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Title: The Mechanisms of Natural Variability and its Interaction with Anthropogenic Climate Change Final Report

The project had two main components. The first concerns estimating the climate sensitivity in the presence of forcing uncertainty and natural variability. Climate sensitivity is the increase in the average surface temperature for a given increase in greenhouse gases, for example a doubling of carbon dioxide. We have provided new, probabilistic estimates of climate sensitivity using a simple climate model an the observed warming in the 20th century, in conjunction with ideas in data assimilation and parameter estimation developed in the engineering community. The estimates combine the uncertainty in the anthropogenic aerosols with the uncertainty arising because of natural variability. The second component concerns how the atmospheric circulation itself might change with anthropogenic global warming. We have shown that GCMs robustly predict an increase in the length scale of eddies, and we have also explored the dynamical mechanisms whereby there might be a shift in the latitude of the jet stream associated with anthropogenic warming. Such shifts in the jet might cause large changes in regional climate, potentially larger than the globally-averaged signal itself. We have also shown that the tropopause robustly increases in height with global warming, and that the Hadley Cell expands, and that the expansion of themore » Hadley Cell is correlated with the polewards movement of the mid-latitude jet.« less
  1. Princeton Univ., NJ (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
Final Report: DOE-Princeton-SC0005189
DOE Contract Number:
Resource Type:
Technical Report
Research Org:
Princeton Univ., NJ (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
58 GEOSCIENCES; 97 MATHEMATICS AND COMPUTING; Anthropogenic Climate Change; Natural Variability; Climate Sensitivity