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Climate Forecast System (NCEP)
__NOTOC__ The Climate Forecast System or coupled forecast system (CFS) is a medium to long range numerical weather prediction and a climate model run by the National Centers for Environmental Prediction (NCEP) to bridge weather and climate timescales. Version 2 became operational as CFSv2 in 2011. Overview CFSv2 is run once daily at NCEP, at multiple time scales. The medium-range model forecasts in one-week intervals out to four weeks, while the longer-range scale forecasts on three-month moving averages out some nine months. The shorter scale has some overlap with the Global Forecast System, NAVGEM and FIM models (among several other medium-range models) that the US government runs for operational forecast purposes. "Coupled" refers to the fact that the model couples atmospheric An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numerical Weather Prediction
Numerical weather prediction (NWP) uses mathematical models of the atmosphere and oceans to weather forecasting, predict the weather based on current weather conditions. Though first attempted in the 1920s, it was not until the advent of computer simulation in the 1950s that numerical weather predictions produced realistic results. A number of global and regional forecast models are run in different countries worldwide, using current weather observations relayed from radiosondes, weather satellites and other observing systems as inputs. Mathematical models based on the same physical principles can be used to generate either short-term weather forecasts or longer-term climate predictions; the latter are widely applied for understanding and projecting climate change. The improvements made to regional models have allowed significant improvements in Tropical cyclone track forecasting, tropical cyclone track and air quality forecasts; however, atmospheric models perform poorly at han ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Model
Numerical climate models (or climate system 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 (i.e. not numerical) models and contain narratives, largely descriptive, of possible futures. Climate models take account of incoming energy from the Sun as well as outgoing energy from Earth. An imbalance results in a change in temperature. The incoming energy from the Sun is in the form of short wave electromagnetic radiation, chiefly visible and short-wave (near) infrared. The outgoing energy is in the form of long wave (far) infrared electromagnetic energy. These processes are part of the greenhouse effect. Climate models vary in complexity. For example, a simple radiant heat transfer model ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Centers For Environmental Prediction
The United States National Centers for Environmental Prediction (NCEP) delivers national and global weather, water, climate, and space weather guidance, forecasts, warnings, and analyses to government agencies and private users. The centers form part of the National Weather Service. NCEP consists of nine centers: # Aviation Weather Center provides aviation warnings and forecasts of hazardous flight conditions at all levels within domestic and international air space. # Climate Prediction Center monitors and forecasts short-term climate fluctuations and provides information on the effects climate patterns can have on the nation. # Environmental Modeling Center develops and improves numerical weather, climate, hydrological and ocean prediction through a broad program in partnership with the research community. # National Hurricane Center provides forecasts of the movement and strength of tropical weather systems and issues watches and warnings for the North Atlantic and the E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moving Average
In statistics, a moving average (rolling average or running average or moving mean or rolling mean) is a calculation to analyze data points by creating a series of averages of different selections of the full data set. Variations include: #Simple moving average, simple, #Cumulative moving average, cumulative, or #Weighted moving average, weighted forms. Mathematically, a moving average is a type of convolution. Thus in signal processing it is viewed as a low-pass filter, low-pass finite impulse response filter. Because the boxcar function outlines its filter coefficients, it is called a boxcar filter. It is sometimes followed by Downsampling (signal processing), downsampling. Given a series of numbers and a fixed subset size, the first element of the moving average is obtained by taking the average of the initial fixed subset of the number series. Then the subset is modified by "shifting forward"; that is, excluding the first number of the series and including the next value in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Forecast System
The Global Forecast System (GFS) is a global numerical weather prediction system containing a global computer model and variational analysis run by the United States' National Weather Service (NWS). Operation The mathematical model is run four times a day, and produces forecasts for up to 16 days in advance, but with decreased spatial resolution after 10 days. The forecast skill generally decreases with time (as with any numerical weather prediction model) and for longer term forecasts, only the larger scales retain significant accuracy. It is one of the predominant synoptic scale medium-range models in general use. Principles The GFS model has a finite volume cubed sphere (FV3) dynamical core with an approximate horizontal resolution of 28 km between grid points, which drops to 70 km between grid points for forecasts between one and two weeks. In the vertical, the model is divided into 127 layers and extends to the mesopause (roughly ~80 km). It produces forec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Navy Global Environmental Model
