act.retrievals.calculate_tucker_method_pbl#

act.retrievals.calculate_tucker_method_pbl(ds, velocity='radial_velocity', dis_parm='range', interval='30min', threshold=0.08, noise_variance_threshold=0.2, min_gate_height=100)[source]#

Estimation of the Planetary Boundary Layer (PBL) height from Doppler lidar radial velocity using the turbulence component of the Tucker et al. (2009) method.

For each averaging interval and range gate, the lag-1 autocorrelation of the radial velocity is used to separate the raw velocity variance into an atmospheric (turbulent) component and an instrument noise component. Since instrument noise is uncorrelated in time, it inflates the lag-0 variance but not the lag-1 autocorrelation, so the noise variance is estimated as (1 - lag-1 autocorrelation) times the raw variance, and the remainder is attributed to atmospheric turbulence.

The PBL height for each interval is identified by scanning upward from the surface for the first run of n_layers consecutive range gates whose atmospheric variance exceeds threshold; the PBL height is reported as the height of the n-th (last) gate in that run.

Note: This is a simplified implementation of the turbulence component of the Tucker et al. (2009) method and does not incorporate the shear or aerosol backscatter components described in the original paper.

References

Tucker, S. C., et al. (2009), Doppler Lidar Estimation of Mixing Height Using Turbulence, Shear, and Aerosol Backscatter Data, J. Atmos. Oceanic Technol., 26, 673-688.

Newsom, RK, and Krishnamurthy, Raglavendra. Doppler Lidar (DL) Instrument Handbook. United States: N. p., 2022. Web. doi:10.2172/1034640.

Jackson, R., O’Brien, J., Wang, J., Fytanidis, D., Muradyan, P., Grover, M., Raut, B., Collis, S., Tuftedal, M., Anderson, G., Wagner, T. J., Nesbitt, S., Tan. H., Wefer, D., & Hammond, M. (2025), The thermodynamic and kinematic structure of the planetary boundary layer for a summer lake breeze day in Chicago. Journal of Geophysical Research: Atmospheres, accepted.

Parameters:

  • ds (xarray.Dataset) – Dataset containing the radial velocity variable.

  • velocity (str) – Name of the radial (vertical) velocity variable in ds. Units should be m/s.

  • dis_parm (str) – Name of the height/range coordinate in ds.

  • interval (str) – Averaging interval, as a pandas offset alias (e.g. “10min”), over which the velocity variance and autocorrelation are computed.

  • threshold (float) – Atmospheric (turbulent) variance threshold, in the same units as velocity squared, above which a range gate is considered part of the turbulently mixed layer.

  • noise_variance_threshold (float) – Instrument noise variance threshold, in the same units as velocity squared, above which a range gate is considered to have sufficient signal-to-noise ratio to be included in the PBL height determination. The default value of 0.2 is based on the typical noise characteristics of the ARM Doppler lidars, but may need to be adjusted for other instruments.

  • min_gate_height (float) – Minimum height of the range gate to be considered for PBL height determination. This is to avoid surface noise and spurious low-level signals. The default value is 100 meters. Original dataset with the following variables added: pbl_tucker : PBL height for each averaging interval. tucker_atmospheric_variance : Atmospheric variance profile for each

    averaging interval and range gate.

    tucker_noise_varianceInstrument noise variance profile for each

    averaging interval and range gate.