Exploring the Linkages among Mid-Latitude Dynamics, Clouds, and Climate Sensitivity

点击翻译按钮获取中文摘要

The goal of this research is to better understand the connection between mid-latitude clouds and dynamics in observations. The reasons for why the such linkages are well-represented in some global climate models but not in others will be studied. The implications of these processes on model climate sensitivity and future climate projections will also be examined. In the first part of the project, observed and model cloud radiative properties will be composited with respect to the centers of cyclones and anticyclones over the mid-latitude oceans of the Northern and Southern Hemispheres, to examine in the sectors of weather systems linked to model biases and uncertainties in future climate projections. In the second part of the project, idealized model experiments will be performed using two versions of the Community Atmosphere Model with very different representations of Southern Ocean cloud radiative properties. In both model versions, quadrupled carbon dioxide experiments will be run with the radiative properties of the clouds enabled and disabled, in order to explore the role of varying cloud-radiative effects in governing the response of the Southern Hemisphere mid-latitude jet to increased greenhouse gas forcing. By better understanding cloud-radiative-dynamical connections in observations and how they are misrepresented in models, the proposed project not only can improve theoretical knowledge of the role of clouds in the climate system, but also can provide additional constraints on cloud parameterizations that will help to reduce uncertainty in future model projections.