A51C-0050
Parameteric dependence of climate sensitivity and cloud response in CAM5 with a higher-order closure scheme
Friday, 18 December 2015
Poster Hall (Moscone South)
Minghuai Wang1, Zhun Guo2, Yun Qian3, Tianjun Zhou2 and Steven Ghan3, (1)Nanjing University, Nanjing, China, (2)Institute of Atmospheric Physics, Beijing, China, (3)Pacific Northwest National Laboratory, Richland, WA, United States
Abstract:
The parametric dependence of the climate sensitivity and cloud response in CAM5 with a higher-order closure cloud scheme CLUBB is examined by comparing control simulations and simulations with global sea surface temperature (SST) warmer by 4 K. CLUBB provides a unified treatment of boundary layer turbulence, cloud macrophysics, and shallow convection. 512 pairs of experiments were performed. A Quasi-Monte Carlo (QMC) sampling approach was adopted to effectively sample 18 selected parameters, including 14 parameters of CLUBB and 4 parameters of the Zhang-McFarlane deep convection scheme. A generalized linear model was further applied to study the response of simulated climate sensitivity to tunable parameters. Our results indicate large spread in climate sensitivity and key parameters and processes that contribute to the spread are identified. Observations are further used to constrain climate sensitivity.
