June 6th, 2019 - Uncertainties in Tropical-Cyclone Translation Speed
A recent study found a downward trend from 1949-2016 in the speed at which tropical cyclones move. If this could be attributed to climate change the implications would be enormous. Slower moving storms, as exemplified by Hurricane Harvey in 2017, have the potential to produce much more rainfall than faster ones. Read More…
June 4th, 2019 - Advancements in Hurricane Prediction With NOAA’s Next‐Generation Forecast System
When using European Centre for Medium‐Range Weather Forecasts (ECMWF) initial conditions, a new global weather model built at NOAA’s Geophysical Fluid Dynamics Laboratory produces better hurricane forecast skill than the world‐leading European model. Read More…
The Atlantic Multidecadal Variability (AMV) has profound climate impacts. Improvement of our understanding of the AMV mechanisms is crucial for successful future prediction of AMV and associated climate impacts, with enormous social and economic implications. Read More…
Dynamical seasonal prediction systems have recently shown great promises in predicting tropical cyclone activity. GFDL’s Forecast–oriented Low Ocean Resolution (FLOR) model (Vecchi et al. 2014) provides experimental predictions to National Centers for Environmental Prediction (NCEP) each month as part of the North American Multi-Model Ensemble (NMME) project. The current study analyzes this state-of-the-art prediction system and offers a robust assessment of when and where the seasonal prediction of tropical cyclone activity is skillful. Read More…
April 26th, 2019 - Prominence of the tropics in the recent rise of global nitrogen pollution
In this study, GFDL’s Land Model (LM3-TAN) was used to analyze the past two and half centuries of land nitrogen storage, fluxes, and pollution to the ocean and atmosphere, considering not only the effect of increased anthropogenic reactive nitrogen (e.g., synthetic fertilizers and atmospheric deposition associated with agricultural industrialization and fossil fuel combustion) inputs, but also the effects of elevated atmospheric CO2, land use and land cover change, and climate change. The results show that globally, land has served as a net nitrogen sink since the late 1940s, buffering coastal waters against eutrophication and society against greenhouse gas-induced warming. Read More…
Prediction of convective-scale storms, such as severe thunderstorms or tornadoes, has been traditionally performed with limited-area models. Issues related to the limited extent of the domain and the external boundary conditions remain significant challenges, so a global convection-permitting model without side boundaries is potentially more advantageous for mesoscale prediction. However, present-day computing resources are insufficient to support real-time global convective-scale weather prediction. Read More…
In parts of many estuaries and other coastal areas, such as the Chesapeake Bay, the concentration of oxygen dissolved in the water regularly drops to a value so low that many species of fish, crabs, and other ecologically and economically important creatures are unable to live. This condition, known as hypoxia, is often driven by warm temperatures and other climate conditions. Subseasonal to seasonal scale forecasting models, including those developed by GFDL, have shown skill at forecasting variations in temperature and other drivers of hypoxia up to several months in advance. Translating these forecasts into skillful forecasts of hypoxia could enable improved management of fisheries, reduce fishing effort, and allow more adaptive management of water quality. Read More…
Observations show that Arctic sea ice is rapidly declining, but observations also clearly show an expansion of Southern Ocean (SO) sea ice extent during the satellite era (1979 to the present). This modest increase is consistent with an observed SO cooling trend. The sea surface temperature (SST) and sea ice concentration (SIC) trends are not homogeneous in space, with opposing signs in the Amundsen-Bellingshausen Seas versus the Ross and Weddell Seas. Read More…
November 19th, 2018 - Change in future climate due to Antarctic ice melt
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…