Evaluation of retrieval methods for planetary boundary layer height based on radiosonde data
- 1State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing (LIESMARS), Wuhan University, Wuhan, China
- 2Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
- 3School of Electronic Information, Wuhan University
Abstract. Radiosonde (RS) is widely used to detect the vertical structures of the planetary boundary layer (PBL), and numerous methods have been proposed for retrieving PBL height (PBLH) from RS data. However, an algorithm that is suitable under all atmospheric conditions does not exist. This study evaluates the performance of four common PBLH algorithms under different thermodynamic stability conditions based on RS data collected from nine sites in January–December 2019. The four RS algorithms are the potential temperature gradient method (GMθ), relative humidity (RH) gradient method (GMRH), parcel method (PM) and Richardson number method (RM). Atmospheric conditions are divided into convective boundary layer (CBL), neutral boundary layer (NBL) and stable boundary layer (SBL) on the basis of the potential temperature profile. Results indicate that SBL is dominant at nighttime, whilst CBL dominates at daytime. Intercomparisons show that PBLH retrieved via RM is typically higher than those retrieved using the other methods under all and SBL conditions. PBLH retrieved using GMθ and GMRH is relatively low. PBLH from PM is the lowest under all and SBL classifications, and the highest under CBL and NBL classifications. Moreover, the uncertainty analysis shows that PBLH retrieved using different algorithms is consistent in most cases (more than 80 %) under CBL and NBL conditions. By contrast, the consistency of PBLH is less than 60 % under SBL condition. The average profiles and standard deviations of wind speed and potential temperature under consistent and inconsistent conditions indicate that consistent cases are typically accompanied by evident atmospheric stratification, such as a large gradient in the potential temperature profile or a low-level jet in the wind speed profile. These findings indicate that the reliability of the PBLH results retrieved from RS data is affected by the structure of the boundary layer. Overall, GMθ and RM are appropriate for CBL condition. GMθ and PM are recommended for NBL condition. GMθ and GMRH are robust for SBL condition. This comprehensive comparison provides a reference for selecting the appropriate algorithm when retrieving PBLH from RS data.
Hui Li et al.
Status: open (until 08 Jul 2021)
Hui Li et al.
Hui Li et al.
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