Skip to content

GFDL Research Highlights

April 5th, 2022 - S2S Prediction in GFDL SPEAR: MJO Diversity and Teleconnections

Prediction on weather and seasonal timescales has become routine, but the “subseasonal” time scale of a few weeks has proven difficult. The Madden-Julian oscillation (MJO), a large complex of tropical thunderstorms, is the dominant subseasonal phenomenon over the tropics, and its prediction is critical for subseasonal prediction of tropical cyclones, atmospheric rivers, and other extreme events. Read More…

March 28th, 2022 - Tripling of Western U.S. Particulate Pollution from Wildfires in a Warming Climate

Record-setting fires in the western US over the last decade caused severe air pollution, loss of human life, and property damage. Enhanced drought and increased biomass in a warmer climate may fuel larger and more frequent wildfires in the coming decades. The air quality impact of increased wildfires in a warming climate has often been overlooked in current model projections, owing to the lack of interactive fire emissions of gases and particles responding to climate change in Earth System Model (ESM) projection simulations. Read More…

March 18th, 2022 - Oceanic and Atmospheric Drivers of Post-El-Niño Chlorophyll Rebound in the Equatorial Pacific

In the tropical Pacific, year-to-year changes in chlorophyll, a proxy for the phytoplankton base of ocean food webs, is dominated by the El Niño–Southern Oscillation. El Niño, triggered by westerly wind anomalies and subsequent redistributions of upper ocean heat content, can sharply reduce the regional supply of nutrients, limiting phytoplankton growth. GFDL’s new Earth System Model (ESM4.1) captures not only the onset and extent of chlorophyll anomalies during El Niño events, but also a pronounced post-El Niño “chlorophyll rebound” that produces positive equatorial Pacific chlorophyll anomalies in the summer following El Niño events. Read More…

March 16th, 2022 - Global coastal ecosystem responses to a half-century increase in river nitrogen loads

Coastal oceans host diverse ecosystems and serve as important habitats for marine fish species. Over the past century, anthropogenic activities have resulted in substantial climatic and land use changes that stress coastal environments, often leading to eutrophication, harmful algal blooms, and deoxygenation. Rivers are a primary source of eutrophication, supplying an increasing amount of anthropogenic nitrogen to the coastal ocean over the past century. Read More…

August 23rd, 2021 - The Alaskan summer 2019 extreme heat event: the role of anthropogenic forcing, and projections of the increasing risk of occurrence

An extreme heat event, breaking all previous records, occurred over southwestern Alaska in the summer of 2019. Extreme heat can have significant societal and economic effects, including damaging roads and infrastructure, displacing marine ecosystems, and increasing wildfire risk, with disproportionate costs to Alaska’s rural and indigenous communities. The authors examined the extent to which human-driven climate change played a role in increasing the likelihood of experiencing such an extreme event. Read More…

July 28th, 2021 - Anthropogenic forcing and response yield observed positive trend in Earth’s energy imbalance

The observed trend in Earth’s energy imbalance, a measure of the acceleration of heat uptake by the planet, is a fundamental indicator of perturbations to climate. The study found that it is exceptionally unlikely (< 1% probability) that this observed trend can be explained by natural variations in the climate system alone. Using climate model simulations and by conducting a hierarchy of GFDL CM4/AM4 experiments, the authors estimated the anthropogenic and internal variability contributions to the observed trend during 2001-2020. The study concludes that the satellite record provides clear evidence of a human-influenced climate system. Read More…

June 16th, 2021 - Horizontal circulation across density surfaces contributes substantially to the long-term mean northern Atlantic Meridional Overturning Circulation

The Atlantic Meridional Overturning Circulation (AMOC) has profound impacts on many aspects of climate, including temperature and precipitation. How and why the AMOC changes remains a challenging issue. The Greenland Sea is often viewed as the northern terminus of the AMOC and it has been suggested that the shutdown of open-ocean deep convection in the Labrador or Greenland Seas would substantially weaken the AMOC. This study suggests that the Arctic Ocean, not the Greenland Sea, is the northern terminus of the mean AMOC. Open-ocean deep convection, in either the Labrador or Greenland Seas, contributes minimally to the mean AMOC, hence it may not be weakened substantially by a shutdown of open-ocean deep convection. Meanwhile, horizontal circulation contributes more than 40% to the maximum mean northeastern subpolar AMOC. Read More…

March 30th, 2021 - Climate change is probably increasing the intensity of tropical cyclones

This ScienceBrief presents a summary of the state of the science on tropical cyclones (tropical storms, hurricanes, and typhoons) and climate change. The authors assessed more than 90 peer-reviewed scientific articles, with a focus on articles describing observations of, or projected future changes to, the frequency and intensity of tropical cyclones (TCs) globally or in key regions, as well as changes in tropical cyclone-related rainfall and storm surge. Read More…

rss_feedGFDL Research Highlights RSS Feed