Comparison of Atmospheric Boundary Layer Height Retrieved from Radiosonde and Groundbased Microwave Radiometer Measurements

Abstract

As an important parameter that characterizes the structure of Atmospheric boundary layer (ABL), the boundary layer height (BLH) determines the degree of turbulent diffusion and exchange of heat and momentum within ABL. In this paper, synchronized observations of ground-based microwave radiometer (MWR) and radiosonde in Beijing Southern Meteorological Observatory from April 2017 to March 2018 are obtained to estimate BLH, based on the multiple linear regression algorithm and bulk Richardson number method, respectively. The BLHs derived from the two observations are compared and the temporal variation of BLH in Beijing are finally analyzed. Main conclusions are as follows: 1) the BLH retrieved by MWR is higher than that obtained by radiosonde by 157 m on average. The average deviation of BLH between MWR and radiosonde is smaller at 08 Beijing time (BJT) and 20 BJT than at 14 BJT, and the deviation is relatively smaller in spring and summer than other seasons. 2) BLH at 08 BJT is generally lower than that at 14 BJT and 20 BJT from both MWR and radiosonde observations. 3) radiosonde-obtained BLH peaks in the May while MWR-retrieved BLH reaches maximum in January and February. 4) BLH in Beijing at night is relatively low, which reaches the minimum $(\sim 622\mathrm {m}$ on average) around 05 BJT or 06 BJT. BLH gradually increases after 08 BJT and reaches the maximum $( \sim 908\mathrm {m}$ on average) around 15 BJT.