell, John F B ^a   Parker, David E ^a   Allen, Myles R ^b  

^a MET OFFICE   (United Kingdom)

^b RUTHERFORD APPLETON LABORATORY   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

OZONE;

AEROSOL; AIR QUALITY; ARTICLE; ATMOSPHERE; CLIMATE; GREENHOUSE EFFECT; OZONE LAYER; PRIORITY JOURNAL; SEA; TEMPERATURE SENSITIVITY;

AIR TEMPERATURE; ANTHROPOGENIC EFFECT; CLIMATE VARIATION; COUPLED ATMOSPHERE/OCEAN MODEL; RADIOSONDE; TEMPERATURE STRUCTURE;

EID: 0029661007     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.274.5290.1170     Document Type: Article

References (33)

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11. 3 data set is a seasonal climatology constructed from the zonai-mean climatology endorsed by the Commission internationale pour la Recherche Atmospherique (26) above 20 hPa and zonal-mean Solar Backscattered Ultraviolet satellite data for 1979 through 1981 (27) below 20 hPa.
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14. The radiosonde data set is based on operationally received monthly averages, data from publications, data requested from national sources, and, for the South Pole, from the Comprehensive Aerological Reference Data Set (29). Data are for standard levels (850, 700, 500, 300, 200, 150, 100, and 50 hPa). Gross error and hydrostatic checks were applied (30). Comparisons with colocated Microwave Sounding Unit data since 1979 were used to assess and remove biases associated with recent instrumental changes at radiosonde stations operated by Australia and at some New Zealand stations. This reduced the cooling at 50 hPa since 1980 by about 2°C at some stations, with a noticeable impact on the Southern Hemisphere subtropical zonal average changes. The station data were gridded on a 5° latitude by 10° longitude grid as monthly anomalies (with respect to 1971 through 1990). Missing gridboxes were filled with the average of the anomalies in neighboring gridboxes, if at least three of these, out of a maximum of eight, had data. Unlike (31), no spatial interpolation was done. We converted the "filled" gridded data set to zonal monthly mean anomalies for each 10° latitude band at each pressure level by averaging with the requirement that there be at least 4 out of 36 longitude points present. If this was not the case, then for that latitude the zonal mean value was set to missing data. We converted the monthly average zonal mean anomalies to annual mean anomalies by averaging the 12 monthly values. At each latitude-pressure point, there must be at least 8 months with data; otherwise, the point was set to missing data in the annual mean.
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16. 2.
17. j is the pressure.
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21. Segments of zonal mean atmospheric temperature 35 years long were taken from the control integration. The start year of each segment was offset from the start year of the previous segment by 5 years giving a total of 129 segments. For each segment, means for years 1 to 20 (corresponding to 1961 through 1980 of the observations and forced simulations) and for years 26 to 35 (corresponding to 1986 through 1995 of the observations and forced simulations) were computed and differenced.
22. The R and g statistics computed between the control and forced signals have an estimated 70 to 80 degrees of freedom (32). Thus, a conservative estimate of the significance level of statistics greater than the maximum control value is 2%.
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25. 1 will reduce the correlation to less than 1. We correct with a Fisher z transformation (24), translating the transformed PDFs such that their average values are equal to the transformed values obtained with the unperturbed signals. Results in Table 2 are then computed directly from these transformed PDFs. We believe that the bias correction gives the most accurate risk estimates. Use of it does not affect our key result that SENS1 is, on balance, in best agreement with the observations.
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33. 3 data set, using data provided by K. Shine. M. Gordon, D. Cullum, and M. O'Donnell carried out much of the processing required to produce the radiosonde data set. The work was partially supported by the U.K. Department of the Environment under contract PECD 7/12/37 (S.F.B.T., J.F.B.M., D.E.P., and computer time) and the U.K. Natural Environment Research Council and Wolfson College, Oxford (M.R.A.).