Numerical weather prediction is expected to profit considerably of an improved knowledge of the still underdetermined state of the atmospheric boundary layer. As of late, the spatially and temporally sparse existing measurements of e.g. radiosondes can be complemented with wind, temperature, and humidity profiles of ground-based remote-sensing instruments. The DWD evaluates several of those instruments for operational deployment in the framework of the project “Pilotstation”. Here, we will present the results of assimilating observations of the most mature of those systems, i.e. microwave radiometer (MWR) and Doppler lidar, into the ICON/KENDA assimilation system of the DWD.
The MWR measures brightness temperatures and thus, the profiles provided by the ICON model have to be transformed to observation space using the forward operator RTTOV-gb. We ran several assimilation experiments, especially with regard to the vertical localisation of the MWR channels. We will demonstrate how this localisation, together with the proper handling of interchannel cross-correlations, was key for obtaining a positive impact on the upper-air forecast statistics.
The Doppler lidar provides horizontal wind measurements, which exhibit a similar quality as the existing radar-wind profiler (RWP) observations and which can be assimilated directly. We will present the results of different assimilation experiments and discuss the impact in comparison with the RWP.
How to cite: Vural, J., Merker, C., Löffler, M., Knist, C., Kayser, M., and Schomburg, A.: Ground-based remote sensing of the atmospheric boundary layer: Assimilating microwave-radiometer and Doppler-lidar observations into the ICON/KENDA system, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-244, https://doi.org/10.5194/ems2022-244, 2022.
