Multi-GNSS Tomography: Case Study of the July 2021 Flood in Germany

Abstract Due to climate change, intensive storms and severe precipitation will continue happen, causing destructive flooding. In July 2021, a series of with prolonged rain episodes took place in Europe. Several countries were affected by floods following that rainfall, many deaths material damage. Thus, good understanding forecasting such events are uttermost importance. This study highlights the interest multi-GNSS tomography for 3D modelling neutral atmosphere refractivity. The tropospheric parameters have been retrieved 2021 flood Germany from two tomographic solutions different constraining options using either GPS-only or estimates. Our investigations show stand-alone solution (especially multi-GNSS) is producing more patterns refractivity, temporally stable. We compare results external observations as radiosondes GNSS radio-occultations Metop-A & -B satellites. wetter conditions than reference. However, we can see precursor information initiation deep convection ground-based technique.