HEFEX III: Doppler lidar RHI scans and projected ICON-LES outputs at Hintereisferner glacier (Austria)

This dataset contains Doppler lidar Range–Height Indicator (RHI) scans and high-resolution atmospheric model simulations collected and produced during the HEFEX III field campaign at Hintereisferner.

The RHI scans were performed along the glacier flowline (25°) and across the valley (115°), enabling observation of the vertical structure and spatial evolution of wind fields over the glacier. The dataset combines processed Doppler lidar observations with large-eddy simulations (LES) of the atmospheric boundary layer, allowing direct comparison between measured and simulated flow structures.

Doppler lidar observations

The observational component consists of RHI scans obtained with a Doppler lidar system (HALO StreamLine XR).

The RHI scans measure radial velocity along a vertical scanning plane aligned with the glacier flowline.

Key measurement characteristics:

• Range gate spacing: 18 m
• Maximum analysis radius: 2000 m from the lidar location
• Scanning geometry: Range–Height Indicator (RHI), 25° and 115° angles

The raw lidar data were processed using the GitHub repository
dl_toolbox, using processing mode: hpl_l1

Additional data processing

Additional manual processing steps were applied after the DL-Toolbox workflow:

1. Resampling of zenith angles:
   Zenith angles were resampled into 1° bins within the range [-90°, 90°].
2. Temporal averaging
   Data were averaged over 30-minute intervals to reduce measurement noise.
3. Coordinate transformation
   Additional Cartesian coordinates (x, z) were computed from the original zenith angle and range values to describe the spatial structure of the scan.
4. Noise filtering
   Remaining noisy measurements were removed using a radial velocity error threshold (errdv) of 0.1. This threshold was selected based on empirical testing and provided the best balance between:
   • retaining sufficient observational coverage
   • removing regions with excessive noise while preserving smooth flow structures

Model simulations

The dataset also includes large-eddy simulations performed with ICON in LES mode (ICON-LES) for the same time period as the lidar observations.

To enable direct comparison with the Doppler lidar measurements, model wind fields were transformed into radial velocity relative