Abstract. The atmospheric boundary layer is an important atmospheric feature that
affects environmental health and weather forecasting. In this study, we
proposed a graphics algorithm for the derivation of atmospheric boundary
layer height (BLH) from the Cloud-Aerosol Lidar and Infrared Pathfinder
Satellite Observations (CALIPSO) data. Owing to the differences in scattering
intensity between molecular and aerosol particles, the total attenuated
backscatter coefficient 532 and attenuated backscatter coefficient 1064 were
used simultaneously for BLH detection. The proposed algorithm transformed the
gradient solution into graphics distribution solution to overcome the effects
of large noise and improve the horizontal resolution. This method was then
tested with real signals under different horizontal smoothing numbers (1, 3,
15 and 30). Finally, the results of BLH obtained by CALIPSO data were
compared with the results retrieved by the ground-based lidar measurements.
Under the horizontal smoothing number of 15, 12 and 9, the correlation
coefficients between the BLH derived by the proposed algorithm and
ground-based lidar were both 0.72. Under the horizontal smoothing number of
6, 3 and 1, the correlation coefficients between the BLH derived by graphics
distribution method (GDM) algorithm and ground-based lidar were 0.47, 0.14
and 0.12, respectively. When the horizontal smoothing number was large (15,
12 and 9), the CALIPSO BLH derived by the proposed method demonstrated a good
correlation with ground-based lidar. The algorithm provided a reliable result
when the horizontal smoothing number was greater than 9. This finding
indicated that the proposed algorithm can be applied to the CALIPSO satellite
data with 3 and 5 km horizontal resolution.
Graphics algorithm for deriving atmospheric boundary layer heights from CALIPSO data