Global, Hemispheric, and Zonal Temperature Deviations Derived From Radiosonde Records

Graphics    Digital Data

Investigator

J. K. Angell
National Oceanic and Atmospheric Administration—Air Resources Laboratory (R/E/AR),
SSMC3, Station 3459,
1315 East West Highway,
Silver Spring, Maryland 20910, U.S.A.

DOI

10.3334/CDIAC/cli.005

Period of Record

1958-2008 (relative to a 1958-1977 average)

Special Note

Nine tropical radiosonde stations in this 63-station network were identified as anomalous in Angell et al. (2003). Upon removal of these 9 stations, the resulting 54-station network results in significant differences in many of the times series and their associated temperature trends. Full details are given in Angell et al. (2003), which will allow users to better judge the utility of the current 63-station-network time series. Please watch this space for the coming addition of corrected, 54-station time series. (4/30/2009)

Methods

Surface temperatures and thickness-derived temperatures from a 63-station, globally distributed radiosonde network have been used to estimate global, hemispheric, and zonal annual and seasonal temperature deviations. Most of the temperature values used were column-mean temperatures, obtained from the differences in height (thickness) between constant-pressure surfaces at individual radiosonde stations. The pressure-height data before 1980 were obtained from published values in Monthly Climatic Data for the World. Between 1980 and 1990, Angell used data from both the Climatic Data for the World and the Global Telecommunications System (GTS) Network received at the National Meteorological Center. Between 1990 and 1995, the data were obtained only from GTS, and since 1995 the data have been obtained from National Center for Atmospheric Research files. The data are evaluated as deviations from the mean based on the interval 1958-1977. The station deviations have been averaged (with equal weighting) to obtain annual and seasonal temperature deviations for the globe, the Northern and Southern Hemispheres, and the following latitudinal zones: North (60° N-90° N) and South (60° S-90° S) Polar; North (30° N-60° N) and South (30° S-60° S) Temperate; North (10° N-30° N) and South (10° S-30° S) Subtropical; Tropical(30° S-30° N); and Equatorial (10° S-10° N). The seasonal calculations are for the standard meteorological seasons (i.e., winter is defined as December, January, and February; spring is March, April, and May, etc.) and the annual calculations are for December through the following November (i.e., for the four meteorological seasons). For greater details, see Angell and Korshover (1983) and Angell (1988, 1991).

Trends

Based on data from Angell's global network of 63 radiosonde stations, over the period from 1958 through 2008, the global mean, near-surface air temperature warmed by approximately 0.18°C/decade, the 850-300 mb tropospheric layer warmed by about 0.08°C/decade, the 300-100 mb tropopause layer temperature cooled by approximately -0.23°C/decade (driven mainly by large changes in the Polar zones), and the 100-50 mb low-stratospheric layer cooled by about -0.60°C/decade. At the surface, 2007 was the warmest year in the 51-year record (0.97°C above the long-term mean), and 2002 was the second warmest year with a departure of 0.88°C.

References

• Angell, J.K. 1988. Variations and trends in tropospheric and stratospheric global temperatures, 1958-87. Journal of Climate 1:1296-1313.
• Angell, J.K. 1991. Changes in tropospheric and stratospheric global temperatures, 1958-88. pp. 231-47. In M.E. Schlesinger (ed.), Greenhouse-Gas-Induced Climatic Change: A Critical Appraisal of Simulations and Observations. Elsevier Science Publishers, Amsterdam, Netherlands.
• Angell, J.K., and J. Korshover. 1983. Global temperature variations in the troposphere and stratosphere, 1958-82. Monthly Weather Review 111:901-21.
• Angell, J.K. 2009. Effect of exclusion of anomalous tropical stations on temperature trends from a 63-Station radiosonde network, and comparison with other analyses. Journal of Climate 16:2288-2295, doi: 10.1175/2763.1.

4/2009