Observation And Simulation Study On Distribution Characteristics Of Radiation And Energy Balance Over Nanjing In Summer

With the development of urbanization, the radiation and energy budget over different urban and suburban underlying surface become increasingly different. To date, Many domestic and overseas scholars did urban energy budget experiments, but the experimental results were vastly different for different methods because of the different climatic conditions and different degrees of the development in urban. Based on the radiation, turbulence flux and fluctuation wind velocity observed using the eddy correlation method on the urban and suburban sites in Nanjing from27July to2August2010, the characteristics of the radiation and energy budget over different urban and suburban underlying surface on clear day in summer are analyzed and compared. In order to provide some fundamental characteristics of the radiation and energy budget over different urban and suburban underlying surface, the data observed by Eddy covariance (EC) observations was studied by using classical statistics. At the same time, using anthropogenic heat parameterization scheme of WRF mode, according to practical Anthropogenic heat of city, two simulation tests are analyzed. We are wondering if anthropogenic heat is Critical Parameters of radiation and energy balance of city in summer. The results show:(1) The radiation over urban and suburban was significantly different on clear day. The average of upward long-wave radiation were505.1W/m2and488.3W/m2and the average of upward short-wave radiation were24.6W/m2and39.5W/m2over urban and suburban, the result was coefficient of surface temperature and radiation trap.(2)The energy budget over urban and suburban was significantly different on clear day. Heat storage and sensible heat flux play major roles in urban energy budget. The sensible heat flux in urban is positive all day. The stratification of the atmosphere over urban is always unstable. In suburban, Latent heat flux plays major role in urban energy budget. The stratification of the atmosphere is stable in night.(3) The average of the diurnal albedo of the urban (33m above the tower) and suburban (2m over the grass in) were0.11and0.17. The urban albedo was representative characteristic of entirety urban levels of the hundreds-meters diameter. And the albedo of2m over the concrete surface was0.23in a forefathers’ investigation. It was representative characteristic of the concrete surface in urban. In addition, the suburban albedo showed more serious asymmetry than the urban. (4)The heat storage of urban and suburban were56%and7%of the net radiation flux in daytime. Compared with the heat storage of in forefathers’ investigations, the characteristic of the heat storage had close correlations with the proportion of hard ground in the observation site and the influence of approved anthropogenic heat.(5)Through two examples simulation and observed data, trend of simulated air temperature, radiation and energy balance is good. And the air temperature of two simulation examples is2and0.18degree smaller than the observation value. Relative error of the simulated long wave radiation is not more than2.1%in urban simulation, and Relative error of up-long wave is2%.(6) Two simulation examples itself by contrast, the simulated air temperature, energy balance of test2are bigger than testl data. Test2has greater impact on sensible heat flux increased by8.7W/m2and8.8W/m2in urban and suburban. At the same time Radiation balance of test2is closer to practical energy balance of city...