Atmospheric boundary-layer gravity waves in the Netherlands: Doppler lidar observations at Cabauw atmospheric research station and North Sea wind farms

Over last few years we have collected tens of atmospheric gravity wave (GW) events, using a long-range scanning Doppler lidar at Cabauw atmospheric research station in the Netherlands, and our North Sea wind lidar network, in which short-range wind lidars are deployed on platforms within offshore wind farms. These events are ducted GWs that are trapped in the stable boundary layer and propagate horizontally, characterized by a near-monochromatic wave with vertical velocity amplitude up to a few m/s, a period of a few minutes, and duration of a hour or more. The origin of those GWs are non-orographic, and likely linked to fronts and convergence lines. These GWs can lead to a strong modulation of wind in the lower 100m’s of the atmosphere, and are therefore relevant for wind energy. 

Vertical velocity data from Doppler lidars, from either continuous vertical stare measurements or derived from wind profiling scans, provide a direct way to observe and characterize these GWs. We also consider other observations, including tower in-situ measurements at Cabauw, weather radars and our nationwide automatic lidar ceilometers (ALC) network. Together they provide 3D information on the GW event, with detailed information on the vertical profiles from Cabauw, and the spatial extent and evolution from the observational synoptic network.

Here we present two GW events. Firstly, we show observations of a GW event over the Netherlands and Belgium in the night and early morning of June 30, 2022 [1]. Two distinct GW trains were observed, both interpreted as ducted GW that are trapped in the lowermost 500 m of the stable nocturnal boundary layer. The GWs showed large vertical velocity amplitudes up to 3 m/s, resulting in strong modulations of wind, temperature, humidity, and pressure. Secondly, we present observations from the GW event over the North Sea and the Netherlands in the night and early morning of May 2, 2025. This event was also captured by multiple stations in our North Sea wind lidar network.

This work provides a starting point to further explore the occurrence and properties of (anomalous) boundary-layer gravity wave events in the Netherlands, including the North Sea. These comprehensive sets of observations may serve as a testbed for high resolution weather models that aim to capture these type of GW events and the effect they have on the (lower) atmosphere. The particular siting of our North Sea wind lidars, i.e., in the middle of large offshore wind farms, provides the possibility to study the effect of GWs on wind farm performance.

[1]  Knoop S, Assink J D, Leijnse H, Tijm S, de Haij M J, Bosveld F C, Theeuwes N E, Evers L G, Unal C and Laffineur Q 2025 “High-resolution observations of a mesoscale gravity wave event in the nocturnal boundary-layer over The Netherlands and Belgium”, submitted to Journal of Geophysical Research: Atmospheres, preprint on https://doi.org/10.22541/essoar.176478826.60490095/v1