Cirrus is a genus of high cloud made of ice crystals. Cirrus clouds typically appear delicate and wispy with white strands. Cirrus are usually formed when warm, dry air rises, causing water vapor deposition onto rocky or metallic dust particles at high altitudes. Globally, they form anywhere between 4,000 and 20,000 meters above sea level, with the higher elevations usually in the tropics and the lower elevations in more polar regions.
Numerical climate models use quantitative methods to simulate the interactions of the important drivers of climate, including atmosphere, oceans, land surface and ice. They are used for a variety of purposes from study of the dynamics of the climate system to projections of future climate. Climate models may also be qualitative models and also narratives, largely descriptive, of possible futures.
Cloud albedo is a measure of the albedo or reflectivity of a cloud. Clouds regulate the amount of solar radiation absorbed by a planet and its solar surface irradiance. Generally, increased cloud cover correlates to a higher albedo and a lower absorption of solar energy. Cloud albedo strongly influences the Earth's energy budget, accounting for approximately half of Earth's albedo. Cloud albedo depends on the total mass of water, the size and shape of the droplets or particles and their distribution in space. Thick clouds reflect a large amount of incoming solar radiation, translating to a high albedo. Thin clouds tend to transmit more solar radiation and, therefore, have a low albedo. Changes in cloud albedo caused by variations in cloud properties have a significant effect on global climate.
Cloud feedback is the coupling between cloudiness and surface air temperature where a surface air temperature change leads to a change in clouds, which could then amplify or diminish the initial temperature perturbation. Cloud feedbacks can affect the magnitude of internally generated climate variability or they can affect the magnitude of climate change resulting from external radiative forcings.
Keith Peter Shine FRS is the Regius Professor of Meteorology and Climate Science at the University of Reading. He is the first holder of this post, which was awarded to the university by Queen Elizabeth II to mark her Diamond Jubilee.
Altostratus is a middle-altitude cloud genus made up of water droplets, ice crystals, or a mixture of the two. Altostratus clouds are formed when large masses of warm, moist air rise, causing water vapor to condense. Altostratus clouds are usually gray or blueish featureless sheets, although some variants have wavy or banded bases. The sun can be seen through thinner altostratus clouds, but thicker layers can be quite opaque.
Richard Siegmund Lindzen is an American atmospheric physicist known for his work in the dynamics of the middle atmosphere, atmospheric tides, and ozone photochemistry. He has published more than 200 scientific papers and books. From 1983 until his retirement in 2013, he was Alfred P. Sloan Professor of Meteorology at the Massachusetts Institute of Technology. He has disputed the scientific consensus on climate change and criticizes what he has called "climate alarmism."
Radiative forcing is the change in energy flux in the atmosphere caused by natural or anthropogenic factors of climate change as measured by watts / meter². It is a scientific concept used to quantify and compare the external drivers of change to Earth's energy balance. System feedbacks and internal variability are related concepts, encompassing other factors that also influence the direction and magnitude of imbalance.
Clouds and the Earth's Radiant Energy System (CERES) is on-going NASA climatological experiment from Earth orbit. The CERES are scientific satellite instruments, part of the NASA's Earth Observing System (EOS), designed to measure both solar-reflected and Earth-emitted radiation from the top of the atmosphere (TOA) to the Earth's surface. Cloud properties are determined using simultaneous measurements by other EOS instruments such as the Moderate Resolution Imaging Spectroradiometer (MODIS). Results from the CERES and other NASA missions, such as the Earth Radiation Budget Experiment (ERBE), could enable nearer to real-time tracking of Earth's energy imbalance and better understanding of the role of clouds in global climate change.
Earth's energy budget accounts for the balance between the energy that Earth receives from the Sun and the energy the Earth loses back into outer space. Smaller energy sources, such as Earth's internal heat, are taken into consideration, but make a tiny contribution compared to solar energy. The energy budget also accounts for how energy moves through the climate system. Because the Sun heats the equatorial tropics more than the polar regions, received solar irradiance is unevenly distributed. As the energy seeks equilibrium across the planet, it drives interactions in Earth's climate system, i.e., Earth's water, ice, atmosphere, rocky crust, and all living things. The result is Earth's climate.
Climate sensitivity is a measure of how much Earth's surface will cool or warm after a specified factor causes a change in its climate system, such as how much it will warm for a doubling in the atmospheric carbon dioxide concentration. In technical terms, climate sensitivity is the average change in global mean surface temperature in response to a radiative forcing, which drives a difference between Earth's incoming and outgoing energy. Climate sensitivity is a key measure in climate science, and a focus area for climate scientists, who want to understand the ultimate consequences of anthropogenic global warming.
CloudSat is a NASA Earth observation satellite, which was launched on a Delta II rocket on April 28, 2006. It uses radar to measure the altitude and properties of clouds, adding to information on the relationship between clouds and climate in order to help resolve questions about global warming.
Robert Donald Cess was a professor of atmospheric sciences at Stony Brook University. He was born in Portland, Oregon. Cess earned his bachelor of science degree in mechanical engineering from Oregon State University and his master's degree from Purdue University in Indiana in 1956. He received a Ph.D. from the University of Pittsburgh in 1959. He is a recognized leader in the fields of climate change and atmospheric radiation transfer. His research interests involve modeling of climate feedbacks that can either amplify or diminish global climate change, and interpreting surface and satellite remote sensing data.
The Jule G. Charney Award is the American Meteorological Society's award granted to "individuals in recognition of highly significant research or development achievement in the atmospheric or hydrologic sciences". The prize was originally known as the Second Half Century Award, and first awarded to mark to fiftieth anniversary of the society.
Amy C. Clement is an atmospheric and marine scientist studying and modeling global climate change at the University of Miami's Rosenstiel School of Marine and Atmospheric Science.
Tiffany Shaw is a geophysical scientist from Canada. She is currently an associate professor at the University of Chicago. She is known for her extensive contributions to the geophysical and atmospheric sciences.
Yolanda Shea is a Research Physical Scientist at NASA Langley Research Center in Hampton, Virginia. In 2019, Shea earned a Presidential Early Career Award for Scientists and Engineers (PECASE) for her work in pioneering shortwave spectral measurements.
Lin Chambers is an American physical scientist. She has developed and contributed to multiple international programs around science education and citizen science at NASA Langley Research Center.
Fixed anvil temperature hypothesis is a physical hypothesis that describes the response of cloud radiative properties to rising surface temperatures. It presumes that the temperature at which radiation is emitted by anvil clouds is constrained by radiative processes and thus does not change in response to surface warming. Since the amount of radiation emitted by clouds is a function of their temperature, it implies that it does not increase with surface warming and thus a warmer surface does not increase radiation emissions by cloud tops. The mechanism has been identified both in climate models and observations of cloud behaviour, it affects how much the world heats up for each extra tonne of greenhouse gas in the atmosphere. However, some evidence suggests that it may be more correctly formulated as decreased anvil warming rather than no anvil warming.
Kerry Harrison Cook is an American climate scientist who is a professor at the University of Texas at Austin. Her research focuses on the analysis of climate variability and change in the tropics using observational analysis and high-resolution numerical modeling. Specialties include the climate of Africa and the dynamics of intense tropical rainfall. She was elected Fellow of the American Meteorological Society in 2009 and was awarded the Joanne Simpson Tropical Meteorology Research Award in 2021. She is the Chair of the American Meteorological Society's Climate Variability and Change Committee.
