Computational geophysics is the field of study that uses any type of numerical computations to generate and analyze models of complex geophysical systems. It can be considered an extension, or sub-field, of both computational physics and geophysics. In recent years, computational power, data availability, and modelling capabilities have all improved exponentially, making computational geophysics a more populated discipline. [1] Due to the large computational size of many geophysical problems, high-performance computing can be required to handle analysis. [2] Modeling applications of computational geophysics include atmospheric modelling, oceanic modelling, general circulation models, and geological modelling. In addition to modelling, some problems in remote sensing fall within the scope of computational geophysics such as tomography, inverse problems, and 3D reconstruction.
The generation of geophysical models are a key component of computational geophysics. Geophysical models are defined as "physical-mathematical descriptions of temporal and/or spatial changes in important geological variables, as derived from accepted laws, theories, and empirical relationships." [3] Geophysical models are frequently used by researchers in all disciplines of environmental science.
In climate science, atmospheric, oceanic, and general circulation models are a crucial standby for researchers. Although remote sensing has been steadily providing more and more in-situ measurements of geophysical variables, nothing comes close to the temporal and geospatial resolution of data provided by models. Although data can be subject to accuracy issues due to the extrapolation techniques used, the usage of modeled data is a commonly accepted practice in climate and meteorological sciences. Oftentimes, these models will be used in concert with in-situ measurements.
A few well-known models are
Geological system models are frequently used in research, but have less public data availability than climatic and meteorological models. There is a wide range of software available that allows for geomodelling.
The United States Geological Survey (USGS) defines remote sensing as the measurement of some property by transmitting some type of radiation at a distance, and measuring the emitted and reflected radiation. Remote sensing can involve satellites, cameras, and sound wave emission. [7] Remote sensing is inherently a type of indirect measurement, meaning that some type of computation must be completed in order to obtain a measurement of the property of interest. For some applications, these computations can be highly complex. In addition, the analysis of these data products can be classified as computational geophysics.
In Canada, computational geophysics is offered as a university major in the form of a BSc (Hon.) with co-op at Carleton University. [8]
Elsewhere, Rice University has a Center for Computational Geophysics, [9] while Princeton University, [10] the University of Texas, [1] and California Institute of Technology [11] have similar research centers. Experts, laboratories, projects, internships, undergraduate programs, graduate programs and/or facilities in the program exist at the University of Queensland, Wyoming University, Boston University, Stanford University, Uppsala University, Kansas State University, Kingston University, Australian National University, University of California, San Diego, University of Washington, Nanyang Technological University, ETH Zurich, University of Sydney, Appalachian State University, University of Minnesota, University of Tasmania, Bahria University, Boise State University, University of Michigan, University of Oulu, University of Utah, and others.
Federal organizations that study or apply computational geophysics include
Numerical climate models are mathematical models that can simulate the interactions of important drivers of climate. These drivers are the atmosphere, oceans, land surface and ice. Scientists use climate models to study the dynamics of the climate system and to make projections of future climate and of climate change. Climate models can also be qualitative models and contain narratives, largely descriptive, of possible futures.
Geophysics is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. Geophysicists, who usually study geophysics, physics, or one of the Earth sciences at the graduate level, complete investigations across a wide range of scientific disciplines. The term geophysics classically refers to solid earth applications: Earth's shape; its gravitational, magnetic fields, and electromagnetic fields ; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. However, modern geophysics organizations and pure scientists use a broader definition that includes the water cycle including snow and ice; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere and solar-terrestrial physics; and analogous problems associated with the Moon and other planets.
The Rapid Update Cycle (RUC) was an American atmospheric prediction system that consisted primarily of a numerical forecast model and an analysis system to initialize the model. The first operational implementation was created in 1994, with 60km resolution and a 3-hour cycle.
A sudden stratospheric warming (SSW) is an event in which polar stratospheric temperatures rise by several tens of kelvins over the course of a few days. The warming is preceded by a slowing then reversal of the westerly winds in the stratospheric polar vortex. SSWs occur about six times per decade in the northern hemisphere, and about once every 20-30 years in the southern hemisphere. Only two southern SSWs have been observed.
A general circulation model (GCM) is a type of climate model. It employs a mathematical model of the general circulation of a planetary atmosphere or ocean. It uses the Navier–Stokes equations on a rotating sphere with thermodynamic terms for various energy sources. These equations are the basis for computer programs used to simulate the Earth's atmosphere or oceans. Atmospheric and oceanic GCMs are key components along with sea ice and land-surface components.
