Tuesday, June 28, 2011

New paper finds significant temperature response to the 11-year solar cycle

A paper published last week in the Journal of Geophysical Research examines long-term temperature trends over the past 30 years at three observation sites in the northern hemisphere and finds "significant temperature response to the 11 year solar cycle." The paper also finds a temperature cooling trend of the middle atmosphere over the period 1981-2009 at 2 of the 3 sites, and "near zero" change at the third. Meanwhile, the IPCC claims the 0.1% change in total solar irradiance over a typical solar cycle has no significant effect on temperature, while ignoring potential amplification by large changes in solar UV over solar cycles [which secondarily affects ozone production], potential secondary cloud effects, and a long term increase in solar activity over the past several millennia.



JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 116, D00P05, 11 PP., 2011
doi:10.1029/2010JD015275
Key Points
  • The temperature trend and solar cycle was studied with Rayleigh lidar data sets
  • The temperature cooling trend was found at TMF and OHP and was near zero at MLO
  • Positive response was found with negative response in winter stratosphere at OHP
Tao Li
School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China, State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing, China
Thierry Leblanc
Table Mountain Facility, Jet Propulsion Laboratory, California Institute of Technology, Wrightwood, California, USA
I. Stuart McDermid
Table Mountain Facility, Jet Propulsion Laboratory, California Institute of Technology, Wrightwood, California, USA
Philippe Keckhut
Laboratoire Atmosphères, Milieux, Observations Spatiales, Institut Pierre-Simon Laplace, Guyancourt, France
Alain Hauchecorne
Laboratoire Atmosphères, Milieux, Observations Spatiales, Institut Pierre-Simon Laplace, Guyancourt, France
Xiankang Dou
School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
The long-term temperature profile data sets obtained by Rayleigh lidars at three different northern latitudes within the Network for the Detection of Atmospheric Composition Change were used to derive the middle atmosphere temperature trend and response to the 11 year solar cycle. The lidars were located at the Mauna Loa Observatory, Hawaii (MLO, 19.5°N); the Table Mountain Facility, California (TMF, 34.4°N); and the Observatoire de Haute Provence, France (OHP, 43.9°N). A stratospheric cooling trend of 2–3 K/decade was found for both TMF and OHP, and a trend of ≤0.5 ± 0.5 K/decade was found at MLO. In the mesosphere, the trend at TMF (3–4 K/decade) was much larger than that at both OHP and MLO (<1 K/decade). The lidar trends agree well with earlier satellite and rocketsonde trends in the stratosphere, but a substantial discrepancy was found in the mesosphere. The cooling trend in the upper stratosphere at OHP during 1981–1994 (∼2–3 K/decade) was much larger than that during 1995–2009 (≤0.8 K/decade), coincident with the slightly increasing upper stratospheric ozone density after 1995. Significant temperature response to the 11 year solar cycle was found. The correlation was positive in both the stratosphere and mesosphere at MLO and TMF. At OHP a wintertime negative response in the upper stratosphere and a positive response in the middle mesosphere were observed during 1981–1994, but the opposite behavior was found during 1995–2009. This behavior may not be a direct solar cycle response at all but is likely related to an apparent response to decadal variability (e.g., volcanoes, modulated random occurrence of sudden stratospheric warmings) that is more complex.

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