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Thursday, May 17
Applications
Time Series Modeling
Thu, May 17, 5:15 PM - 6:15 PM
Lake Fairfax A
 

The Divergence Between Observed and Modeled Temperature Trends in the Tropical Troposphere 1958-2017 (304741)

*Ross McKitrick, University of Guelph 

Keywords: Tropical troposphere, model testing, trend estimation, HAC-robust, radiosonde

With the release of the 2017 radiosonde record there is now a 60-year homogenized series of temperature observations in the tropical lower- and mid-troposphere, where climate models project a rapid, globally maximal response to rising greenhouse gas levels. We compare trends in three radiosonde-based observational series (RICH, RAOBCORE and RATPAC) to 102 CMIP5 model simulations using a HAC-robust trend estimator allowing for a step change at a known point. Consistent with many prior studies we find models overpredict warming. Virtually all models warm too fast compared to observations, in most individual cases the differences are statistically significant and on average the hypothesis of equivalent trends between models and observations strongly rejects.