Fig. 4

Boundary-layer height (m) over London estimated from WRF (red), UKV (blue) and the Doppler lidar (black triangles) 50th percentile of the vertical variance method (green dots) for the period 1200 UTC 14 May 2019 to 1200 UTC 16 May 2019. The shaded gray area indicates uncertainty range (75th–25th percentile) from the lidar-derived boundary-layer height when the vertical velocity variance profiles are used. Detailed information on the lidar-derived boundary-layer height is provided in Sect. 2.4