@article{09ba98ed90d34ae8b8a9eb592c03c50f,
title = "Snow Reconciles Observed and Simulated Phase Partitioning and Increases Cloud Feedback",
abstract = "The surprising increase of Earth's climate sensitivity in the most recent coupled model intercomparison project (CMIP) models has been largely attributed to extratropical cloud feedback, which is thought to be driven by greater supercooled water in present-day cloud phase partitioning (CPP). Here, we report that accounting for precipitation in the Goddard Institute for Space Studies ModelE3 radiation scheme, neglected in more than 60% of CMIP6 and 90% of CMIP5 models, systematically changes its apparent CPP and substantially increases its cloud feedback, consistent with results using CMIP models. Including precipitation in the comparison with cloud–aerosol lidar and infrared pathfinder satellite observations (CALIPSO) measurements and in model radiation schemes is essential to faithfully constrain cloud amount and phase partitioning, and simulate cloud feedbacks. Our findings suggest that making radiation schemes precipitation-aware (missing in most CMIP6 models) should strengthen their positive cloud feedback and further increase their already high mean climate sensitivity.",
author = "Cesana, {Gr{\'e}gory V.} and Ackerman, {Andrew S.} and Fridlind, {Ann M.} and Israel Silber and Maxwell Kelley",
note = "Funding Information: GC and AA were partly supported by a CloudSat‐CALIPSO RTOP at the NASA Goddard Institute for Space Studies. IS and GC were supported by DOE grant DE‐SC0021004. GC was also supported by NOAA grant NA20OAR4310390. AA, AF and MK were supported by the NASA Modeling, Analysis, and Prediction Program. Contributions of IS and AF were also supported by DOE grant DE‐SC0018046. Resources supporting this work were provided by the NASA Center for Climate Simulation (NCCS) at Goddard Space Flight Center. We thank NASA for providing computing resources to run GISS ESM, NASA and CNES for giving access to CALIPSO observations, and Climserv for giving access to CALIPSO‐GOCCP observations and for providing computing resources to run COSP offline. We also acknowledge the World Climate Research Programme's Working Group on Coupled Modeling, which is responsible for CMIP, and thank the climate modeling groups for producing and making available their model output. We also thank Helene Chepfer and Jennifer Kay for useful discussions in generalizing the lidar simulator to include precipitation, Mike Bauer for his preliminary implementation of COSP in GISS‐ModelE3 and Mark Zelinka for making his radiative kernels and cloud feedback results publicly available. Finally, we thank Hui Su for editing the manuscript and Takuro Michibata, Yoko Tsushima and the anonymous reviewer for their helpful comments. Funding Information: GC and AA were partly supported by a CloudSat-CALIPSO RTOP at the NASA Goddard Institute for Space Studies. IS and GC were supported by DOE grant DE-SC0021004. GC was also supported by NOAA grant NA20OAR4310390. AA, AF and MK were supported by the NASA Modeling, Analysis, and Prediction Program. Contributions of IS and AF were also supported by DOE grant DE-SC0018046. Resources supporting this work were provided by the NASA Center for Climate Simulation (NCCS) at Goddard Space Flight Center. We thank NASA for providing computing resources to run GISS ESM, NASA and CNES for giving access to CALIPSO observations, and Climserv for giving access to CALIPSO-GOCCP observations and for providing computing resources to run COSP offline. We also acknowledge the World Climate Research Programme's Working Group on Coupled Modeling, which is responsible for CMIP, and thank the climate modeling groups for producing and making available their model output. We also thank Helene Chepfer and Jennifer Kay for useful discussions in generalizing the lidar simulator to include precipitation, Mike Bauer for his preliminary implementation of COSP in GISS-ModelE3 and Mark Zelinka for making his radiative kernels and cloud feedback results publicly available. Finally, we thank Hui Su for editing the manuscript and Takuro Michibata, Yoko Tsushima and the anonymous reviewer for their helpful comments. Publisher Copyright: {\textcopyright} 2021 American Geophysical Union. All Rights Reserved. This article has been contributed to by US Government employees and their work is in the public domain in the USA.",
year = "2021",
month = oct,
day = "28",
doi = "10.1029/2021GL094876",
language = "English (US)",
volume = "48",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "American Geophysical Union",
number = "20",
}