The ECMWF reanalysis project is a meteorological reanalysis project carried out by the European Centre for Medium-Range Weather Forecasts (ECMWF). The first reanalysis product, ERA-15, generated reanalyses for approximately 15 years, from December 1978 to February 1994. The second product, ERA-40 begins in 1957 and covers 45 years to 2002. As a precursor to a revised extended reanalysis product to replace ERA-40, ECMWF released ERA-Interim, which covers the period from 1979 to 2019. A new reanalysis product ERA5 has more recently been released by ECMWF as part of Copernicus Climate Change Services. This product has higher spatial resolution and covers the period from 1979 to present. Extension up to 1940 became available in 2023.
In atmospheric science, an atmospheric model is a mathematical model constructed around the full set of primitive, dynamical equations which govern atmospheric motions. It can supplement these equations with parameterizations for turbulent diffusion, radiation, moist processes, heat exchange, soil, vegetation, surface water, the kinematic effects of terrain, and convection. Most atmospheric models are numerical, i.e. they discretize equations of motion. They can predict microscale phenomena such as tornadoes and boundary layer eddies, sub-microscale turbulent flow over buildings, as well as synoptic and global flows. The horizontal domain of a model is either global, covering the entire Earth, or regional (limited-area), covering only part of the Earth. The different types of models run are thermotropic, barotropic, hydrostatic, and nonhydrostatic. Some of the model types make assumptions about the atmosphere which lengthens the time steps used and increases computational speed.
The Weather Research and Forecasting (WRF) Model is a numerical weather prediction (NWP) system designed to serve both atmospheric research and operational forecasting needs. NWP refers to the simulation and prediction of the atmosphere with a computer model, and WRF is a set of software for this. WRF features two dynamical (computational) cores, a data assimilation system, and a software architecture allowing for parallel computation and system extensibility. The model serves a wide range of meteorological applications across scales ranging from meters to thousands of kilometers.
The NCEP/NCAR Reanalysis is an atmospheric reanalysis produced by the National Centers for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR). It is a continually updated globally gridded data set that represents the state of the Earth's atmosphere, incorporating observations and numerical weather prediction (NWP) model output from 1948 to present.
Science On a Sphere (SOS) is a spherical projection system created by the United States National Oceanic and Atmospheric Administration (NOAA). It displays high-resolution video on a suspended globe with the aim of better representing global phenomena. Animated images of atmospheric storms, climate change, and ocean temperature can be displayed on the sphere to explain these complex environmental processes. SOS systems are most frequently installed in science museums, universities, zoos, and research institutions.
The Beaufort Gyre is one of the two major ocean currents in the Arctic Ocean. It is roughly located north of the Alaskan and Canadian coast. In the past, Arctic sea-ice would circulate in the Beaufort gyre up to several years, leading to the formation of very thick multi-year sea-ice. Due to warming temperatures in the Arctic, the gyre has lost an extensive amount of ice, practically turning what used to be a nursery for sea-ice to mature and grow into the thickest and oldest ice of the Arctic Ocean into a "graveyard" for older ice.
An atmospheric reanalysis is a meteorological and climate data assimilation project which aims to assimilate historical atmospheric observational data spanning an extended period, using a single consistent assimilation scheme throughout.
Eugenia Enriqueta Kalnay is an Argentine meteorologist and a Distinguished University Professor of Atmospheric and Oceanic Science, which is part of the University of Maryland College of Computer, Mathematical, and Natural Sciences at the University of Maryland, College Park in the United States.
James C. McWilliams is a professor at the UCLA Institute of Geophysics and Planetary Physics and Department of Atmospheric and Oceanic Sciences.
The NOAA National Operational Model Archive and Distribution System (NOMADS) is a Web-services based project providing both real-time and retrospective format independent access to climate and weather model data.
Masao Kanamitsu was a Japanese and American atmospheric scientist working in the field of data assimilation. His research greatly influenced global and regional climate change studies including development of breakthrough reanalysis and downscaling datasets and weather forecasting studies. He was the co-author of one of the most cited geophysics paper in his time.
Yellowstone was the inaugural supercomputer at the NCAR-Wyoming Supercomputing Center (NWSC) in Cheyenne, Wyoming. It was installed, tested, and readied for production in the summer of 2012. The Yellowstone supercomputing cluster was decommissioned on December 31, 2017, being replaced by its successor Cheyenne.
In March 2012, one of the greatest heat waves was observed in many regions of North America. Very warm air pushed northward west of the Great Lakes region, and subsequently spread eastward. The intense poleward air mass movement was propelled by an unusually intense low level southerly jet that stretched from Louisiana to western Wisconsin. Once this warm surge inundated the area, a remarkably prolonged period of record setting temperatures ensued.
The Cyclone Global Navigation Satellite System (CYGNSS) is a space-based system developed by the University of Michigan and Southwest Research Institute with the aim of improving hurricane forecasting by better understanding the interactions between the sea and the air near the core of a storm.
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.