Remote Sensing Of Boundary Layer And Aerosol Over Nanjing By Lidar

Atmospheric aerosol can impact the radiative budget of earth-atmosphere system by absorption and scattering solar radiation. On the other hand, they can act as cloud condensation nuclei to affect the formation, lifetime and optical properties of cloud. Therefore, aerosols have been a research hotspot on atmospheric research society. MPL(Micro pulse Lidar), as an advanced active remote sensing instrument, has higher spatial and temporal resolution and can monitor aerosol, cloud and planetary boundary layer long-timely and continuously. This paper studied the aerosol and planetary boundary layer over Nanjing based on the data of MPL, MODIS, Sonde and Hysplit data from2010/10to2011/11. The main conclusions are as follows:1, In order to quantitatively retrieve the aerosol extinction coefficient from MPL, this paper calibrated the system parameter, analyzed the correction of raw signal and LR (extinction and backscattering ratio) over Nanjing combing with MODIS data. The seasonal variation of LR is following smaller order, summer (63sr), spring (48sr), autumn (45sr) and winter (40sr).2, By using the wavelet method we analyzed the seasonal and daily variation of boundary layer height, then discussed the influence of meteorological condition on boundary layer height. We found a significantly positive relationship between the PBL development and the surface temperature and a significantly negative relationship with the surface relative humidity; Clouds can reduce the maximum mixing layer height effectively and reduce the time to get to the maximum mixing layer height.3, The majority of aerosol particles are located below3km, and the maximum extinction coefficients were found near the surface and gradually decreased with height. The seasonal variation of near-ground extinction coefficient is following smaller order, winter, autumn, summer and spring. However, the far-ground extinction coefficient seasonal variation is in another order as summer, spring, autumn and winter.4, Aerosol vertical distribution and optical thickness has obvious diurnal variation. Vertical distribution of aerosols in the stable boundary layer was gradually decreasing trend from low to high and uniformly mixed when boundary layer is unstable. The diurnal variation of the optical thickness is divided into two types, morning and evening high in the summer and winter, low noon.; compared to the morning and evening low in the spring and autumn, high noon.