Integrating Ground-Based and Satellite Observations to Map Fog in the Namib Desert

In this study, ground-based remote sensing and in-situ measurements are combined to characterize and estimate cloud base height (CBH) development patterns of fog and low clouds (FLC). The estimated CBH is further integrated with satellite data to map fog in the Namib Desert for the first time.

The Namib Desert, characterized by its hyper-arid conditions and frequent coverage with fog or low level stratus clouds, presents an intriguing environment for the study of low-level clouds and their vertical geometry. Understanding cloud base height (CBH) dynamics in this region is crucial for improving fog detection, particularly in distinguishing fog from low clouds in satellite data. This research aims to close existing knowledge gaps by providing, for the first time, a way to spatially map fog and separating it from other low stratiform clouds by merging ground and space-based observations.

Using ground-based remote sensing, this study reveals distinct and contrasting cloud base height (CBH) seasonality between inland and coastal locations. During the diurnal fog life cycle, stratus lowering and lifting is commonly observed during the formation and dissipation phases of the fog. A robust methodology for estimating CBH through in-situ meteorological observations. Moreover, the integration of CBH estimates with satellite products facilitates spatial mapping of fog, separating it from other low clouds. In the future, this can improve the ability to estimate fog-related water and nutrient input for this unique ecosystem.