Coherence between multi-instrument and multi-model atmospheric moisture retrievals in the framework of the HyMeX-SOP1

Abstract : An observational effort has been established on Menorca Island to characterize the upwind marine low-level flow during HyMeX SOP1. The ground-based Water vapour Raman Lidar (WALI), the airborne water vapour lidar LEANDRE-2 and boundary layer pressurized balloons were implemented during the first Special Observing Period and contributed to characterize water vapour variability in the vicinity of the Balearic Islands, together with the existing network of Global Positioning System receivers. Such an experimental data set is a powerful tool for checking the reliability of numerical forecast and research models. Hence an exercise of inter-comparison was carried out using the AROME-WMED and ECMWF/IFS NWP systems, and the Weather Research and Forecasting (WRF) model. We assessed the consistency of water vapour mixing ratio (WVMR) profiles and integrated water vapour contents (IWVC) derived from the different data sets. We use consistency indicators such as root mean square errors, biases and correlations. Comparison between WVMR profiles from ground-based and airborne lidars (ground-based lidar and boundary layer pressurized balloons) leads to a root mean square error lower than 1.6 g kg-1 (1.3 g kg-1) when the same air masses are sampled. We observed a good agreement between the vertical WVMR profiles derived from WALI and the numerical models with correlations higher than 0.7 and root mean square errors lower than 2 g kg-1. Regarding IWVCs, the models exhibit biases less than 2 kg m-2, root mean square errors lower than 2.3 g kg-1 and correlations higher than 0.86 when compared to WALI.