|
The Unified Model is a Numerical Weather Prediction〔(Use of the Unified model for weather forecasting at the Met Office ) The Met Office 2011. Retrieved 10 November 2011.〕 and climate modeling〔(Use of the Unified model for climate modeling at the Met Office ) The Met Office 2011. Retrieved 10 November 2011.〕 software suite originally developed by the United Kingdom Met Office, and now both used and further developed by many weather-forecasting agencies around the world.〔(The Unified Model Collaboration ). The Met Office 2010. Retrieved 22 April 2010.〕 The Unified Model gets its name because a single model is used across a range of both timescales (nowcasting to centennial) and spatial scales (convective scale to climate system earth modelling).〔(The Unified Model ). The Met Office 2011. Retrieved 10 November 2011.〕 The models are grid-point based, rather than wave based, and are run on a variety of supercomputers around the world. The Unified Model atmosphere can be coupled to a number of ocean models.〔(Met Office ocean models ) The Met Office 2011. Retrieved 10 November 2011.〕 At the Met Office it is used for the main suite of Global Model, North Atlantic and Europe model (NAE) and a high-resolution UK model (UKV), in addition to a variety of Crisis Area Models and other models that can be run on demand. Similar Unified Model suites with global and regional domains are used by many other national or military weather agencies around the world for operational forecasting. Data for numerical weather prediction is provided by observations from satellites, from the ground (both human and from automatic weather stations), from buoys at sea, radar, radiosonde weather balloons, wind profilers, commercial aircraft and a background field from previous model runs. The computer model is only adjusted towards the observations using assimilation, rather than forcing the model to accept an observed value that might make the system unstable (and could be an inaccurate observation).〔(Met Office data assimilation and ensembles ). Retrieved 28 December 2009.〕 The Unified Model software suite is written in Fortran (originally 77 but now predominantly 90)〔 〕 and uses height as the vertical variable. Because most developments of interest are at near to the ground the vertical layers are closer together near the surface. ==Principal UM suites at the Met Office== The Met Office runs a range of Numerical Weather Prediction suites using the UM.〔(Met Office Unified Model ). Met Office 2009. Retrieved 28 December 2009.〕 All of the models use varying resolutions of topography with greater accuracy at higher resolutions. The limiting factor with all models is that for a weather event to be recorded by the model it must be at least three grid points in size. Thus for the global model at 40 km, a weather system must be at least 120 km to be modelled. This means smaller phenomena such as small depressions, smaller hurricanes and large thunderstorms are too small for the model to catch them. As the resolution increases smaller events can be caught, the 1.5 km model for example, is reputedly capable of modelling individual showers. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Unified Model」の詳細全文を読む スポンサード リンク
|