The Navy Global Environmental Model (NAVGEM) is a global numerical weather prediction computer simulation run by the United States Navy's Fleet Numerical Meteorology and Oceanography Center. This mathematical model is run four times a day and produces weather forecasts. Along with the NWS's Global Forecast System, which runs out to 16 days, the ECMWF's Integrated Forecast System (IFS) and the CMC's Global Environmental Multiscale Model (GEM), both of which run out 10 days, and the UK Met Office's Unified Model The Unified Model is a numerical weather prediction and climate modeling software suite originally developed by the United Kingdom Met Office from 1990 and now both used and further developed by many weather-forecasting agencies around the world. ..., which runs out to 7 days, it is one of five synoptic scale medium-range models in general use. The NAVGEM became operational in February 2013, replacing the NOGAPS. It uses the same forecast range as the NOGAPS did (t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flow-following, Finite-volume Icosahedral Model
The Flow-following, finite-volume Icosahedral Model (FIM) is an experimental numerical weather prediction model that was developed at the Earth System Research Laboratories in the United States from 2008 to 2016. The FIM was developed as a candidate to eventually supplant the Global Forecast System, the United States's current medium-range forecast model. The FIM was originally slated to become operational some time in 2014 but never did so. The model produces similar results to the GFS, but runs slower on the NWS's operational computers. Its three-part name derives from its key features: "flow-following" indicates that its vertical coordinates are based on both terrain and potential temperature (isentropic sigma coordinates, previously used in the now-discontinued rapid update cycle model), and "finite-volume" describes the method used for calculating horizontal transport. The "icosahedral" portion describes the model's most uncommon feature: whereas most grid-based forecast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Model
In atmospheric science, an atmospheric model is a mathematical model constructed around the full set of primitive equations, primitive, Dynamical systems theory, dynamical equations which govern atmospheric motions. It can supplement these equations with Parametrization (climate), parameterizations for Turbulence, turbulent diffusion, radiation, moist processes (clouds and precipitation (meteorology), precipitation), heat transfer, heat exchange, soil, vegetation, surface water, the Kinematics, 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 Eddy covariance, 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 other astronomical object, planetary body), or ''regional'' (''limited-area''), covering only part o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ensemble Forecasting
Ensemble forecasting is a method used in or within numerical weather prediction. Instead of making a single forecast of the most likely weather, a set (or ensemble) of forecasts is produced. This set of forecasts aims to give an indication of the range of possible future states of the atmosphere. Ensemble forecasting is a form of Monte Carlo analysis. The multiple simulations are conducted to account for the two usual sources of uncertainty in forecast models: (1) the errors introduced by the use of imperfect initial conditions, amplified by the chaotic nature of the equations of the atmosphere, which is often referred to as sensitive dependence on initial conditions; and (2) errors introduced because of imperfections in the model formulation, such as the approximate mathematical methods to solve the equations. Ideally, the verified future atmospheric state should fall within the predicted ensemble spread, and the amount of spread should be related to the uncertainty (error) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pascal (unit)
The pascal (symbol: Pa) is the unit of pressure in the International System of Units (SI). It is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is an SI coherent derived unit defined as one newton per square metre (N/m2). It is also equivalent to 10 barye (10 Ba) in the CGS system. Common multiple units of the pascal are the hectopascal (1 hPa = 100 Pa), which is equal to one millibar, and the kilopascal (1 kPa = 1000 Pa), which is equal to one centibar. The unit of measurement called '' standard atmosphere (atm)'' is defined as . Meteorological observations typically report atmospheric pressure in hectopascals per the recommendation of the World Meteorological Organization, thus a standard atmosphere (atm) or typical sea-level air pressure is about 1013 hPa. Reports in the United States typically use inches of mercury or millibars (hectopascals). In Cana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Community Earth System Model
The Community Earth System Model (CESM) is a fully coupled numerical simulation of the Earth system consisting of atmospheric, ocean, ice, land surface, carbon cycle, and other components. CESM includes a climate model providing state-of-art simulations of the Earth's past, present, and future. It is the successor of the Community Climate System Model (CCSM), specifically version 4 (CCSMv4), which provided the initial atmospheric component for CESM. Strong ensemble forecasting capabilities, CESM-LE (CESM-Large Ensemble), were developed at the onset to control for error and biases across different model runs (realizations). Simulations from the Earth's surface through the thermosphere are generated utilizing the Whole Atmosphere Community Climate Model (WACCM). CESM1 was released in 2010 with primary development by the Climate and Global Dynamics Division (CGD) of the National Center for Atmospheric Research (NCAR), and significant funding by the National Science Foundation T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
