Cloud feedback is a type of climate change feedback that has been difficult to quantify in contemporary climate models. It can affect the magnitude of internally generated climate variability or they can affect the magnitude of climate change resulting from external radiative forcings. Cloud representations vary among global climate models, and small changes in cloud cover have a large impact on the climate.
The Community Climate System Model (CCSM) is a coupled general circulation model (GCM) developed by the University Corporation for Atmospheric Research (UCAR) with funding from the National Science Foundation (NSF), the Department of Energy (DoE), and the National Aeronautics and Space Administration (NASA). The coupled components include an atmospheric model, a land-surface model, an ocean model, and a sea ice model. CCSM is maintained by the National Center for Atmospheric Research (NCAR).
A circumpolar vortex, or simply polar vortex, is a large region of cold, rotating air; polar vortices encircle both of Earth's polar regions. Polar vortices also exist on other rotating, low-obliquity planetary bodies. The term polar vortex can be used to describe two distinct phenomena; the stratospheric polar vortex, and the tropospheric polar vortex. The stratospheric and tropospheric polar vortices both rotate in the direction of the Earth's spin, but they are distinct phenomena that have different sizes, structures, seasonal cycles, and impacts on weather.
Jonathan Michael Gregory is a climate modeller working on mechanisms of global and large-scale change in climate and sea level on multidecadal and longer timescales at the Met Office and the University of Reading.
Geophysical Fluid Dynamics Laboratory Coupled Model is a coupled atmosphere–ocean general circulation model (AOGCM) developed at the NOAA Geophysical Fluid Dynamics Laboratory in the United States. It is one of the leading climate models used in the Fourth Assessment Report of the IPCC, along with models developed at the Max Planck Institute for Climate Research, the Hadley Centre and the National Center for Atmospheric Research.
Thomas R. Knutson is a climate modeller at the US Geophysical Fluid Dynamics Laboratory, a division of the National Oceanic and Atmospheric Administration (NOAA). His research covers hurricane activity, the link between climate change and hurricane incidence and intensity, and climate change detection and attribution.
Polar amplification is the phenomenon that any change in the net radiation balance tends to produce a larger change in temperature near the poles than in the planetary average. This is commonly referred to as the ratio of polar warming to tropical warming. On a planet with an atmosphere that can restrict emission of longwave radiation to space, surface temperatures will be warmer than a simple planetary equilibrium temperature calculation would predict. Where the atmosphere or an extensive ocean is able to transport heat polewards, the poles will be warmer and equatorial regions cooler than their local net radiation balances would predict. The poles will experience the most cooling when the global-mean temperature is lower relative to a reference climate; alternatively, the poles will experience the greatest warming when the global-mean temperature is higher.
The Arctic dipole anomaly is a pressure pattern characterized by high pressure on the arctic regions of North America and low pressure on those of Eurasia. This pattern sometimes replaces the Arctic oscillation and the North Atlantic oscillation. It was observed for the first time in the first decade of 2000s and is perhaps linked to recent climate change. The Arctic dipole lets more southern winds into the Arctic Ocean resulting in more ice melting. The summer 2007 event played an important role in the record low sea ice extent which was recorded in September. The Arctic dipole has also been linked to changes in arctic circulation patterns that cause drier winters in Northern Europe, but much wetter winters in Southern Europe and colder winters in East Asia, Europe and the eastern half of North America.
Sea ice in the Arctic has declined in recent decades in area and volume due to climate change. It has been melting more in summer than it refreezes in winter. Global warming, caused by greenhouse gas forcing is responsible for the decline in Arctic sea ice. The decline of sea ice in the Arctic has been accelerating during the early twenty‐first century, with a decline rate of 4.7% per decade. It is also thought that summertime sea ice will cease to exist sometime during the 21st century.
Gabriele Clarissa Hegerl is a German climatologist. She is a professor of climate system science at the University of Edinburgh School of GeoSciences. Prior to 2007 she held research positions at Texas A&M University and at Duke University's Nicholas School of the Environment, during which time she was a co-ordinating lead author for the Intergovernmental Panel on Climate Change (IPCC) Fourth and Fifth Assessment Report.
CICE is a computer model that simulates the growth, melt and movement of sea ice. It has been integrated into many coupled climate system models as well as global ocean and weather forecasting models and is often used as a tool in Arctic and Southern Ocean research. CICE development began in the mid-1990s by the United States Department of Energy (DOE), and it is currently maintained and developed by a group of institutions in North America and Europe known as the CICE Consortium. Its widespread use in earth system science in part owes to the importance of sea ice in determining Earth's planetary albedo, the strength of the global thermohaline circulation in the world's oceans, and in providing surface boundary conditions for atmospheric circulation models, since sea ice occupies a significant proportion (4-6%) of earth's surface. CICE is a type of cryospheric model.
Beate Gertrud Liepert is a research scientist at Columbia University, as well as in North West Research Associates, Redmond and a lecturer at Seattle University. Her research focuses on climate variability: inter-annual changes, centennial time scales, the water and energy cycles.
Pacific Meridional Mode (PMM) is a climate mode in the North Pacific. In its positive state, it is characterized by the coupling of weaker trade winds in the northeast Pacific Ocean between Hawaii and Baja California with decreased evaporation over the ocean, thus increasing sea surface temperatures (SST); and the reverse during its negative state. This coupling develops during the winter months and spreads southwestward towards the equator and the central and western Pacific during spring, until it reaches the Intertropical Convergence Zone (ITCZ), which tends to shift north in response to a positive PMM.
Bette Otto-Bliesner is an earth scientist known for her modeling of Earth's past climate and its changes over different geological eras.
Marika Holland is a scientist at the National Center for Atmospheric Research known for her work on modeling sea ice and its role in the global climate.
Sukyoung Lee is a professor at Pennsylvania State University known for her research on circulation in Earth's atmosphere and the Southern Ocean. In 2021 Lee was elected a fellow of the American Geophysical Union.
Rong Zhang is a Chinese-American physicist and climate scientist at the National Oceanic and Atmospheric Administration. Her research considers the impact of Atlantic meridional overturning circulation on climate phenomena. She was elected Fellow of the American Meteorological Society in 2018 and appointed their Bernhard Haurwitz Memorial Lecturer in 2020.
Rebecca Woodgate is a professor at the University of Washington known for her work on ocean circulation in polar regions.
Thomas L. Delworth is an atmospheric and oceanic climate scientist and Senior Scientist at the Geophysical Fluid Dynamics Laboratory (GFDL), part of NOAA. He also serves on the faculty of Oceanic Science at Princeton University.
Ronald J. Stouffer is a meteorologist and adjunct professor at the University of Arizona, formerly Senior Research Climatologist and head of the Climate and Ecosystems Group at the Geophysical Fluid Dynamics Laboratory (GFDL), part of NOAA. He has also served on the faculty of Princeton University.
