Atmosphere Ocean Science Colloquium

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Reducing uncertainties in climate predictions by constraining aerosols and clouds

Speaker: Zhaoyi Shen, Caltech

Location: Online

Date: Thursday, February 3, 2022, 4 p.m.

Notes:

Earth’s climate is projected to continue to change over this century, but the magnitude is highly uncertain. Aerosols and clouds are among the largest sources of uncertainties. In this talk I will highlight some of my recent work aiming at better understanding aerosols and clouds. In the first half, I will talk about how historical land temperature records can be used to constrain aerosol radiative forcing. It is shown that aerosols play an important role in setting regional land temperature trends. The resulting emergent constraint suggests a strong global aerosol forcing, and implies a relatively high climate sensitivity. In the second half, I will talk about how to leverage the potential of high-resolution models to improve cloud parameterizations in global climate models. I will present a framework that allows high-resolution simulations to be run anywhere on the globe, in any climate state, driven by output from climate models. The setup is used to create a library of high-resolution simulations of clouds across different cloud regimes, which substantially expands the dataset available for the evaluation and calibration of climate models. I will conclude by discussing briefly some of my current and future work on reducing the uncertainties in climate projection in a systematic manner.