Ice sheet melt is a known neglected forcing in climate model simulations, contributing to uncertainties in climate projections. This is the first study to directly implement estimates of Antarctic ice sheet melt in a climate simulation, showing the actual change in climate projections due to the freshwater input. The authors used a large ensemble to confidently separate the freshwater signal from natural variability and show when we can expect these freshwater-induced effects to become significant. Read More…
The 2017 hurricane season in the North Atlantic Ocean was highly active, with six major hurricanes (MH). Three storms made landfall (Hurricanes Harvey, Irma, and Maria) – causing widespread damage over the Gulf Coast and the Caribbean. A number of factors might be linked to this enhanced MH activity in 2017, including moderate La Niña conditions in the Pacific. Read More…
Oceanic heat uptake (OHU) is a significant source of uncertainty in both the transient and equilibrium response to increasing the planetary radiative forcing. OHU differs among climate models and is related in part to their representation of vertical and lateral mixing. Read More…
The Tropical Cyclones (TCs) that form over the Gulf of Mexico have a high probability of making landfall at the surrounding coastal regions, causing severe property damage and loss of life. Skillful sub-seasonal prediction of TC activity is critical for early preparation and reducing damage in this region. Read More…
The Atlantic Meridional Overturning Circulation (AMOC) has profound impacts on various climate phenomena. Using both observations and simulations from multiple models of the Coupled Model Intercomparison Project, the authors estimated the amplitude of low-frequency AMOC variability in observations, compared it with those in model simulations, and examined the effects of low-frequency AMOC variability on the linkage between AMOC and Atlantic multidecadal variability (AMV). Read More…
Precipitation is characterized by substantial natural variability, including on regional and decadal scales. This relatively large variability poses a grand challenge in assessing the significance of anthropogenically forced precipitation changes. The authors use multiple large ensembles of climate change experiments to evaluate whether, on regional scales, anthropogenic changes in decadal precipitation mean state (i.e., ensemble average) are distinguishable – i.e., outside the range expected from natural variability. Read More…
There has been an increasing call for better seasonal precipitation prediction systems to support water resource management, particularly over regions like the western United States, where a multi-year drought persisted from 2012-2016. This research addresses the challenge of building a better prediction system by exploring the extent to which this past winter’s western U.S. precipitation anomalies may have been predictable, using experimental retrospective forecasts with GFDL’s Forecast-Oriented Low Resolution (FLOR) model. Read More…
Observed Atlantic major hurricane frequency has exhibited pronounced multidecadal variability since the 1940s. However, the cause of this variability is debated. This study explores the causes of the recent decline of Atlantic major hurricane frequency over the period 2005-2015, using various observational datasets and modeling results from a 500-year control simulation of a fully coupled earth system model, GFDL’s ESM2G. Read More…
The majority of annual precipitation in the Western United States accumulates between October and April, falling as snow in the mountains. As a result, snow accumulation forms mountain snowpack, peaking in early spring and melting into the summer, dominating runoff and influencing lower elevation streamflow. Variations in snowpack influence warm season water supply, wildfire risk, ecology, and industries like agriculture dependent on snow and downstream water availability. Read More…
Aerosol radiative forcing and its uncertainty are seen as major challenges that climate models face in reproducing observed temperature records. Climate models, such as those reporting results for the Fourth and Fifth Assessment Reports of the Intergovernmental Panel on Climate Change, exhibit a persistently large range of aerosol radiative forcing, both natural and anthropogenic. For this research, the authors carried out a systematic evaluation of the impact of radiative errors on simulated aerosol radiative effect across the diversity of aerosol distributions resulting from the same experiment, to address a persistent ambiguity in climate sensitivity. Read More…
