Ocean acidification (OA) is a consequence of the absorption of anthropogenic carbon emissions and it profoundly impacts marine life. Arctic regions are particularly vulnerable to rapid pH changes due to low ocean buffering capacities and high stratification. This research applied unsupervised machine learning methodology to simulations of surface Arctic acidification using two state-of-the-art coupled climate models. The authors identified four sub-regions whose boundaries are influenced by present-day and projected sea ice patterns. The regional boundaries are consistent between the models and across lower and higher carbon emissions scenarios. Read More…
GFDL Research Highlights
Potential future changes in the genesis frequency and distribution of tropical cyclones are important for society, yet uncertain. Confidence in model projections largely relies on whether we can physically explain why the models projected such changes. After analyzing climate simulations from multiple models, the authors find that future changes in the patterns and frequency of tropical cyclone genesis are largely governed by dynamic effects—that is, by human-induced changes in the atmospheric circulation. Read More…
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 US 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 25th, 2022 - Are multi-seasonal forecasts of atmospheric rivers possible?
In Western North America, 30% of the annual precipitation is determined by atmospheric rivers (ARs) that occur during less than 15% of the winter season. ARs are beneficial to water supply but can also produce extreme precipitation hazards when making landfall. Consequently, ARs exert significant socioeconomic impacts on this region. Read More…
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…
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…
There is intense public and scientific interest in weather and climate extremes. Understanding to what degree these phenomena are predictable has great practical value to society. Midlatitude baroclinic waves drive extratropical weather and climate extremes, but the predictability of these waves beyond 2 weeks has long been deemed low. Read More…
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…
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…