Effects of orbital decay on satellite-derived lower-tropospheric temperature trends

Abstract

The 17-year lower-tropospheric temperature record derived from the satellite Microwave Sounding Unit (MSU)1,2,3 shows a global cooling trend, from 1979 to 1995, of −0.05 K per decade at an altitude of about 3.5 km (refs 4, 5). Air temperatures measured at the Earth's surface, in contrast, have risen by approximately +0.13 K per decade over the same period4,6. The two temperature records are derived from measurements of different physical parameters, and thus are not directly comparable. In fact, the lower stratosphere is cooling substantially (by about −0.5 K per decade)5, so the warming trend seen at the surface is expected to diminish with altitude and change into a cooling trend at some point in the troposphere. Even so, it has been suggested that the cooling trend seen in the satellite data is excessive4,7,8. The difficulty in reconciling the information from these different sources has sparked a debate in the climate community about possible instrumental problems and the existence of global warming4,7,9. Here we identify an artificial cooling trend in the satellite-derived temperature series caused by previously neglected orbital-decay effects. We find a new, corrected estimate of +0.07 K per decade for the MSU-based temperature trend, which is in closer agreement with surface temperatures. We also find that the reported7 cooling of the lower troposphere, relative to the middle troposphere, is another artefact caused by uncorrected orbital-decay effects.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Cumulative orbital decays for NOAA satellites from 1979 to 1996.
Figure 2: Effect of correction for orbital decay on MSU2R lower-tropospheric temperature anomalies.

References

  1. 1

    Spencer, R. W. & Christy, J. R. Precise monitoring of global temperature trends from satellites. Science 247, 1558–1562 (1990).

    ADS  CAS  Article  Google Scholar 

  2. 2

    Spencer, R. W. & Christy, J. R. Precision and radiosonde validation of satellite gridpoint temperature anomalies. Part II: A tropospheric retrieval and trends during 1979–90. J. Clim. 5, 858–866 (1992).

    ADS  Article  Google Scholar 

  3. 3

    Christy, J. R. & McNider, R. T. Satellite greenhouse signal. Nature 367, 325 (1994).

    ADS  Article  Google Scholar 

  4. 4

    Hurrell, J. W. & Trenberth, K. E. Difficulties in obtaining reliable temperature trends: Reconciling the surface and satellite MSU2R trends. J. Clim.(in the press).

  5. 5

    Houghton, J. T. et al. (eds) Climate Change 1995: The Science of Climate Change (Cambridge Univ. Press, (1996)).

    Google Scholar 

  6. 6

    Jones, P. D. Recent warming in global temperature series. Geophys. Res. Lett. 21, 1149–1152 (1994).

    ADS  Article  Google Scholar 

  7. 7

    Hurrell, J. W. & Trenberth, K. E. Spurious trends in satellite MSU temperatures from merging different satellite records. Nature 386, 164–167 (1997).

    ADS  CAS  Article  Google Scholar 

  8. 8

    Hansen, J. et al. Satellite and surface temperature data at odds? Clim. Change 30, 103–117 (1995).

    ADS  Article  Google Scholar 

  9. 9

    Christy, J. R., Spencer, R. W. & Braswell, W. D. How accurate are satellite ‘thermometers’? Nature 389, 342–342 (1997).

    ADS  CAS  Article  Google Scholar 

  10. 10

    Hansen, J. et al. Forcings and chaos in interannual to decadal climate change. J. Geophys. Res. 102, 25679–25720 (1997).

    ADS  CAS  Article  Google Scholar 

  11. 11

    Willson, R. C. Total solar irradiance trend during solar cycles 21 and 22. Science 277, 1963–1965 (1997).

    ADS  CAS  Article  Google Scholar 

  12. 12

    Wentz, F. J. Awell-calibrated ocean algorithm for special sensor microwave/imager. J. Geophys. Res. 102, 8703–8718 (1997).

    ADS  Article  Google Scholar 

  13. 13

    Liebe, H. J. An updated model for millimeter wave propagation in moist air. Radio Sci. 20, 1069–1089 (1985).

    ADS  Article  Google Scholar 

  14. 14

    Gaffen, D. Temporal inhomogeneities in radiosonde temperature records. J. Geophys. Res. 99, 3667–3676 (1994).

    ADS  Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Frank J. Wentz.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Wentz, F., Schabel, M. Effects of orbital decay on satellite-derived lower-tropospheric temperature trends. Nature 394, 661–664 (1998). https://doi.org/10.1038/29267

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.