Constraining Clouds and Convective Parameterizations in a Climate Model Using Paleoclimate Data

Abstract

Cloud and convective processes vary at scales significantly smaller than a general circulation model (GCM) grid box, requiring them to be parameterized on simulated grid-scale variables (Boucher et al., 2013). Because such parameterizations employ different assumptions (Lopez, 2007), representation of cloud and convective effects in climate models inherently hold large uncertainties. Cloud and convective parameterizations, aside from aerosol schemes and aerosol-cloud interactions (Meehl et al., 2020), are considered the leading source of inter-model spread in equilibrium climate sensitivity (ECS) estimates (

Increasingly Sophisticated Climate Models Need the Out‐Of‐Sample Tests Paleoclimates Provide

“…While there is no direct proxy for clouds, they exert a dominant control on large‐scale sea surface temperature (SST) patterns (e.g., Burls & Fedorov, 2014 ; Erfani & Burls, 2019 ; Fedorov et al., 2015 ) and model differences in meridional energy transport (Donohoe & Battisti, 2012 ; Stone, 1978 ). Perturbed parameter ensembles in which uncertain cloud and convective parameters are perturbed in different climates (e.g., Ramos et al., 2022 ; Sagoo et al., 2013 ) can be used to determine the best suite of parameters and/or geographical locations with high surface temperature sensitivity to these parameters. Quantifying uncertainty in these parameters is critical for constraining ECS.…”

What Controls the Mesoscale Variations in Water Isotopic Composition Within Tropical Cyclones and Squall Lines? Cloud Resolving Model Simulations in Radiative‐Convective Equilibrium

“…Similarly, the depletion observed in Texan speleothems has been interpreted as enhanced activity of large, long‐lived, organized convective systems (Maupin et al., 2021). In addition to paleoclimate applications, better understanding how convective processes impact the water isotopic composition is also relevant to assess the added value of water isotopic measurements to better quantify convective processes and better evaluate their representation in models (Bony et al., 2008; Diekmann et al., 2021; Field et al., 2014; Ramos et al., 2022).…”

Process‐Based Intercomparison of Water Isotope‐Enabled Models and Reanalysis Nudging Effects

“…These endeavors could be further enhanced by considering factors such as soil moisture (Zhou et al, 2021), plants (Beyer et al, 2020), surface water (Marković et al, 2020), and anthropogenic combustion-derived vapor (Xing et al, 2020). Also, water isotope simulations play a practical role in improving model performance by aiding in the determination of physics-related parameters for cloud and convection processes (Ramos et al, 2022). In this regard, the proposition put forth by the US Climate Variability and Predictability Program (CLIVAR) report (Bailey et al, 2021), as well as the perspective shared by S. G. Dee et al (2023), underscores the significant benefits of incorporating water isotope physics into the physics of Intergovernmental Panel on Climate Change (IPCC)-class GCMs.…”

“…Also, water isotope simulations play a practical role in improving model performance by aiding in the determination of physics‐related parameters for cloud and convection processes (Ramos et al., 2022). In this regard, the proposition put forth by the US Climate Variability and Predictability Program (CLIVAR) report (Bailey et al., 2021), as well as the perspective shared by S. G. Dee et al.…”