A new collection of single model initial-condition large ensembles (SMILEs) can test statistical assumptions with a cleaner separation between sources of uncertainty in climate projections. In particular, the potential bias at regional scales or for variables with a lot of internal variability can be greatly reduced.
Yin and coauthors use the new GFDL CM4 and CM4HR models to consider a series of climate change experiments under the CMIP6 protocol to study characteristics of extreme sea level events and their future evolution in a fully coupled weather, climate, sea level, and storm surge modeling system. They found that even in the absence of global warming, the Gulf Coast is most vulnerable to hurricane-induced storm surge.
Zou and coauthors analyzed the transport and property fields across the Labrador Sea using OSNAP observations and an ocean reanalysis dataset GloSea5 to study why recent observations revealed minimal contribution of the Labrador Sea convection to the subpolar AMOC strength. They found that the density compensation has important consequences on the strength of the overturning circulation.
Internal variability and anthropogenic forcing have contributed to the widening of the tropical belt during the last several decades. To better understand the effect of individual anthropogenic drivers (including aerosols) on the tropical belt, Zhao, Allen, and coauthors utilize idealized simulations with very large single forcing perturbations in comprehensive coupled ocean-atmosphere models from the PDRMIP.
Zelinka and coauthors compared ECS values derived from CO2 quadrupling experiments conducted with CMIP6 and CMIP5 models and found that the latest models warm more than their predecessors by about 0.5˚C. The primary culprit for the enhanced warming was shown to be clouds.
A recent study explored sea surface temperature anomaly forecasts from an ensemble of eight global climate prediction systems contributing to NMME and found that predictability of warm temperature anomalies off the US West Coast was conditional on which process was driving the temperature anomalies in different phases of the heatwave.
A recent study uses large ensembles of an idealized general circulation model to demonstrate how episodic surface warming in the Arctic can lead to delayed responses in the stratosphere that persist for about two months, even in the absence of stationary waves.
Under exclusive CO2 forcing, climate models predicted twice as much Hadley cell expansion in the Southern Hemisphere as in the Northern Hemisphere. The finding was robust across models and all seasons except boreal fall.
A new version 3 of the NOAA-CIRES-DOE 20th Century Reanalysis (20CRv3) recreates a 180-year history of temperature, precipitation, winds, humidity, and many other variables from below the land surface to the top of the atmosphere.
A Bayesian network inference model was developed to account for and predict the likelihood of floods of various durations using physics informed predictors.
Funding for US CLIVAR provided by
