A growing number of studies suggest that climate may impact the spread of COVID-19. This hypothesis is supported by data from similar viral contagions, such as SARS and the 1918 Flu Pandemic, and corroborated by US influenza data. However, the extent to which climate may affect COVID-19 transmission rates and help modeling COVID-19 risk is still not well understood. This study demonstrates that such an understanding is attainable through the development of regression models that verify how climate contributes to modeling COVID-19 transmission, and the use of feature importance techniques that assess the relative weight of meteorological variables compared to epidemiological, socioeconomic, environmental, and global health factors. The ensuing results show that meteorological factors play a key role in regression models of COVID-19 risk, with ultraviolet radiation (UV) as the main driver. These results are corroborated by statistical correlation analyses and a panel data fixed-effect model confirming that UV radiation coefficients are significantly negatively correlated with COVID-19 transmission rates.

To assess the detectability of fossil aquifers using sounding radars, we investigate the VHF attenuation characteristics of the most common sedimentary layers overlaying shallow groundwater systems in hyper-arid deserts. In particular, we quantify the dielectric and scattering losses using GPR profiles acquired over mafic dunes and sand sheets in Oman, and on the karstic limestone in Qatar, which both present radar characteristics representative of substantial portions of the upper layer of most desert environments of North Africa and the Arabian Peninsula. Understanding the amplitude and spatial variability of these losses will significantly support the ongoing development of airborne and orbital VHF sounders dedicated to large-scale groundwater mapping in hyper-arid areas [1]. Our results suggest that VHF radars with 80-100dB effective dynamic range at the surface are capable of probing the water table in hyper-arid sedimentary environments up to 70-120 m of depth, hence covering most of the shallow aquifers located in the considered area. We observe that dielectric absorption is the main loss factor in aeolian deposits, while volume scattering, controls ~60% of the overall losses in karstic environments.