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Climate Forecast System
__NOTOC__ The Climate Forecast System or coupled forecast system (both names abbreviated 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 to oceanic modeling. Its forecasts are derived from a 16-member ensemble, with each member initialized on a lead of several days of conditions. The CFSv2 offers output that can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numerical Weather Prediction
Numerical weather prediction (NWP) uses mathematical models of the atmosphere and oceans to 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 for significant improvements in tropical cyclone track and air quality forecasts; however, atmospheric models perform poorly at handling processes that occur in a relatively const ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Model
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 (i.e. not numerical) models and also narratives, largely descriptive, of possible futures. Quantitative climate models take account of incoming energy from the sun as short wave electromagnetic radiation, chiefly visible and short-wave (near) infrared, as well as outgoing long wave (far) infrared electromagnetic. An imbalance results in a change in temperature. Quantitative models vary in complexity. For example, a simple radiant heat transfer model treats the earth as a single point and averages outgoing energy. This can be expanded vertically (radiative-convective models) and/or horizontally. Coupled atmosphere–ocean–sea ice global climate models ... [...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 its Partners and External User Communities. These products and services are based on a service-science legacy and respond to user needs to protect life and property, enhance that nation's economy and support the nation's growing need for environmental information. The centers form part of the National Weather Service. There are 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 progr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moving Average
In statistics, a moving average (rolling average or running average) is a calculation to analyze data points by creating a series of averages of different subsets of the full data set. It is also called a moving mean (MM) or rolling mean and is a type of finite impulse response filter. Variations include: simple, cumulative, or weighted forms (described below). 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 the subset. A moving average is commonly used with time series data to smooth out short-term fluctuations and highlight longer-term trends or cycles. The threshold between short-term and long-term depends on the application, and the parameters of the moving average will be set accordingly. It is also used in economics ... [...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 is a FV3 model with an approximate horizontal resolution of 13 km for the days 0-16 days. In the vertical, the model is divided into 127 layers and extends to the mesopause (roughly ~80 km), and temporally, it produces forecast output every hour for the first 120 hours, three hourly through day 10 and 12 hourly through day 16. The outp ... [...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, which runs out to 7 days, it is one of five synoptic scale The synoptic scale in meteorology (also known as large scale or cyclonic scale) is a horizontal length scale of the order of 1000 kilometers (about 620 miles) or more. This corresponds to a horizontal scale typical of mid-latitude depressions (e. ... 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 (thre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Model
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 ( clouds and precipitation), 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 ... [...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 method, 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 Chaos theory, chaotic nature of the evolution 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 Standard deviation, spread, and the amou ... [...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), and is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is defined as one newton per square metre and is equivalent to 10 barye (Ba) in the CGS system. The unit of measurement called standard atmosphere (atm) is defined as 101,325 Pa. 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. 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 Canada these reports are given in kilopascal ... [...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 (NSF) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
