In the U.S., air pollution includes contributions from multiple local human and natural sources, as well as transported sources like wildfire smoke from Canada, dust plumes from Africa, and intercontinental pollution from Asia. Accurate projection of future climate and air quality at scales relevant to local and regional stakeholders requires a seamless modeling system that can provide detailed information over a targeted region, while still integrating the global Earth system components in a computationally efficient manner. Scientists at GFDL have developed a novel variable-resolution global chemistry-climate model, known as AM4VR, for research at the nexus of U.S. climate and air quality extremes. Read More…
GFDL Research Highlights
April 29th, 2024 - Poleward intensification of midlatitude extreme winds under warmer climate
Given the significant risks posed by near-surface extreme wind speeds associated with midlatitude cyclones to lives, livelihoods, and infrastructure, it is imperative to understand their physical changes, including magnitudes and patterns, under human-induced global climate change. This study used GFDL’s high-resolution (50 km grid-spacing) atmospheric climate model, AM4, to investigate the global impact of midlatitude cyclones on extreme wind speed events, in both hemispheres, under a warmer climate. The authors conducted simulations covering the period 1949–2019 for both the present-day climate and an idealised future global warming climate scenario with a sea surface temperature (SST) increase of 2 K. Read More…
Under global warming, changes in the location and structure of the deep convection in the tropics have profound consequences for tropical climate. The tropics are characterized by the ubiquitous presence of high ice clouds formed by detrainment from precipitating deep convection. The bulk of these clouds are so-called anvil clouds in extensive formations that shield the convective centers. These can persist for several hours after the decay of active convection and they carry low to moderate ice loads. Read More…
March 12th, 2024 - Atmospheric rivers over eastern US affected by Pacific/North America pattern
There is a growing awareness that atmospheric river (AR) activities are responsible for a wide range of environmental and socioeconomic impacts on the West coast of the U.S. The related heavy rainfall, snowfall, and associated floods, especially during winter, have been a focus of many previous studies. This research investigates the impact of AR on the Eastern U.S. (EUS). Read More…
The interplay between the ocean and atmosphere plays a crucial role in shaping weather patterns and temperatures around the world. Yet, the winter upper troposphere/lower stratosphere (UTLS) temperature/vertical motion response over the extratropical North Pacific induced by North Atlantic changes is not well understood. Using GFDL’s high-resolution climate model CM2.5, the authors corrected the North Atlantic Ocean circulation biases to unravel the wintertime atmospheric impacts. Read More…
February 8th, 2024 - Ocean biogeochemical fingerprints of fast-sinking tunicate and fish detritus
Marine ecosystems play a critical role in the global carbon cycle through the food web regulation of air-sea carbon fluxes and the transfer of particulate matter from the upper oceans to depth. Recent evidence has suggested that the detritus from fishes and gelatinous zooplankton, specifically the pelagic tunicates such as salps and pyrosomes, may have a disproportionate impact on the ocean’s biological pump due to them sinking approximately ten times faster than bulk detritus. These fluxes result in increased sequestration of particulate carbon and nutrients into the deep oceans, but their impact on biogeochemical cycles at depth is poorly understood. Read More…
Projections of future nutrient limitation and primary production have implications for fisheries management. The authors used GFDL’s Earth system model, ESM4.1, to explore climate-driven changes in the deposition of dust and iron from the atmosphere to the ocean under a range of climate change scenarios, in an attempt to understand where the “fish food” is going to be and why. Read More…
Greenhouse gas emissions from human activities trap heat (radiative forcing) and cause global warming. This warming is amplified or diminished by feedbacks in the climate system. We had limited direct observations of global greenhouse gas forcing and feedbacks, despite the fact that they are the primary causes of climate change. While it has long been known that resolving the thermal spectrum at different wavelengths can help us to better separate the signals due to forcings and feedbacks, observing this has been elusive because of irregular, uncalibrated, or limited measurements. However, the Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua Satellite has recently provided such data (2003-2021). Read More…
The occurrence of exceptionally high sea levels can cause severe coastal flooding and inundation, threatening lives and infrastructure in the coastal regions. High sea level also alters the coastal environment, moving barrier islands and cutting channels through them, impacting forests and crops, inundating the coastline with salt water, and damaging habitats essential to support wildlife. Read More…
November 17th, 2023 - Anthropogenic forcing changes coastal tropical cyclone frequency
Anthropogenic activities have been affecting our climate since the industrial revolution. The effect of anthropogenic climate change on tropical cyclones (TCs) is of particular concern because of their catastrophic damage at landfall and their relatively frequent occurrence compared to other natural hazards. However, attributing a regionally observed change in tropical cyclone frequency (TCF) to anthropogenic climate change is notoriously challenging for two main reasons. First, climate internal variability can considerably modulate regional TC activities. Second, reliable TC observations are only available since the satellite era, and therefore, not long enough to separate the potential effect of anthropogenic climate change from climate internal variability. Read More…