The Simplified Exchange Approximation: A New Method for Radiative Transfer Calculations

“…Surface drag is formulated via a Richardson number-dependent Monin-Obukhov (1954) scheme, and vertical diffusion is treated by a first-order closure scheme with eddy diffusivity coefficients as functions of Richardson number (Nicolini and Saulo 1995). Radiation follows the Fels-Schwarzkopf (1975) algorithm and the diurnal cycle is fully considered except for variations of the sun's azimuthal angle. Moist convective parameterization is currently introduced using the cumulus cloud ensemble model developed by Arakawa and Schubert (1974).…”

Section: Data Models and Methodologymentioning

confidence: 99%

Error Evaluation of NCEP and LAHM Regional Model Daily Forecasts over Southern South America

Saulo¹,

Seluchi²,

Campetella³

et al. 2001

Wea. Forecasting

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NCEP short-range operational forecast and Limited Area HIBU (Federal Hydrometeorological Institute and Belgrade University) Model (LAHM) regional model performance during a 2-month period over the southern part of South America are evaluated through the analysis of bias and rmse's. While spatial structure of errors could be only examined using gridded operational analyses as the ''ground truth,'' observed data have been used at two radiosonde stations to have an independent control of forecast and analysis quality. LAHM precipitation forecast error has been also determined using observed 24-h accumulated precipitation over a subregion of interest.Bias and rmse are, in general, lower for Medium-Range Forecast Model (MRF) 24-h forecasts than for the regional model, though MRF errors appear to be larger than those reported by other studies carried out over the whole Southern Hemisphere, suggesting the necessity to perform regional verification analysis whenever gridded analyses and/or forecasts are being used. This recommendation particularly holds over data-void regions like South America.While geopotential and wind biases do not exhibit a particular pattern in either forecast, there is a clear tendency to cold biases over the whole troposphere, and for the MRF in particular, growing with height.The results obtained from LAHM evaluation suggest that continuous development is needed to keep this regional forecast system as a plausible counterpart of available global model products for fulfillment of local requirements.

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“…The convective precipitation scheme is of Betts and Miller (1986) modified by Janjic(1994). The shortwave and longwave radiation codes follow parameterizations of Lacis andHansen (1974) andFels andSchwartzkopf (1975), respectively. The land-surface scheme is of Chen et al (1997).…”

Section: A Short Description Of Ncep Eta Modelmentioning

confidence: 99%

Climate version of the ETA regional forecast model

Pisnichenko

Тарасова

2009

Theor Appl Climatol

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The regional climate model prepared from Eta WS (workstation) forecast model has been of the investigation of a consistency between the output fields of the Eta model and HadAM3P are presented. The geopotential, temperature and wind fields of both models were analysed.For the evaluation of the likeness of these two models outputs, there were used Fourier analysis of time series, consistency index, constituted from linear regression coefficients, time mean and space mean models' arithmetic difference and root mean square difference, dispersion analysis, and some others characteristics. This investigation demonstrates that there are not significant differences in behaviour and spatial arragement of large-scale structures of the two models.Also, the regional model characteristics do not have considerable positive or negative trend during integration time in relation to the global model characteristics. From the total analysis we can affirm that in the description of large-scale climate structures these two models are in consistency.

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The Simplified Exchange Approximation: A New Method for Radiative Transfer Calculations

Cited by 274 publications

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An evaluation of NCEP Eta model predictions of surface energy budget and cloud properties by comparison with measured ARM data

An evaluation of NCEP Eta model predictions of surface energy budget and cloud properties by comparison with measured ARM data

Error Evaluation of NCEP and LAHM Regional Model Daily Forecasts over Southern South America

Climate version of the ETA regional forecast model

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