The Atmospheric Boundary Layer Height Study Based On Ground-based Remote Sensing And Numerical Simulation

The atmospheric boundary layer height (ABLH) directly impacts the dispersion of pollutants in urban area. It is an important parameter to predict pollution. The rapid development of Ground-based remote sensing is important to urban atmospheric boundary layer detection. The dissertation uses the observation of microwave radiometer, lidar and radiosonde to analysis the atmospheric boundary layer development of typical cities in the Yangtze River Delta. The main conclusions are as follows.(1). The atmospheric boundary layer height is determined from microwave radiometer with the parcel method (Parcel) and temperature gradient method (TGRAD). There are reasonable daily evolution of ABLHs determined by the two methods, the TGRAD estimated ABLHs mostly depend on the selection of threshold, the ABLHs with the Parcel method are higher than the results of the TGRAD, the largest difference between the two methods occurs in the well mixed boundary layer.(2). Based on lidar, a two-dimensional wavelet method (W2D) is proposed, the W2D estimated ABLHs are not sensitive to the selection of wavelet function; ABLHs extracted with wavelet method (WH), standard deviation method (STD) and the W2D have good consistency, the ABLHs with the W2D are consistent with results of the WH in summer and are close to the STD results in winter; the change trends of the ABLHs are consistent when the W2D and the Parcel are used. The ABLHs determined with the W2D are greater than ones of Parcel; Compared to the W2D results, the higher ABLHs are estimated from radiosonde.(3). Using the lidar observations in Shanghai in 2012 and 2013, the characteristics of the ABLHs in 2013 are investigated, the annual average ABLH of Shanghai is 1000m around, and the ABLHs are higher in the summer and autumn. Lidar observations in Suzhou in 2011 are analyzed, and results show higher average and maximum ABLH in spring than in winter. The peaks of ABLH in Suzhou are observed at about 16:00, the atmospheric boundary layer in the afternoon becomes relatively stable, and the atmospheric boundary layer in Suzhou dissipates later than Shanghai. The lidar signal come to be stronger during pollution than sunny days, the haze can influence the development of the atmospheric boundary layer.(4). The atmospheric boundary layer evolutions over Suzhou are simulated with WRF employing two different atmospheric boundary layer parameterization schemes (MYJ and YSU). The ABLHs simulated with MYJ and YSU are lower than those of microwave radiometer, the ABLHs of MYJ are relatively close to observations, but the ABLHs of YSU have a good agreement with microwave radiometer results. Anthropogenic heat (AH) has a significant effect on the dissipation of atmospheric boundary layer in afternoon. The simulated potential temperature near surface increases and relative humidity simulation of lower atmosphere layer decreases once the AH is introduced.