Effect Of Solar Radiation Simulation Based On The Different Initial Field And Radiation Parameterization Scheme

In order to improve the solar radiation modeling and forecasting effect, global, diffuse and direct radiation were simulated by WRF-SES2radiation model system in Beijing urban area and suburb area based on ECMWF and NCEP reanalysis data in Jan., Apr., Jul., and Oct.,2010. First of all, we put emphasis on effect differences of solar radiation simulation based on two kinds of reanalysis data and impacts of differences of total cloud amount in initial fields on radiation simulation. The second place, we used WRF radiation parameterization combinations to assess the effect of solar radiation simulation. The preliminary conclusions are as follows:(1) Simulated values of global radiation in most of times in the above four months on the Beijing Observatory are greater than the observed values, those of scattered radiation are smaller than observed values, simulation values of total cloud amount are greater than the observed values; Simulated errors of radiation based on EC data in most of periods less than those based on NCEP data, this may be related for cloud simulation error that based on EC data is smaller;(2) Simulation effects of global radiation in Jan., and Apr. are better, those in Oct. take second place, those in Jul. are worse. Namely relative errors in Jan., and Apr. are smaller. Simulated errors of global radiation based on EC data in most of periods in Jul. are less than those based on NCEP data. Simulation errors based on two kinds of data in the other three months are close. Accuracy of global radiation simulation is largely affected by simulation effects of total cloud amount. Simulation effects of direct radiation are better in Jan., followed by those in Apr. and Oct. and results in Jul. are worse. Except for Apr., simulated errors of direct radiation based on EC data in most of periods in the other three months are less than those based on NCEP data; Simulation effects of scattered radiation are better in Jan. and Oct., followed by those in Apr. and Jul. Simulation errors of scattered radiation based on EC data in most of periods in Jan., Apr., Jul., and Oct. are less than those based on NCEP data;(3) Simulation errors based on two kinds of data are close in Jan.. Simulated errors of global radiation based on EC data in Apr., Jul., and Oct. are less than those based on NCEP data on the SDZ (Shang Dianzi regional atmospheric background station). Simulation errors of total cloud amount based on EC data are less than those based on NCEP data in the four months on the SDZ.(4) Simulation accuracy of global, direct and diffuse radiation using EC and NCEP data were obviously affected by simulation effects of cloud amounts in initial fields. When simulation errors of total cloud amount are small, simulation effects of global radiation are relatively good.(5) Simulated errors of global radiation and direct radiation on the Beijing Observatory and SDZ based on EC1(RRTM LW and Dudhia SW) are less than those based on EC2(RRTM LW and RRTMG SW), those of scattered radiation on EC2are smaller than those on EC1, simulation values of total cloud amount are greater on EC1than the observed values on EC2in the four months;(6) Simulated errors of global radiation direct radiation and scattered radiation on the Beijing Observatory and SDZ based on ECl and EC2are close in sunny days, those in cloud and rain days are different; Simulated errors of global radiation and direct radiation on the Beijing Observatory and SDZ based on EC1are less than those based on EC2, those of scattered radiation on EC2are smaller than those on EC1in cloud and rain days;(7) Simulated errors of total cloud amount on the Beijing Observatory and SDZ based on EC1and EC2are close in sunny days, those in cloud and rain days are different; Simulated errors of total cloud amount on the Beijing Observatory and SDZ based on EC1are less than those based on EC2;(8) Simulated errors of global radiation direct radiation and scattered radiation on the Beijing Observatory and SDZ based on EC1and EC2are close in sunny days, those in cloud and rain days are different; Simulated errors of global radiation and direct radiation on the Beijing Observatory and SDZ based on EC1are less than those based on EC2, those of scattered radiation on EC2are smaller than those on EC1in cloud and rain days, the reason of those was that:Total cloud amount simulated are effected by the different of WRF radiation parameterization schemes.