act.retrievals.calculate_pbl_liu_liang#

act.retrievals.calculate_pbl_liu_liang(ds, temperature='tdry', pressure='pres', windspeed='wspd', height='alt', smooth_height=3, land_parameter=True, llj_max_alt=1500.0, llj_max_wspd=2.0)[source]#

Function for calculating the PBL height from a radiosonde profile using the Liu-Liang 2010 technique. There are some slight descrepencies in the function from the ARM implementation 1.) it imposes a 1500m (keyword) height on the definition of the LLJ and 2.) the interpolation is slightly different using python functions

Parameters:

  • ds (xarray Dataset) – Dataset housing radiosonde profile for calculations

  • temperature (str) – The name of the temperature field.

  • pressure (str) – The name of the pressure field.

  • windspeed (str) – The name of the wind speed field.

  • height (str) – The name of the height field

  • smooth_height (int) – Number of points to do a moving average on sounding height data to reduce noise

  • land_parameter (boolean) – Set to True if retrievals over land or false to retrievals over water

  • llj_max_alt (float) – Maximum altitude the LLJ 2 m/s difference should be checked against

  • llj_max_wspd (float) – Maximum wind speed threshold to use to define LLJ

Returns:

ds (xarray Dataset) – xarray dataset with results stored in pblht_liu_liang variable

References

Liu, Shuyan, and Xin-Zhong Liang. “Observed diurnal cycle climatology of planetary

boundary layer height.” Journal of Climate 23, no. 21 (2010): 5790-5809.

Sivaraman, C., S. McFarlane, E. Chapman, M. Jensen, T. Toto, S. Liu, and M. Fischer.

“Planetary boundary layer (PBL) height value added product (VAP): Radiosonde retrievals.” Department of Energy Office of Science Atmospheric Radiation Measurement (ARM) Program (United States) (2013).